Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file

Weekly Report: Influenza Summary Update

Week ending October 30, 2004-Week 43

Error processing SSