Summary of Notifiable Diseases — United States, 2010

Please note: An erratum has been published for this article. To view the erratum, please click here.

Prepared by

Deborah A. Adams, Coordinator, 1

Kathleen M. Gallagher, D.Sc, MPH, Division Director1

Ruth Ann Jajosky, DMD, MPH1

Jennifer Ward, MS1

Pearl Sharp1

Willie J. Anderson1

John P. Abellera, MPH1

Aaron E. Aranas, MPH, MBA1

Michelle Mayes1

Michael S. Wodajo1

Diana H. Onweh1

Meeyoung Park2

1Division of Notifiable Diseases and Healthcare Information (proposed), the Office of Surveillance, Epidemiology, and and Laboratory Services, CDC

2McKing Consulting Corporation

Preface

The Summary of Notifiable Diseases United States, 2010 contains the official statistics, in tabular and graphic form, for the reported occurrence of nationally notifiable infectious diseases in the United States for 2010. Unless otherwise noted, the data are final totals for 2010, reported as of June 30, 2011. These statistics are collected and compiled from reports sent by state health departments and territories to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). The is available at http://www.cdc.gov/mmwr/mmwr_su/mmwr_nd/. This site also includes publications from previous years.

The Highlights section presents noteworthy epidemiologic and prevention information from 2010 for selected diseases and additional information to aid in the interpretation of surveillance and disease-trend data. Part 1 contains tables illustrating incidence data for the nationally notifiable infectious diseases reported during 2010.* The tables provide the number of cases reported to CDC for 2010 and the distribution of cases by month, geographic location, and the patients' demographic characteristics (age, sex, race, and ethnicity). Part 2 contains graphs and maps that depict summary data for certain notifiable infectious diseases described in tabular form in Part 1. Part 3 contains tables that list the number of cases of notifiable diseases reported to CDC since 1979. This section also includes a table enumerating deaths associated with specified notifiable diseases reported to CDC's National Center for Health Statistics (NCHS) during 2002–2008. The Selected Reading section presents general and disease-specific references for notifiable infectious diseases. These references provide additional information on surveillance and epidemiologic concerns, diagnostic concerns, and disease-control activities.

Comments and suggestions from readers are welcome. To increase the usefulness of future editions, comments regarding the current report and descriptions of how information is or could be used are invited. Comments should be sent to Data Operations Team NNDSS, Division of Notifiable Diseases and Healthcare Information (proposed), Public Health Surveillance and Informatics Program Office (proposed) at soib@cdc.gov.

Background

The infectious diseases designated as notifiable at the national level during 2010 are listed in this section. A notifiable disease is one for which regular, frequent, and timely information regarding individual cases is considered necessary for the prevention and control of the disease. A brief history of the reporting of nationally notifiable infectious diseases in the United States is available at http://www.cdc.gov/osels/ph_surveillance/nndss/nndsshis.htm. In 1961, CDC assumed responsibility for the collection and publication of data on nationally notifiable diseases. NNDSS is neither a single surveillance system nor a method of reporting. Certain NNDSS data are reported to CDC through separate surveillance information systems and through different reporting mechanisms; however, these data are aggregated and compiled for publication purposes.

Notifiable disease reporting at the local level protects the public's health by ensuring the proper identification and follow-up of cases. Public health workers ensure that persons who are already ill receive appropriate treatment; trace contacts who need vaccines, treatment, quarantine, or education; investigate and halt outbreaks; eliminate environmental hazards; and close premises where spread has occurred. Surveillance of notifiable conditions helps public health authorities to monitor the effect of notifiable conditions, measure disease trends, assess the effectiveness of control and prevention measures, identify populations or geographic areas at high risk, allocate resources appropriately, formulate prevention strategies, and develop public health policies. Monitoring surveillance data enables public health authorities to detect sudden changes in disease occurrence and distribution, identify changes in agents and host factors, and detect changes in health-care practices.

The list of nationally notifiable infectious diseases is revised periodically. A disease might be added to the list as a new pathogen emerges, or a disease might be deleted as its incidence declines. Public health officials at state health departments and CDC collaborate in determining which diseases should be nationally notifiable. CSTE, with input from CDC, makes recommendations annually for additions and deletions. Although disease reporting is mandated by legislation or regulation at the state and local levels, state notification to CDC is voluntary. Reporting completeness of notifiable diseases is highly variable and related to the condition or disease being reported (1). The list of diseases considered notifiable varies by state and year. Current and historic national public health surveillance case definitions used for classifying and enumerating cases consistently across reporting jurisdictions are available at http://www.cdc.gov/osels/ph_surveillance/nndss/nndsshis.htm.

Infectious Diseases Designated as Notifiable at the National Level during 2010*

Anthrax†

Arboviral diseases, neuroinvasive and nonneuroinvasive

California serogroup virus

Eastern equine encephalitis virus

Powassan virus

St. Louis encephalitis virus

West Nile virus

Western equine encephalitis virus

Botulism

foodborne

infant

other (wound and unspecified)

Brucellosis†

Chancroid

infection

Cholera

Cryptosporidiosis

Cyclosporiasis†

Dengue Virus Infection

Dengue fever

Dengue hemorrhagic fever

Dengue shock syndrome

Diphtheria

Ehrlichiosis/Anaplasmosis†

Undetermined

Giardiasis

Gonorrhea

Haemophilus influenzae, invasive disease†

Hansen disease (leprosy)

Hantavirus pulmonary syndrome†

Hemolytic uremic syndrome, post-diarrheal

Hepatitis, viral

Hepatitis A, acute

Hepatitis B, acute

Hepatitis B virus, perinatal infection

Hepatitis B, chronic

Hepatitis C, acute

Hepatitis C, chronic§

Human Immunodeficiency Virus (HIV) infection**

Influenza-associated pediatric mortality

Legionellosis

Listeriosis

Lyme disease

Malaria†

Measles

Meningococcal disease

Mumps

Novel influenza A virus infections

Pertussis

Plague

Poliomyelitis, paralytic

Poliovirus infection, nonparalytic

Psittacosis†

Q fever†

Acute

Chronic

Rabies

Animal

Human†

Rubella

Rubella, congenital syndrome

Salmonellosis

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) disease

Shiga toxin-producing (STEC)

Shigellosis

Smallpox

Spotted fever rickettsiosis†¶

Streptococcal toxic-shock syndrome†

Streptococcus pneumoniae, invasive disease

Syphilis

Syphilis, congenital

Tetanus

Toxic-shock syndrome (other than streptococcal)

Trichinellosis

Tuberculosis†

Tularemia

Typhoid fever

Vancomycin-intermediate (VISA) infection

Vancomycin-resistant (VRSA) infection

Varicella (morbidity)

Varicella (mortality)

Vibriosis

Viral hemorrhagic fevers

New World Arenavirus

Crimean-Congo hemorrhagic fever virus

Ebola virus

Lassa virus

Marburg virus

Yellow fever

* This list reflects position statements CSTE approved in 2009 for national surveillance, which were implemented beginning in January 2010. The following changes were made to the 2010 list of nationally notifiable diseases: a) dengue virus and viral hemorrhagic fever were added to the list; b) coccidioidomycosis and invasive Group A disease were deleted from the list; and c) e invasive disease replaced two previously notifiable conditions: drug-resistant and , invasive disease non-drug–resistant in children aged < 5 years.

† 2010 reflects a modified surveillance case definition for this condition, per approved 2009 CSTE position statements.

¶ Previously named Rocky Mountain Spotted Fever

§ Previously named hepatitis C virus infection, past or present

** AIDS has been reclassified as HIV stage III.

Data Sources

Provisional data concerning the reported occurrence of nationally notifiable infectious diseases are published weekly in . After each reporting year, staff in state health departments finalize reports of cases for that year with local or county health departments and reconcile the data with reports previously sent to CDC throughout the year. These data are compiled in final form in the .

Notifiable disease reports are the authoritative and archival counts of cases. They are approved by the appropriate chief epidemiologist from each submitting state or territory before being published in the . Data published in or other surveillance reports produced by CDC programs might not agree exactly with data reported in the annual because of differences in the timing of reports, the source of the data, or surveillance methodology.

Data in the were derived primarily from reports transmitted to CDC from health departments in the 50 states, five territories, New York City, and the District of Columbia. Data were reported for weeks 1–52, which correspond to the period for the week ending January 9, 2010, through the week ending January 1, 2011. More information regarding infectious notifiable diseases, including case definitions, is available at http://www.cdc.gov/osels/ph_surveillance/nndss/nndsshis.htm. Policies for reporting notifiable disease cases can vary by disease or reporting jurisdiction. The case-status categories used to determine which cases reported to NNDSS are published by disease or condition and are listed in the print criteria column of the 2010 NNDSS event code list (Exhibit) available at http://www.cdc.gov/osels/ph_surveillance/nndss/nndsshis.htm.

Final data for certain diseases are derived from the surveillance records of the CDC programs listed below. Requests for further information regarding these data should be directed to the appropriate program.

Office of Surveillance, Epidemiology and Laboratory Services

National Center for Health Statistics (NCHS)
Office of Vital and Health Statistics Systems (deaths from selected notifiable diseases)

Office of Infectious Diseases (Proposed)

National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention
Division of HIV/AIDS Prevention (HIV infection diagnoses) Division of STD Prevention (chancroid; C, genital infection; gonorrhea; and syphilis) Division of Tuberculosis Elimination (tuberculosis)

National Center for Immunization and Respiratory Diseases
Influenza Division (influenza-associated pediatric mortality)
Division of Viral Diseases, (poliomyelitis, varicella [morbidity and mortality], and SARS-CoV)

National Center for Emerging and Zoonotic Infectious Diseases
Division of Vector-Borne Diseases (arboviral diseases)
Division of High-Consequence Pathogens and Pathology (animal rabies)

NCHS postcensal estimates of the resident population of the United States for July 1, 2000–July 1, 2009, by year, county, age, bridged race, Hispanic origin, and sex (Vintage 2009), prepared under a collaborative arrangement with the U.S. Census Bureau and released June 20, 2010. Available from: www.cdc.gov/nchs/nvss/bridged_race.htm as of July 23, 2010.

Populations for territories are 2009 estimates from the U.S. Census Bureau International Data Base, available at http://www.census.gov/population/international/data/idb/informationGateway.php. The choice of population denominators for incidence reported in is based on 1) the availability of census population data at the time of preparation for publication and 2) the desire for consistent use of the same population data to compute incidence reported by different CDC programs. Incidence in the is calculated as the number of reported cases for each disease or condition divided by either the U.S. resident population for the specified demographic population or the total U.S. resident population, multiplied by 100,000. When a nationally notifiable disease is associated with a specific age restriction, the same age restriction is applied to the population in the denominator of the incidence calculation. In addition, population data from states in which the disease or condition was not reportable or was not available were excluded from incidence calculations. Unless otherwise stated, disease totals for the United States do not include data for American Samoa, Guam, Puerto Rico, the Commonwealth of the Northern Mariana Islands, or the U.S. Virgin Islands.

Interpreting Data

Incidence data in the are presented by the date of report to CDC as determined by the week and year assigned by the state or territorial health department, except for the domestic arboviral diseases, which are presented by date of diagnosis. Data are reported by the state in which the patient resided at the time of diagnosis. For certain nationally notifiable infectious diseases, surveillance data are reported independently to different CDC programs. For this reason, surveillance data reported by other CDC programs might vary from data reported in the because of differences in 1) the date used to aggregate data (e.g., date of report or date of disease occurrence), 2) the timing of reports, 3) the source of the data, 4) surveillance case definitions, 5) policies regarding case jurisdiction (i.e., which state should report the case to CDC), and print criteria.

Data reported in the are useful for analyzing disease trends and determining relative disease burdens. However, reporting practices affect how these data should be interpreted. Disease reporting is likely incomplete, and completeness might vary, depending on the disease and reporting state. The degree of completeness of data reporting might be influenced by the diagnostic facilities available, control measures in effect, public awareness of a specific disease, and the resources and priorities of state and local officials responsible for disease control and public health surveillance. Finally, factors such as changes in methods for public health surveillance, introduction of new diagnostic tests, or discovery of new disease entities can cause changes in disease reporting that are independent of the true incidence of disease.

Public health surveillance data are published for selected racial/ethnic populations because these variables can be risk markers for certain notifiable diseases. Race and ethnicity data also can be used to highlight populations for focused prevention programs. However, caution must be used when drawing conclusions from reported race and ethnicity data. Different racial/ethnic populations might have different patterns of access to health care, potentially resulting in data that are not representative of actual disease incidence among specific racial/ethnic populations. Surveillance data reported to NNDSS are in either individual case-specific form or summary form (i.e., aggregated data for a group of cases). Summary data often lack demographic information (e.g., race); therefore, the demographic-specific rates presented in the might be underestimated.

In addition, not all race and ethnicity data are collected or reported uniformly for all diseases, the standards for race and ethnicity have changed over time, and the transition in implementation to the newest race and ethnicity standard has taken varying amounts of time for different CDC surveillance systems. For example, in 1990, the National Electronic Telecommunications System for Surveillance (NETSS) was established to facilitate data collection and submission of case-specific data to CDC's National Notifiable Diseases Surveillance System, except for selected diseases. In 1990, NETSS implemented the 1977 Office of Management and Budget (OMB) standard for race and ethnicity, in which race and ethnicity were collected in one variable. Other surveillance programs implemented two variables for collection of race and ethnicity data. The 1997 OMB race and ethnicity standard, which requires collection of multiple races per person using multiple race variables, should have been implemented by federal programs beginning January 1, 2003. In 2003, the CDC Tuberculosis and HIV/AIDS programs were able to update their surveillance information systems to implement 1997 OMB standards. In 2005, the Sexually Transmitted Diseases Management Information System also was updated to implement the 1997 OMB standards. However, other diseases reported to the NNDSS using NETSS were undergoing a major change in the manner in which data were collected and reported to CDC. This change is known as the transition from NETSS to the National Electronic Disease Surveillance System (NEDSS). NEDSS implemented the newer 1997 OMB standard for race and ethnicity. However, the transition from NETSS to NEDSS was slower than originally expected relative to reporting data to CDC using NEDSS; thus, some data are currently reported to CDC using NETSS formats, even if the data in the reporting jurisdictions are collected using NEDSS. Until the transition to NEDSS is complete, race and ethnicity data collected or reported to NETSS using different race and ethnicity standards will need to be converted to one standard. The data are now converted to the 1977 OMB standard originally implemented in NETSS.

Although the recommended standard for classifying a person's race or ethnicity is based on self-reporting, this procedure might not always be followed.

Transition in NNDSS Data Collection and Reporting

Before 1990, data were reported to CDC as cumulative counts rather than individual case reports. In 1990, using NETSS, states began electronically capturing and reporting individual case reports to CDC without personal identifiers. In 2001, CDC launched NEDSS, now a component of the Public Health Information Network, to promote the use of data and information system standards that advance the development of efficient, integrated, and interoperable surveillance information systems at the local, state, and federal levels. One of the objectives of NEDSS is to improve the accuracy, completeness, and timeliness of disease reporting at the local, state, and national levels. To meet this objective, CDC has developed the NEDSS Base System (NBS), a public health surveillance information system. At the time of publication, the system had been adopted by 19 reporting jurisdictions; 29 reporting jurisdictions had a state or vendor-developed NEDSS-compatible system; and 9 remaining jurisdictions were either in the process of adopting or changing their NEDSS-compatible system or were using a non-NEDSS-compatible system. A major feature of all NEDSS-compatible solutions, which includes NBS, is the ability to capture data already in electronic form (e.g., electronic laboratory results, which are needed for case confirmation) rather than enter these data manually as in NETSS. In 2010, 16 states used NBS to transmit nationally notifiable infectious diseases to CDC, 32 states used a NEDSS-compatible based system, and the remaining state and territorial jurisdictions continued to use a non-NEDSS-compatible system. Additional information concerning NEDSS is available at http://www.cdc.gov/phin/activities/applications-services/nedss/index.html.

Methodology for Identifying which Nationally Notifiable Infectious Diseases are Reportable

States and jurisdictions are sovereign entities. Reportable conditions are determined by laws and regulations of each state and jurisdiction, and some conditions deemed nationally notifiable might not be reportable in certain states or jurisdictions. Determining which nationally notifiable infectious diseases are reportable in NNDSS reporting jurisdictions was determined by analyzing results of the 2010 CSTE State Reportable Conditions Assessment (SRCA). This assessment solicited information from each NNDSS reporting jurisdiction (all 50 U.S. states, the District of Columbia, New York City, and five U.S. territories) regarding which public health conditions were reportable for more than 6 months in 2010 by clinicians, laboratories, hospitals, or other public health reporters, as mandated by law or regulation. To assist in the implementation of SRCA, the NNDSS program provided technical assistance to the CSTE for the 2010 SRCA.

In 2007, SRCA became the first collaborative project of such technical magnitude ever conducted by CSTE and CDC. Previously, CDC and CSTE had gathered public health reporting requirements independently. The 2010 SRCA collected information regarding whether each reportable condition was 1) explicitly reportable (i.e., listed as a specific disease or as a category of diseases on reportable disease lists); 2) whether it was implicitly reportable (i.e., included in a general category of the reportable disease list, such as rare diseases of public health importance); or 3) not reportable. Only explicitly reportable conditions were considered reportable for the purpose of national public health surveillance and thus reflected in NNDSS. Moreover, to determine whether a condition included in SRCA was reportable in at least one public health reporter category for a specific nationally notifiable infectious disease (NNID) in a reporting jurisdiction, CDC developed and applied an algorithm to run on the data collected in SRCA. Analyzed results of the 2010 SRCA were used to determine whether a NNID was not reportable in a reporting jurisdiction in 2010 and thus noted with an "N" indicator (for "not reportable") in the front tables of this report.

Unanalyzed results from the 2007, 2008, 2009 and 2010 SRCA are available using CSTE's web query tool at http://www.cste.org/dnn/programsandactivities/publichealthinformatics/statereportableconditionsqueryresults/tabid/261/default.aspx. Background information about the CSTE SRCA have been published previously (2).

Revised International Health Regulations

In May 2005, the World Health Assembly adopted revised International Health regulations (IHR) (3) that went into effect in the United States on July 18, 2007. This international legal instrument governs the role of the World Health Organization (WHO) and its member countries, including the United States, in identifying, responding to, and sharing information about Public Health Emergencies of International Concern (PHEIC). A PHEIC is an extraordinary event that 1) constitutes a public health risk to other countries through international spread of disease, and 2) potentially requires a coordinated international response.

The IHR are designed to prevent and protect against the international spread of diseases while minimizing the effect on world travel and trade. Countries that have adopted these rules have a much broader responsibility to detect, respond to, and report public health emergencies that potentially require a coordinated international response in addition to taking preventive measures. The IHR will help countries work together to identify, respond to, and share information about PEHIC.

The revised IHR is a conceptual shift from a predefined disease list to a framework of reporting and responding to events on the basis of an assessment of public health criteria, including seriousness, unexpectedness, and international travel and trade implications. PHEIC are events that fall within those criteria (further defined in a decision algorithm in Annex 2 of the revised IHR). Four conditions always constitute a PHEIC and do not require the use of the IHR decision instrument in Annex 2: Severe Acute Respiratory Syndrome (SARS), smallpox, poliomyelitis caused by wild-type poliovirus, and human influenza caused by a new subtype. Any other event requires the use of the decision algorithm in Annex 2 of the IHR to determine if it is a potential PHEIC. Examples of events that require the use of the decision instrument include, but are not limited to, cholera, pneumonic plague, yellow fever, West Nile fever, viral hemorrhagic fevers, and meningococcal disease. Other biologic, chemical, or radiologic events might fit the decision algorithm and also must be reportable to WHO. All WHO member states are required to notify WHO of a potential PHEIC. WHO makes the final determination about the existence of a PHEIC.

Health-care providers in the United States are required to report diseases, conditions, or outbreaks as determined by local, state, or territorial law and regulation, and as outlined in each state's list of reportable conditions. All health-care providers should work with their local, state, and territorial health agencies to identify and report events that might constitute a potential PHEIC occurring in their location. U.S. State and Territorial Departments of Health have agreed to report information about a potential PHEIC to the most relevant federal agency responsible for the event. In the case of human disease, the U.S. State or Territorial Departments of Health will notify CDC rapidly through existing formal and informal reporting mechanisms (4). CDC will further analyze the event based on the decision algorithm in Annex 2 of the IHR and notify the U.S. Department of Health and Human Services (DHHS) Secretary's Operations Center (SOC), as appropriate.

DHHS has the lead role in carrying out the IHR, in cooperation with multiple federal departments and agencies. The DHHS SOC is the central body for the United States responsible for reporting potential events to WHO. The United States has 48 hours to assess the risk of the reported event. If authorities determine that a potential PHEIC exists, the WHO member country has 24 hours to report the event to WHO.

An IHR decision algorithm in Annex 2 has been developed to help countries determine whether an event should be reported. If any two of the following four questions can be answered in the affirmative, then a determination should be made that a potential PHEIC exists and WHO should be notified:

• Is the public health impact of the event serious?
• Is the event unusual or unexpected?
• Is there a significant risk of international spread?
• Is there a significant risk of international travel or trade restrictions?

Additional information concerning IHR is available at http://www.who.int/csr/ihr/en, http://www.globalhealth.gov, http://www.cdc.gov/globalhealth/ihregulations.htm, and http://www.cste.org/PS/2007ps/2007psfinal/ID/07-ID-06.pdf. At its annual meeting in June 2007, CSTE approved a position statement to support the implementation of IHR in the United States (4). CSTE also approved a position statement in support of the 2005 IHR adding initial detections of novel influenza A virus infections to the list of nationally notifiable diseases reportable to NNDSS, beginning in January 2007 (5).

1. Doyle TJ, Glynn MK, Groseclose LS. Completeness of notifiable infectious disease reporting in the United States: an analytical literature review. Am J Epidemiol 2002;155:86–74.
2. Jajosky R, Park M, Macdonald S, Ferland L. Findings from the Council of State and Territorial Epidemiologists' 2008 assessment of state reportable and nationally notifiable conditions in the United States and considerations for the future. J Public Health Manag Pract 2011;17:255–64. Available at http://journals.lww.com/jphmp/Abstract/2011/05000/ findings from the Council of State and Territorial.9.aspx.
3. World Health Organization. Third report of Committee A. Annex 2. Geneva, Switzerland: World Health Organization; 2005. Available at http://www.who.int/gb/ebwha/pdf_files/WHA58/A58_55-en.pdf.
4. Council of State and Territorial Epidemiologists. Events that may constitute a public health emergency of international concern. Position statement 07-ID-06. Available at http://www.cste.org/PS/2007ps/2007psfinal/ID/07-ID-06.pdf.
5. Available at http://www.cste.org/PS/2007ps/2007psfinal/ID/07-ID-01.pdf.

Highlights for 2010

Below are summary highlights for certain national notifiable diseases. Highlights are intended to assist in the interpretation of major occurrences that affect disease incidence or surveillance trends (e.g., outbreaks, vaccine licensure, or policy changes).

Domestic Arboviral, Neuroinvasive and Nonneuroinvasive

During 2010, West Nile virus (WNV) disease cases were reported from 40 states and the District of Columbia. The number of reported WNV neuroinvasive disease cases increased 62% from that reported in 2009, and the reported incidence of neuroinvasive disease was 0.20 cases per 100,000 population. Despite the decline in neuroinvasive disease incidence over previous years, the overall morbidity caused by WNV continues to be substantial. Based on serosurvey results, for every case of neuroinvasive disease, there are an estimated 26.5 nonneuroinvasive disease cases. Using the 629 reported neuroinvasive disease cases, an estimated 16,669 cases of WNV nonneuroinvasive disease occurred in 2010. However, only 392 nonneuroinvasive disease cases were diagnosed and reported; 2% of the cases that are estimated to have occurred. Evidence of WNV human disease was detected in all geographic regions of the United States.The states with the highest incidence of neuroinvasive disease were Arizona (1.60 per 100,000), New Mexico (1.03), Nebraska (0.55), and Colorado (0.51). Among the neuroinvasive disease cases, 345 (55%) cases were reported from four states: Arizona (107 cases), New York (89), Texas (77), and California (72). Arizona reported 17% of all WNV neuroinvasive disease cases in 2010. New York, which reported only six neuroinvasive disease cases in 2009, reported 89 (14%) cases in 2010 (1).

Among the other domestic arboviral disease in the United States, La Crosse virus remained the most common cause of neuroinvasive disease in children and eastern equine encephalitis virus disease, although rare, remained the most severe with a 50% case-fatality rate. In 2010, the District of Columbia reported two nonneuroinvasive disease cases of St. Louis encephalitis virus (SLEV); cases of SLEV haven't been reported from this jurisdiction since 1975.

1. CDC. West Nile virus and other arboviral disease— United States, 2010. MMWR 2011;60(30):1009–13.

Botulism

Botulism is a severe paralytic illness caused by toxins produced by Clostridium botulinum. Exposure to toxin can occur by ingestion (foodborne botulism), by in situ production from C. botulinum colonization of a wound (wound botulism), or the gastrointestinal tract (infant botulism and adult intestinal colonization botulism) (1). Cases of botulism caused by all of these exposure routes were reported in 2010. Health-care providers should report suspected botulism cases immediately to their state health departments; all states maintain 24-hour telephone services for reporting botulism and other public health emergencies. CDC maintains intensive surveillance for cases of botulism in the United States and offers a 24 hour/7 day a week consultation service. The CDC botulism duty officer can be reached via the CDC Emergency Operations Center, telephone 770-488-7100.

1. Sobel J. Botulism. Clin Infect Dis 2005;41:1167–73.

Brucellosis

Compared with 2009, no change occurred in the number of reported brucellosis cases in 2010. Cases were reported from 27 states and the District of Columbia. No cases were reported from any of the U.S. territories. California, Texas, Arizona, and Florida accounted for approximately half (56.5%) of the reported cases. The geographic distribution of cases differs from those reported in 2009 when California, Florida, Georgia, Michigan, and Texas accounted for 56.5% of the reported cases. During 2010, Michigan and Georgia reported 40% and 20% decreases in cases respectively. The reason for the decline is unknown. In 2010, the number of cases reported by Arizona increased by 33%.The reason for the increase is unknown. A total of 61.3% of cases with known ethnicity occurred among Hispanics; this proportion was similar to that reported in 2009 (61.5%).

Brucellosis is a zoonotic disease caused by Brucella species. The three common pathogenic Brucella species are B. abortus, B. melitensis, and B. suis. The incubation period varies from 5 to 60 days and up to 6 months. Human infections usually occur following occupational exposure (in laboratory or veterinary settings), consumption of contaminated animal products (unpasteurized milk or cheese), or hunting.

To prevent the risk of contracting brucellosis, consumers should avoid eating or drinking unpasteurized milk and milk products or products processed through unknown methods.More information on raw milk and pasteurization can be found at http://www.cdc.gov/foodsafety/rawmilk/raw-milk-questions-and-answers.html#history.

Hunters are at an elevated risk for brucellosis from handling the carcasses or meat of infected animals. The use of gloves, aprons, or other barriers is recommended when handling animal tissue. Wild game meat also should be thoroughly cooked before consumption. Laboratory staff members should only manipulate Brucella and/or unknown isolates using biosafety level 3 (BSL-3) containment equipment and facilities. Veterinarians are considered to be at risk because of possible exposure to infected animals' blood, excretion, or other fluids. In case of accidental needle-stick injury with RB-51 vaccine, post exposure prophylaxis and serologic testing are recommended.

B. abortus, B. melitensis and B. suis are included on the list of category B bioterrorism agents. In addition to reporting cases to CDC's Bacterial Special Pathogens Branch, all laboratory exposures should be reported to the Division of Select Agents and Toxins by completing and submitting a form 3 (Report of Theft, Loss or Release of Select Agents and Toxins) as required by regulation (7 CFR 331.19, 9 CFR 121.19, and 42 CFR 73.19). The form can be downloaded from: http://www.selectagents.gov/.

1. CDC. Bioterrorism agents/diseases, by category. Atlanta, GA: US Department of Health and Human Services, CDC; 2006. Available at: http://www.bt.cdc.gov/agent/agentlist-category.asp#adef.
2. CDC, National Institutes of Health. Biosafety in microbiological and biomedical laboratories (BMBL). 5th ed. Washington, DC: US Department of Health and Human Services, CDC, National Institutes of Health; 2007. Available at: http://www.cdc.gov/biosafety/publications/bmbl5/index.htm.
3. CDC. Laboratory-acquired brucellosis—Indiana and Minnesota, 2006. MMWR 2008;57:39–42.
4. National Select Agent Registry: http://www.selectagents.gov/.

Cholera

Cholera continues to be rare in the United States. It is most often acquired during travel in countries where Vibrio cholerae is circulating (1). Epidemic cholera emerged in Haiti in October 2010, and six cases in travelers to Haiti were reported in the United States toward the end of 2010. Of the 13 cholera infections reported in the United States in 2010, all were travel-associated; six related to travel in Haiti, and the other seven reported travel to other cholera-affected countries. Until the cholera epidemic in Hispaniola wanes, more associated cases are expected in the United States (2). Cholera remains a global threat to health, particularly in areas with poor access to improved water and sanitation, such as Haiti and sub-Saharan Africa (3,4).

1. Steinberg EB, Greene KD, Bopp CA, Cameron DN, Wells JG, Mintz ED. Cholera in the United States, 1995–2000: trends at the end of the twentieth century. J Infect Dis 2001;184:799–802.
2. Newton AE, Heiman KE, Schmitz A, et al. Cholera in United States associated with epidemic in Hispaniola. Emerg Infect Dis 2011;17:2166–8.
3. Tappero J, Tauxe RV. Lessons learned during public health response to cholera epidemic in Haiti and the Dominican Republic. Emerg Infect Dis 2011;17:2087–93.
4. Mintz ED, Guerrant RL. A lion in our village – the unconscionable tragedy of cholera in Africa. New Engl J Med 2009;360:1061–3.

Cryptosporidiosis

Cryptosporidiosis incidence remained relatively stable during 2008–2010, following a >3-fold increase during 2004–2007. Whether the changes in cryptosporidiosis reporting reflect a true change in cryptosporidiosis incidence, revision to the case definition as of 2009 (i.e., adding clinical criteria to the case definition), or changing diagnosis, testing, and reporting patterns is unclear. Concerns about rapid cartridge tests led to the revision of the 2011 cryptosporidiosis case definition (1).

Although cryptosporidiosis affects persons in all age groups, cases are most frequently reported in children aged 1–9 years. A substantial increase in transmission of Cryptosporidium in these children occurs during summer through early fall, coinciding with increased use of recreational water, which is a known risk factor for cryptosporidiosis. Good hygiene practices are essential to prevention, especially in high-risk settings. Persons also should avoid food and water that might be contaminated. Cryptosporidium oocysts can be detected routinely in treated recreational water (2). Contamination of, and the subsequent transmission through, recreational water is facilitated by the substantial number of Cryptosporidium oocysts that can be shed by a single person; the extended time that oocysts can be shed (3); the low infectious dose (4); and the chlorine tolerance of Cryptosporidium oocysts (5). The application of molecular epidemiology (i.e., genotyping and subtyping Cryptosporidium specimens) to clinical and environmental samples has demonstrated potential to expand our knowledge of Cryptosporidium epidemiology (6).

1. CDC. Cryptosporidiosis 2011 case definition. Atlanta, GA: US Department of Health and Human Services, CDC; 2009. Available at http://www.cdc.gov/osels/ph_surveillance/nndss/casedef/cryptosporidiosis_current.htm.
2. Shields JM, Gleim ER, Beach MJ. Prevalence of Cryptosporidium spp. and Giardia intestinalis in swimming pools, Atlanta, Georgia. Emerg Inf Dis 2008;14:948–50.
3. Chappell CL, Okhuysen PC, Sterling CR, DuPont HL. Cryptosporidium parvum: intensity of infection and oocyst excretion patterns in healthy volunteers. J Infect Dis 1996;173:232–6.
4. Chappell CL, Okhuysen PC, Langer-Curry R, et al. Cryptosporidium hominis: experimental challenge of healthy adults. Am J Trop Med Hyg 2006;75:851–7.
5. Shields JM, Hill VR, Arrowood MJ, Beach MJ. Inactivation of Cryptosporidium parvum under chlorinated recreational water conditions. J Water Health 2008;6:513–20.
6. Xiao L. Molecular epidemiology of cryptosporidiosis: an update. Exp Parasitol 2010;124:80–89.

Dengue

During 2010, dengue became a nationally notifiable disease for the first time. In the United States, disease occurs in three epidemiologic settings. Dengue is endemic in tropical and subtropical areas, including Puerto Rico, U.S. Virgin Islands, and U.S.-affiliated Pacific Islands. In the remainder of the country, the majority of cases occur among travelers returning from dengue-endemic countries worldwide, whereas sporadic outbreaks occur from importations of dengue virus (DENV) into areas where the mosquito vector exists, such as along the U.S.-Mexico border (1), Hawaii (2), and Florida.

Dengue cases reached historically high levels in Puerto Rico during a periodic epidemic that is common to the epidemiology of this disease (3) and mirrored a period of markedly increased disease activity in the region (4). Traveler-associated dengue remains a substantial problem throughout the United States, with 642 reported cases in 2010. In October 2010, state health authorities reported a cluster of dengue-like illnesses in six of 28 missionary workers from Nebraska and Georgia who recently returned after 7–11 days in Haiti. Dengue was confirmed by laboratory testing in seven persons, all of whom had symptoms of dengue, and five were hospitalized (5).Overall, based on information reported by 85.4% of affected persons, travel-associated dengue cases originated from the following countries: Puerto Rico (93), Dominican Republic (82), India (51), Haiti (38), Nicaragua (26), Venezuela (23), Philippines (22), Colombia (21), Honduras (21), Mexico (14), Costa Rica (13), Granada (11), Guatemala (10), Jamaica (10), Bangladesh (8), Indonesia (8), St Bart's (8), Brazil (7), St. Martin (7), El Salvador (6), Guyana (6),Thailand (6), Viet Nam (6), Ecuador (5), Martinique (5), and <5 cases each from Belize, Curacao, Tanzania, Trinidad & Tobago, Cambodia, Ghana, Guadalupe, Laos, Netherlands Antilles, Pakistan, Peru, St. Thomas, Barbados, Cayman Islands, Cuba, East Timor, Liberia, Malaysia, Nigeria, Sri Lanka, St. Kitts, and Vanuatu.

In Florida, dengue reemerged in 2009 (6,7) and during 2010, 58 locally acquired dengue cases were reported. All the cases were in Key West, except for two cases in more northern counties. Clinicians should be vigilant for dengue among travelers returning from international destinations where DENV transmission is endemic or likely to be endemic (8) and should consider dengue in the differential diagnosis for persons living in areas of the United States where the disease has occurred previously. Suspected cases of dengue should be reported to public health authorities.

1. CDC. Dengue fever at the U.S.-Mexico border, 1995–1996. MMWR 1996;45:841–4.
2. Effler PV, Pang L, Kitsutani P, et.al. Dengue fever, Hawaii, 2001–2002. Emerg Infect Dis 2005;11:742–9
3. Sharp TM, Rivera A, Rodriquez-Acosta R, et al. An island-wide dengue epidemic – Puerto Rico, 2010. Am J trop Med Hyg 2011;85(suppl):400.
4. http://new.paho.org/hg/index.php?option=com_content&task=view&id=3409&itemid=1091&lang=en.
5. Sharp T, Pillai P, Hunsperger E, et. al. A cluster of dengue cases in American missionaries returning from Haiti, 2010. Am J Trop Med Hyg 2012; 86:16–22.
6. CDC. Locally acquired dengue—Key West, Florida, 2009–2010. MMWR. 2010;59:77–81.
7. Radke EG, Gregory CJ, Kintziger KW, et al. Dengue outbreak in Key West, Florida, USA, 2009. Emerg Infect Dis 2012; 18:135–7.
8. Streit JA, Yang M, Cavanaugh JE, Polgreen PM.Upward trend in dengue incidence among hospitalized patients, United States. Emerg Infect Dis 2011; 17:914–6

Ehrlichiosis and Anaplasmosis

Four categories of ehrlichiosis and anaplasmosis were reportable during 2010: 1) Ehrlichia chaffeensis, 2) Ehrlichia ewingii, 3) Anaplasma phagocytophilum, and 4) Human ehrlichiosis/anaplasmosis - undetermined.

During 2010, infections caused by E. chaffeensis were reported primarily from the lower Midwest, the Southeast, and the east coast, reflecting the currently known range of the primary tick vector species (Amblyomma americanum). Infections caused by A. phagocytophilum were reported primarily from the upper Midwest and coastal New England, reflecting both the range of the primary tick vector species (Ixodes scapularis) and preferred animal hosts for tick feeding. A total of ten cases of ehrlichiosis resulting from E. ewingii infection were reported from Missouri, Tennessee, and Delaware. The category "Human ehrlichiosis/anaplasmosis - undetermined" includes cases for which a specific etiologic agent could not be identified using available serologic tests. The high numbers of "Human ehrlichiosis/anaplasmosis - undetermined" cases reported from certain northern states (1) continue to reflect state-specific classifications based on indistinguishable antigenic cross-reactivity or situations in which physicians ordered single or inappropriate tests (e.g., ordering only ehrlichiosis tests in a region where anaplasmosisis expected to predominate).

During 2010, cases attributed to E. chaffeensis declined almost 22% (944 to 740), whereas those cases attributed to A. phagocytophilum infection increased by 52% (1,161 to 1,761). Cumulative declines in ehrlichiosis were reported by states in all geographic divisions. Increases in anaplasmosis were primarily the result of increases in numbers of cases reported by Minnesota and Wisconsin, two states that reported more than two thirds of all cases of anaplasmosis in 2010. Changes in the numbers of reported cases might be the result of several factors, including ecological changes influencing vector tick populations and disease transmission, changes in diagnostic approaches that alter detection rates, or changes in surveillance and reporting.

1. CDC. Anaplasmosis and Ehrlichiosis—Maine, 2008. MMWR 2009:58(37):1033–6.

Giardiasis

Giardia infection is the most common intestinal parasitic infection reported in the United States (1). The disease is thought to be highly underreported with an estimated 1.2 million infections occurring annually (2). Multiple factors might contribute to this under diagnosis. Giardiasis patients sometimes experience diarrhea intermittently, which might contribute to delayed diagnosis (3). Furthermore, shedding of the parasite is often intermittent, even if the symptoms are not (4). These observations form the basis for the recommendation that health-care providers test at least three stool samples collected on multiple daysr to rule out giardiasis as a cause of diarrhea (3).

Emerging evidence points to the existence of extra-intestinal and prolonged symptoms of giardiasis. A recent study of non-outbreak giardiasis cases reported that one third of patients experienced extra-intestinal symptoms, including joint pain, rash, and urinary symptoms; these symptoms often persisted more than 30 days (3). Other sequelae, including irritable bowel syndrome and fatigue, were strongly associated with a history of giardiasis 3 years after a large outbreak (5). Although these findings need further study, it is important to recognize that giardiasis symptoms can be highly variable and might cause considerable morbidity even after successful eradication of the parasite.

1. Kappus KD, Lundgren RG, Jr., Juranek DD, Roberts JM, Spencer HC. Intestinal parasitism in the United States: update on a continuing problem. Am J Trop Med Hyg. 1994;50:705–13.
2. Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States—major pathogens. Emerg Infect Dis. 2011;17:7–15.
3. Cantey PT, Roy S, Lee B, et al. Study of nonoutbreak giardiasis: novel findings and implications for research. Am J Med. 2011 [Epub ahead of print].
4. Clinical and Laboratory Standards Institute. Procedures for the recovery and identification of parasites from the intestinal tract; approved guideline. CLSI document M28-A2 Second Edition ed. Wayne, PA: Clinical and Laboratory Standards Institute; 2005.
5. Wensaas KA, Langeland N, Hanevik K, Morch K, Eide GE, Rortveit G. Irritable bowel syndrome and chronic fatigue 3 years after acute giardiasis: historic cohort study. Gut. 2011 [Epub ahead of print].

Hansen Disease (Leprosy)

In 2010, the number of reported cases of leprosy decreased by 4.8% from 2009. Cases were reported from 18 states. No cases were reported from any of the U.S. territories. Florida, Texas, California, and Hawaii accounted for 79.6% of the reported cases. Fifty percent of cases reported location of acquisition of infection as "unknown" and 24.5% did not provide a location; 25.5 % reported a location where the infection was acquired. Of those who reported a location, 72% were reported to have been acquired outside of the United States. All cases might not be newly diagnosed in the year surveillance data were collected. Providers are encouraged to contact the National Hansen Disease Program http://www.hrsa.gov/hansensdisease/ for guidance on clinical management and treatment.

Hantavirus Pulmonary Syndrome

In 2010, an imported case of hantavirus pulmonary syndrome was confirmed in a traveler from Brazil who experienced an acute illness in transit and was hospitalized in the United States. This case, along with a confirmed 2009 case of Seoul virus hemorrhagic fever and renal syndrome that occurred in a Wisconsin patient who recently traveled in China (1), serves as a reminder that hantaviral disease should be considered in patients with compatible clinical illness and a history of travel in countries endemic for hantavirus.

1. Nielsen CF, Sethi V, Petroll AE, et al. Seoul virus infection in a Wisconsin patient with recent travel to China, March 2009: first documented case in the Midwestern United States. Am J Trop Med Hyg 2010; 83: 1266–1268.

Influenza-Associated Pediatric Mortality

In June 2004, the Council of State and Territorial Epidemiologists added influenza-associated pediatric mortality (i.e., among persons aged <18 years) to the list of conditions reportable to the National Notifiable Diseases Surveillance System. Cumulative year-to-date incidence is published each week in MMWR Table I for low-incidence nationally notifiable diseases. MMWR counts of deaths are by date of report in a calendar year and not by date of occurrence. This highlight reports 61 influenza-associated pediatric deaths reported to CDC during the year 2010. Thirty two of these deaths occurred in 2009 and were reported several months later in 2010. Twenty nine deaths occurred in 2010. This compares with a mean of 65 deaths (range: 43–90) per year that have been reported for seasonal influenza during the period 2005– 2009.

Of the 61 influenza-associated pediatric deaths reported to CDC during the year 2010, the majority of pediatric deaths (53) occurred from September 2009 to June 2010. Of the 61 influenza-associated pediatric deaths reported, 56 (92%) were associated with influenza A viruses, four (7%) with influenza B viruses, and one (1%) with an untyped influenza virus. Of the 56 influenza A viruses, the subtype was determined for 39 (70%): 35 were 2009 A (H1N1) pdm09, one was seasonal A(H1N1), and three were A(H3N2) viruses.

In 2010, the median age at the time of death was 8.2 years (range: 33 days – 17.9 years). This is higher than that observed (4 – 7.5 years) before the 2009 A (H1N1) pandemic for the years 2006–2008 and January – April 2009 but lower than that seen during May 2009 – December 2009 after A (H1N1)pdm09 viruses began to circulate (9.3 years). Seven children (11%) who died were aged <6 months; 8 (13%) were aged 6–23 months; 7 (11%) were aged 24–59 months; 15 (26%) were aged 5–8years; 8 (13%) were aged 9–12 years; and the remaining 16 (26%) were aged 13–17 years. Information on death location was available for 59 of 61 children: 36 (61%) children died after being admitted to the hospital; 14 (24%) died in the emergency room; and nine (15%) died outside the hospital. Information on underlying or chronic medical condition was reported for 57 children: 36 (63%) children had one or more underlying or chronic medical conditions placing them at increased risk for influenza-associated complications (1). The most commonly reported chronic medical conditions were developmental delay (18), asthma (11), and seizure disorder (10). Of 28 children who had specimens collected for bacterial culture from normally sterile sites, test results for 14 (50%) resulted in positive cultures. Staphylococcus aureus was detected in 8 of 14 (57%) of the positive cultures; four were methicillin-resistant, three were methicillin-sensitive, and one had unknown sensitivity. The remaining specimens were positive for Pseudomonas aeruginosa, Group A Streptococcus, Streptococcus pneumoniae, Acinetobacter, Enterococcus, and Hemophilus influenzae, not type B. Of the 40 children aged ≥6 months for whom seasonal vaccination status was known, 7 (18%) were vaccinated against influenza as recommended by the Advisory Committee on Immunization Practices for 2010 (1). Continued surveillance of influenza-associated mortality is important to monitor both the effects of seasonal and novel influenza and the effect of interventions in children.

1. CDC. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP) 2010. MMWR 2010:59(No. RR-8).

Listeriosis

Listeria monocytogenes infection (listeriosis) causes rare but severe invasive disease (e.g., sepsis, meningitis, fetal death). Listeriosis has been nationally notifiable since 2000. Listeriosis is primarily acquired through contaminated food and occurs most frequently among older adults, persons who are immunocompromised, and pregnant women. Pregnancy-associated listeriosis is usually a mild illness in women but is often associated with fetal death or severe neonatal disease. During 2010, most cases occurred among persons aged ≥65 years.

Molecular subtyping of L. monocytogenes isolates and sharing that information through the National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet) has enhanced the ability of public health officials to detect and investigate outbreaks (1). Outbreaks in 2010 were linked to pre-cut celery served in chicken salad, hogs head cheese (2), and Mexican-style cheese made from pasteurized milk.

CDC recommends that all clinical isolates be submitted routinely to a state public health laboratory for molecular subtyping using pulsed-field gel electrophoresis (PFGE). Also, all persons with listeriosis should be interviewed promptly by a public health official using the standard Listeria Initiative case form, available in English and Spanish at http://www.cdc.gov/listeria_surveillance.html. Rapid analysis of molecular and epidemiologic data allows for timely identification and removal of contaminated food during outbreaks.

1. http://www.cdc.gov/pulsenet/
2. CDC. Outbreak of invasive listeriosis associated with the consumption of hog head cheese— Louisiana, 2010. MMWR 2011;60:401–05.

Lyme disease

In North America, Lyme disease is caused by Borrelia burgdorferi sensu stricto, a spirochete transmitted by certain species of Ixodes ticks. Manifestations of infection include erythema migrans, arthritis, carditis, and neurologic deficits.Human illness occurs in two major foci, one in the Northeastern and mid-Atlantic states, and one in the North-central states. Additional endemic areas occur along the Pacific coast. Effective January 2008, the national surveillance case definition was revised to include reporting of probable cases and to update laboratory criteria to reflect current testing practices.

During 2006–2009, the total number of Lyme disease cases reported to CDC increased each year, albeit with no consistent trend across states. In 2010, however, confirmed cases decreased 25% and probable cases decreased 11% as compared with 2009. In addition, regional trends were apparent. Among 12 high-incidence states in the Northeastern and mid-Atlantic regions, all but Virginia reported a decrease in confirmed cases. Conversely, the number of confirmed cases increased >20% in Minnesota and Wisconsin. The reasons for these patterns are unknown. Given the observed regional consistencies, surveillance artifact is an unlikely explanation.

Measles

Measles was declared eliminated from the United States in 2000. Since then, elimination has been maintained through high population immunity along with early detection of cases and rapid public health intervention (including contact tracing, isolation, and vaccination) (1,2). Nonetheless, because measles remains endemic in much of the world, importations continue to result in sporadic cases and outbreaks in the United States, which can be costly to control (2). In recent years, the majority (87%) of measles cases in 2010 were import associated (3). Measles was classified as internationally imported in 39 cases, 24 of which were in U.S. residents exposed while traveling abroad, and 15 of which were among international visitors. Source countries for imported cases included India (5 cases), Italy (5 cases), Ethiopia (4 cases), South Africa (3 cases), Germany, Ireland, Philippines, Switzerland, and Zambia (2 cases each), Austria, Belgium, Canada, France, Indonesia, Kuwait, Malawi, Morocco, Ukraine, United Kingdom, and Vietnam (1 case each). For the 14 internationally imported cases for which the genotype is known, genotype B3 accounted for 4 cases (2 from Ethiopia, 1 from Zambia, 1 from Germany), 3 cases were D4 (1 from India, 1 from Italy, 1 from Switzerland), 4 cases were D8 (all from India), 1 case was D9 (Indonesia), and 2 were H1 (1 from Canada and 1 from Vietnam).

Thirty-three states reported no measles cases in 2010; 10 states reported fewer than 3 cases. Four outbreaks (defined as 3 or more epidemiologically linked cases) occurred in 2010. Outbreaks were small, ranging in size from 3 to 4 cases (median: 3). Of the 47 cases that occurred in U.S. residents, 41 (87%) were unvaccinated or had undocumented vaccination status, 2 (4%) had received 1 dose of MMR vaccine, and 4 (9%) had received 2 doses of MMR vaccine. Of the 41 unvaccinated U.S. residents with measles in 2010, 36% (17/47) held personal or religious beliefs opposing vaccination. Another 13% (6/47) were missed opportunities in young U.S. resident travelers who should have been vaccinated on schedule and before their international travel (2).

1. Hutchins SS, Bellini W, Coronado V, et al. Population immunity to measles in the United States. J Infect Dis 2004;189(Suppl 1):S91–97.1.
2. CDC. Measles, mumps, and rubella–vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1998;47:1–57.
3. Parker AA, Staggs W, Dayan G, et al. Implications of a 2005 measles outbreak in Indiana for sustained elimination of measles in the United States, N Engl J Med 2006; 355:447–55.
4. Council of State and Territorial Epidemiologists. Revision of measles, rubella, and congenital syndrome case classification as part of elimination goals in the United States. Position statement 2006-ID-16. Available at http://www.cste.org/PS/2006pdfs/PSFINAL2006/06-ID-16FINAL.pdf.

Mumps

The majority (66%) of mumps cases reported in the United States during 2010 continued to be associated with a large outbreak focused in the Northeastern states (primarily New York and New Jersey) that began in New York in June 2009 (1). A total of 1,724 cases occurred January 1, 2010 through June 27, 2010.The outbreak primarily affected adolescent boys in Orthodox Jewish communities. Fewer than 3% of the cases associated with this outbreak occurred among persons outside this community.The majority (65%) of these cases occurred among males and 19% were among adolescents aged 13–17 years. Among the patients for whom vaccination status was reported, 90% had received at least 1 dose of mumps-containing vaccine, and 74% had received 2 doses. This was the largest mumps outbreak to occur in the United States since 2006 (2).

1. CDC. Update: mumps outbreak—New York and New Jersey, June 2009–January 2010. MMWR 2010; 59(5):125–30.
2. Dayan G, Quinlisk P, et al. Recent resurgence of mumps in the United States. New Engl J Med 2008;358:1580–9.

Novel Influenza A

In 2007, the Council of State and Territorial Epidemiologists added novel influenza A virus infection to the list of conditions reportable to the National Notifiable Diseases Surveillance System (1). Novel influenza A virus infections are human infections with influenza A viruses that are different from currently circulating human influenza A (H1) and A (H3) viruses. These viruses include those that are subtyped as non-human in origin and those that cannot be subtyped with standard methods and reagents used for currently circulating influenza viruses.Non-human influenza virus infections rarely result in human-to-human transmission, but the implications of sustained ongoing transmission between humans is potentially severe; therefore prompt and thorough identification and investigation of these sporadic human infections with non-human influenza viruses are needed to reduce the risk for sustained transmission (2).

In 2010, four cases of human infection with novel influenza A viruses were reported from three states: (Minnesota [2], Pennsylvania, and Wisconsin) [3]).These four cases were sporadic cases of human infection with swine-origin influenza A (H3N2) viruses. These viruses are similar to those swine influenza A (H3N2) viruses that have been circulating among U.S. pigs since 1998 (4) and ten other swine-origin influenza A (H3N2) viruses identified from previous human infections since 2009 (2).One case occurred in September (Wisconsin), one case in October (Pennsylvania), and two cases in November (Minnesota). Two of the four patients were hospitalized; all four recovered fully from their illness.Three of the four affected persons had contact with or had a likely exposure to swine and the fourth likely acquired infection from one of the persons with a confirmed case. The Wisconsin patient reported contact with pigs in the week preceding symptom onset and no direct contact with pigs was identified in the Pennsylvania case; however, the patient lives in an area close to pig farms. The two cases from Minnesota occurred in a father and child. The father had direct swine exposure 6 days before illness onset. The child had no history of recent swine exposure and her symptom onset occurred 3 days after her father's symptom onset, suggesting that she acquired the infection from exposure to her father during his illness. A nasopharyngeal swab was collected from the child and initially tested negative; her infection with swine-origin influenza A (H3N2) virus was confirmed several weeks later by serologic testing. An additional three members in the same household also had ILI during the same period, but serologic results were negative.

Transmission of swine-origin influenza A viruses to humans usually occurs among people in direct contact with pigs or in those who have visited places where pigs were present (e.g., agricultural fairs, farms, and petting zoos). CDC conducts surveillance for human infections with novel influenza A viruses year-round and carries out epidemiologic investigations on each case.Surveillance for human infections with novel influenza A viruses is essential; early identification and investigation of these cases are critical to evaluate the extent of outbreaks and the potential for human-to-human transmission.

1. Council of State and Territorial Epidemiologists. National reporting for initial detections of novel influenza A viruses. Position statement 07-ID01. Available at http://www.cste.org/PS/2007ps/2007psfinal/ID/07-ID-06.pdf.
2. CDC. Swine-origin influenza A (H3N2) virus infection in two children—Indiana and Pennsylvania, July–August 2011.MMWR2011;60:1213–5
3. CDC. Update: influenza activity—United States, 2010–11 season, and composition of the 2011–12 influenza vaccine. MMWR 2011;60:705–12
4. Vincent AL, MA W, Lager KM, Janke BH, Richt JA.Swine influenza viruses: a North American perspective. In: Maramorosch K, Slatkin AJ, Murphy FA, eds. Advances in virus research, Vol 72. Burlington:Academic Press; 2008:127–54

Psittacosis

Psittacosis is a respiratory infection resulting from exposure to the bacterium Chlamydophila (Chlamydia) psittaci through the feces, respiratory secretions, plumage, or tissues of infected birds. Persons with psittacosis generally have high fever, cough, and malaise within 5–14 days of exposure. A minority of cases might progress to severe pneumonia with respiratory compromise. The Council of State and Territorial Epidemiologists position statement and case definition for psittacosis was revised in June 2009 to include more stringent laboratory criteria for confirmed and probable cases. In 2010, a total of four psittacosis cases were reported, compared with an average of 16 (range: 9–25) cases reported during the period 2000– 2009. Additional information about psittacosis and case-reporting tools can be found at http://www.nasphv.org/documentsCompendiaPsittacosis.html.

Q fever

During 2010, both acute and chronic Q fever infections were considered notifiable. Among the 131 cases reported in 2010, 106 were acute infection, and 25 were chronic Q fever. Cases remained distributed across the United States, consistent with Q fever being enzootic in ruminants (sheep, goats, and cattle) throughout the country.

During 2010, the number of cases of Q fever reported increased 16% over those reported during the previous year. Although few human cases are reported annually, Q fever is believed to be substantially underreported because of its nonspecific presentation and the subsequent failure of physicians to suspect infection and request appropriate diagnostic tests.

Rabies

During 2010, two cases of human rabies were reported in the United States: an imported case reported from Louisiana and a domestically acquired case reported from Wisconsin. The Louisiana case originated from Mexico, and is the second imported human rabies case not associated with a canine rabies virus variant; it is also the first imported case of a human infected with the vampire bat rabies virus variant in the United States (1). The human rabies case reported from Wisconsin was associated with a bat (Perimyotis subflavus) rabies virus variant (2); in each incident, the patient died (1,2).

Each year, specimens from more than 100,000 animals are submitted for rabies diagnosis in the United States. However, during 2010, specimens for rabies diagnosis declined by more than 12% compared with 2009. The national surveillance network for rabies consists of more than 125 laboratories (state health, state agriculture, and university veterinary pathology laboratories) that perform primary diagnosis. This network is supported by local health departments, animal control services, law enforcement, private veterinarians, and the general public to ensure animals are appropriately captured, euthanized, and submitted for testing. The rabies surveillance system is robust because of the role of rabies diagnosis in animals to determine human postexposure prophylaxis decisions, yet it is susceptible to fluctuations in local policies and budgetary restrictions that affect the collection, submission, and testing of animals. (3)

Despite the overall decline in submissions and reported rabid animals during 2010, some notable epizootics occurred. Most notably a sizeable rabies epizootic in raccoons occurred around Central Park in New York City, accounting for a 400% increase in the number of reported rabid animals in the city, compared with 2009.

1. CDC. Human rabies from exposure to a vampire bat in Mexico— Louisiana, 2010. MMWR 2011; 60(31):1050–2.
2. CDC. Human rabies—Wisconsin, 2010. MMWR 2011;60(34):1164–6.
3. Blanton JD, Palmer D, Dyer J, Rupprecht CE. Rabies surveillance in the United States during 2010. J Am Vet Med Assoc. 2011;239(6):773–83.

Salmonellosis

During 2010, as in previous years, the age group with the highest incidence of salmonellosis was children aged <5 years.Salmonellosis is reported most frequently in late summer and early fall; in 2010, this seasonality was evident, with the highest number of reports in August, September, and October. Salmonella infections have not declined during the past 10 years.In 2010, the incidence was nearly three times the 2010 national health objective target (6.8 infections per 100,000 population) (1).

In the United States, Salmonella causes an estimated 1.2 million illnesses annually, approximately 1 million of which are transmitted by food consumed in the United States (2). Salmonella can contaminate several foods, and different serotypes tend to have different animal reservoirs and food sources, making control challenging. During 2010, a national outbreak of Salmonella serotype Enteritidis infections led to a massive recall of approximately 500 million eggs (3,4). This occurred just before implementation of new egg regulations, implementation of which could have prevented the outbreak and the associated recall (5).Other multistate outbreaks of Salmonella infection were linked to frozen rodents used as reptile feed (serotype I, 4,[5], 12:i:-) and to the consumption of salami products made with contaminated imported black and red pepper (serotype Montevideo), alfalfa sprouts (serotypes Newport and I, 4,[5],12:i:-), and a commercially distributed frozen chicken and rice entrée (serotype Chester).

Public health actions to prevent and control Salmonella infections are based on serotype characterization; in 2005, the Council of State and Territorial Epidemiologists adopted a position statement calling for serotype-specific reporting of laboratory-confirmed salmonellosis cases (6).Infections with certain Salmonella serotypes are more likely to be invasive and to lead to poor outcomes than infections with other serotypes (7).

1. US Department of Health and Human Services. Healthy People 2010 (midcourse review). Washington, DC: US Department of Health and Human Services; 2000.
2. Scallan E, Hoekstra Rm, Angulo FJ, et al. Foodborne illness acquired in the United States— major pathogens. Emerg Infect Dis 2011;7–15.
3. Final multistate outbreak investigation update (December 2, 2010) available at http://www.cdc.gov/salmonella/enteritidis/index.html
4. Kuehn BM. Salmonella cases traced to egg producers: findings trigger recall of more than 500 million eggs. JAMA. 2010;304(12):1316.
5. Food and Drug Administration, US Department of Agriculture, Food Safety and Inspection Service. Prevention of Salmonella Enteritidis in shell eggs during production, storage, and transportation. Final rule. Federal Register 2009;74:33029–101.
6. Council of State and Territorial Epidemiologists. Position statement 05-ID-09. Serotype specific national reporting for salmonellosis. Atlanta, GA: Council of State and Territorial Epidemiologists, 2005. Available at http://www.cste.org/PS/2005pdf/final2005/05-ID-09final.pdf.
7. Jones TF, Ingram LA, Cieslak PR, et al. Salmonellosis outcomes differ substantially by serotype. J Infect Dis 2008;198:109–14.

Shigellosis

Shigella sonnei infections continue to account for >75% of shigellosis in the United States (1). Most cases occur among young children, and large day care-associated outbreaks are common and often difficult to control (2). Some cases of shigellosis are acquired during international travel (3,4). In addition to spreading from one person to another, Shigellae can be transmitted through contaminated foods, sexual contact, and water used for drinking or recreational purposes (1). Resistance to ampicillin and trimethoprim-sulfamethoxazole among S. sonnei strains in the United States remains common (5). Shigellosis does not demonstrate marked seasonality, likely reflecting the importance of person-to-person transmission. Public health actions to prevent and control Shigella infections are based on species characterization; in 2005, the Council of State and Territorial Epidemiologists adopted a position statement calling for species-specific reporting of laboratory-confirmed shigellosis cases (6).

1. Gupta A, Polyak CS, Bishop RD, Sobel J, Mintz ED. Laboratory confirmed shigellosis in the United States, 1989–2002: epidemiologic trends and patterns. Clin Infect Dis 2004;38:1372–7.
2. Arvelo W, Hinkle J, Nguyen TA, et al. Transmission risk factors and treatment of pediatric shigellosis during a large daycare center-associated outbreak of multidrug resistant Shigella sonnei. Pediatr Infect Dis J 2009;11:976–80
3. Ram PK, Crump JA, Gupta SK, Miller MA, Mintz, ED. Review article: part II. Analysis of data gaps pertaining to Shigella infections in low and medium human development index countries, 1984–2005. Epidemiol Infect 2008;136:577–603.
4. Gupta SK, Strockbine N, Omondi M, Hise K, Fair MA, Mintz ED. Short report: emergence of Shiga toxin 1 genes within Shigella dysenteriae Type 4 isolates from travelers returning from the island of Hispanola. Am J Trop Med Hyg 2007;76:1163–5.
5. CDC. National Antimicrobial Resistance Monitoring System for enteric bacteria (NARMS): Human isolates final report, 2006. Atlanta, GA: US Department of Health and Human Services, CDC; 2009. Available at http://www.cdc.gov/narms.
6. Council of State and Territorial Epidemiologists. Position statement 05-ID-08. Serotype specific national reporting for shigellosis. Atlanta, GA: Council of State and Territorial Epidemiologists, 2005. Available at http://www.cste.org/PS/2005pdf/final2005/05-ID-08final.pdf.

Spotted Fever Rickettsiosis (including Rocky Mountain Spotted Fever)

Because serologic tests commonly used to diagnose Rocky Mountain spotted fever (RMSF) exhibit cross-reactivity between spotted fever rickettsial pathogens, some cases reported as RMSF might actually be disease caused by other spotted fever rickettsial infections, and therefore are more correctly referred to as spotted fever rickettsiosis (SFR). The Council of State and Territorial Epidemiologists approved this change at their 2009 annual meeting. The change became effective in January 2010 (1).

During 2010, SFR cases increased 9% over those reported in 2009 (1,815 to 1,985). Cases reported in 2010 were distributed across the United States, reflecting the endemic status of SFR and the widespread ranges of the primary tick vectors (primarily Dermacentor variabilis and Dermacentor andersoni) responsible for transmission. SFR cases associated with infections caused by Rhipicephalus sanguineus, first reported in 2004 (2), continued to be reported from Arizona during 2010.

Although SFR case reports increased more than 400% from 2000 through 2008 (495 to 2,563), reported case totals in 2009 and 2010 have been 29% and 23% lower. Reporting fluctuations might be the result of several factors, including ecological changes influencing vector tick populations and disease transmission, changes in diagnostic approaches that alter detection rates, or changes in surveillance and reporting practices.

1. Council of State and Territorial Epidemiologists. Revision of the surveillance case definitions for Spotted Fever Rickettsiosis (including Rocky Mountain spotted fever). Position statement 09-ID-16. Atlanta, GA: Council of State and Territorial Epidemiologists; 2009. Available at http://www.cste.org/ps2009/09-ID-16.pdf.
2. L Demma, Traeger M, Nicholson W, et al. Rocky Mountain spotted fever from an unexpected tick vector in Arizona. New Engl J Med 2005;353:587–94.

Shiga Toxin-Producing Escherichia coli (STEC)

In 2010, more Shiga toxin-producing Escherichia coli (STEC) infections were reported than in 2009. In the Foodborne Diseases Active Surveillance Network (FoodNet), which conducts active surveillance for STEC infection, the reported incidence of STEC O157 infection decreased and incidence of STEC non-O157 infection increased. Development of post-diarrheal hemolytic uremic syndrome (HUS), a severe complication of STEC infection, is most strongly associated with STEC O157. STEC non-O157 a diverse group that varies in virulence, comprises approximately 50 other serogroups. The national Healthy People 2010 target for STEC O157 infection (≤1.0 case per 100,000 population as measured in FoodNet) was met in both 2009 and 2010; the Healthy People 2020 target is 0.6 cases per 100,000 population (1).

Escherichia coli O157:H7 infection has been nationally notifiable since 1994 (2). Shiga toxin-producing E. coli (STEC) infection caused by any serotype was made nationally notifiable in 2001, originally using the nomenclature enterohemorrhagic E. coli (EHEC) and changing to STEC in 2006 (3). Public health actions to monitor, prevent, and control STEC infections are based on serogroup characterization. Increased use of assays for the detection of Shiga toxins in clinical laboratories in recent years has led to increased reporting of STEC non-O157 infection (4). Stool specimens from patients with community-acquired diarrhea submitted to clinical laboratories should be tested routinely both by culture for STEC O157 and by an assay that detects Shiga toxins (5). Detection of Shiga toxin alone is inadequate for outbreak detection; characterizing STEC isolates by serogroup and by pulsed-field gel electrophoresis pattern is important to detect, investigate, and control outbreaks.

1. CDC. Incidence and trends of infection with pathogens transmitted commonly through food—Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 1996–2010. MMWR 2011;60(22);749–55.
2. Mead PS, Griffin PM. Escherichia coli O157:H7. Lancet 1998;352:1207–12.
3. Council of State and Territorial Epidemiologists. Revision of the Enterohemorrhagic Escherichia coli (EHEC) condition name to Shiga toxin-producing Escherichia coli (STEC) and adoption of serotype specific national reporting for STEC. Position statement 05-ID-07. Atlanta, GA: Council of State and Territorial Epidemiologists; 2005. Available at http://www.cste.org/position%20statements/searchbyyear2005.asp.
4. Hoefer, D., Hurd, S. Laboratory practices for the identification of Shiga toxin–producing Escherichia coli in the United States, FoodNet Sites, 2007. Foodborne Pathogens and Disease 8(4): 555–60.
5. CDC. Recommendations for diagnosis of Shiga toxin-producing Escherichia coli infections by clinical laboratories, 2009. MMWR 2009;58(No.RR12):1–14.

Congenital Syphilis

Rates of congenital syphilis decreased during 2010 for the second consecutive year. During 2008–2010, rates decreased 16%. This decrease parallels a similar rate decrease in primary and secondary syphilis among women during 2008–2010. However, rates of congenital syphilis among black and Hispanic women were 12.3 and 3.1 times, respectively, the rate among white women during 2010 (1).

1. CDC. Sexually Transmitted Disease Surveillance, 2010. Atlanta: U.S. Department of Health and Human Services; 2011.

Primary and Secondary Syphilis

Rates of primary and secondary syphilis reached historic lows in 2000, but increased each year during 2001–2009. During 2010, overall rates of primary and secondary syphilis decreased for the first time since 2000 (1). Rates among women increased during 2004–2008 but decreased 27% during 2008–2010. Rates among men, however, continued to increase, but only by 1% during 2009–2010; this was the tenth consecutive year of increasing rates among men. Rates among men were highest among those aged 20–24 years, a marked shift from 2005, when rates were highest among men aged 35–39 years. In particular, rates among black and Hispanic men aged 20–24 years (92.5 cases and 19.8 cases per 100,000 population, respectively) were 15 times and 3 times the rate among white men aged 20–24 years (6.2 cases per 100,000 population), respectively. During 2006–2010, rates among black men aged 20–24 years increased 134%; the magnitude of this rate increase (53 cases per 100,000 population) was the greatest of any sex, age group, or race/ethnicity group (1). Recent analyses indicate that these trends of increasing primary and secondary syphilis occur mostly among young men having sex with men. (1,2)

1. CDC. Sexually Transmitted Disease Surveillance, 2010. Atlanta: U.S. Department of Health and Human Services; 2011.
2. Su JR, Beltrami JF, Zaidi AA, Weinstock HS. Primary and secondary syphilis among black and Hispanic men who have sex with men: case report data from 27 states. Ann Int Med 2011;155:145–51.

Trichinellosis

No outbreaks were reported in 2010, that was the first year since 2004 that no trichinellosis outbreaks were reported (1–3). Wild game meat was reported as the source of Trichinella infection in two cases; one person consumed wild boar and another consumed both bear and raccoon meat. Pork was the suspected source in four cases; one person reported consuming store-bought pork, one person likely acquired the infection from pork consumed during international travel, and two persons reported consuming pork frequently either at home or at restaurants. No information on source of infection was given for one case.

In May 2011, USDA lowered its recommended cooking temperature of whole cuts of pork from 160°F to 145°F. Ground pork should still be cooked to 160°F (4). Both whole cuts and ground game meat should still be cooked to 160°F (5). National trichinellosis surveillance will continue to monitor for changes in incidence following this new recommendation.

1. Kennedy ED, Hall RL, Montgomery SP, Pyburn DG, Jones JL. Trichinellosis surveillance—United States, 2002–2007. In: Surveillance Summaries, December 4, 2009. MMWR 2009;58 (No. SS-9).
2. CDC. Summary of Notifiable Diseases — United States, 2008. MMWR 2010;57(No. 54).
3. CDC. Summary of Notifiable Diseases — United States, 2009. MMWR 2011;58(No. 53).
4. U.S. Department of Agriculture (USDA), 2011. USDA Revises Recommended Cooking Temperature for All Whole Cuts of Meat, Including Pork, to 145 °F. USDA News & Events. Published May 24, 2011. Accessed November 2, 2011. http://www.fsis.usda.gov/News_&_Events/NR_052411_01/index.asp.
5. U.S. Department of Agriculture (USDA), 2011. Fact Sheets. Meat preparation: game from farm to table. Washington, D.C. Last updated May 27, 2011. Accessed November 2, 2011.

Typhoid Fever

Typhoid fever is rare in the United States, and approximately 75% of cases are associated with international travel (1). The risk of infection is highest for international travelers visiting friends and relatives in countries where typhoid fever is endemic, perhaps because they are less likely than other travelers to seek pre-travel vaccination and to observe strict safe water and food practices.The risk also is higher for travelers who visit the most highly endemic areas, such as the Indian subcontinent, even for a short time (2). From 1960 through 1999, a total of 60 outbreaks of typhoid fever were reported in the United States (3). The first domestically acquired outbreak of typhoid fever in over a decade occurred in 2010. Twelve cases were identified, and illness was linked to consumption of imported frozen mamey fruit. Mamey from the same producer in Guatemala also was implicated in the previous domestic typhoid fever outbreak, which occurred in 1999 (4).

1. Lynch MF, Blanton EM, Bulens S, et al. Typhoid fever in the United States, 1999–2006. JAMA 2009;302:898–9
2. Steinberg EB, Bishop RB, Dempsey AF, et al. Typhoid fever in travelers: who should be targeted for prevention? Clin Infect Dis 2004;39:186–91.
3. Outbreaks of typhoid fever in the United States, 1960–1999. Epidemiol Infect 2003;130:13–21.
4. Katz D, Cruz MA, Trepka MJ, Suarez JA, Fiorella PD, Hammond RM. An outbreak of typhoid fever in Florida associated with an imported frozen fruit. Clin Infect Dis 2002;186:234–9.

Varicella

Varicella was added to the nationally notifiable diseases list in 2003. Surveillance for varicella is conducted through the National Notifiable Disease Surveillance System (NNDSS). The number of states reporting varicella data to NNDSS has increased over time. In 2010, a total of 37 states and DC reported varicella cases to CDC through NNDSS, including limited varicella-specific data (e.g., vaccination status, disease severity). Information on vaccination status and disease severity was reported for 32% and 11% of the varicella cases, respectively. Sixty percent of the varicella cases that had information on vaccination history and disease severity had received varicella vaccine and 50% of those reported mild disease (<50 lesions). Collecting standard demographic, clinical, and epidemiologic data, including information on disease severity (e.g., number of lesions, hospitalizations), vaccination status (e.g., whether received varicella-containing vaccine, number of doses), and age of patients, is needed to update varicella vaccination policy.

Vibriosis

Vibriosis became a nationally notifiable condition in 2007 (1). California, Florida, and Texas report the largest numbers of cases.Vibrio parahaemolyticus, vulnificus, and alginolyticus account for approximately 75% of reported infections. In 2010, a cluster of toxigenic (producing cholera toxin) V. mimicus infections was associated with consumption of cooked crayfish (2).

1. Council of State and Territorial Epidemiologists. National reporting for non-cholera Vibrio infections (vibriosis). Position statement 06-ID-05. Atlanta, GA: Council of State and Territorial Epidemiologists; 2006.
2. CDC. Vibrio mimicus infection from consuming crayfish—Spokane, Washington 2010. MMWR; 59(42):1374.

Viral Hemorrhagic Fever

Viral hemorrhagic fever infections became reportable to the National Notifiable Diseases Surveillance System for the first time in 2010. These included infections with Ebola virus, Marburg virus, Crimean-Congo hemorrhagic fever virus, Lassa virus, Lujo virus, and the New World arenaviruses (Guaranito, Machupo, Junin, and Sabia). None of these viruses are endemic in the United States. In January 2010, a case of Lassa virus infection was confirmed in a patient who had recently traveled to Liberia, where the virus is endemic (1). The patient developed clinical illness in Liberia and sought medical attention upon return to the United States. No secondary cases were identified. This patient represents the sixth known occurrence of imported Lassa fever in the United States.

1. Amorosa V, MacNeil A, McConnell R, et al. Imported lassa fever, Pennsylvania, USA, 2010. Emerg Infect Dis 2010; 16: 1598—1600.

PART 1

Summaries of Notifiable Diseases in the United States, 2010

Abbreviations and Symbols Used in Tables

U Data not available.

N Not reportable (i.e., report of disease is not required in that jurisdiction).

— No reported cases.

Notes: Rates <0.01 after rounding are listed as 0.

Data in the MMWR Summary of Notifiable Diseases — United States, 2010 might not match data in other CDC surveillance reports because of differences in the timing of reports, the source of the data, the use of different case definitions and print criteria.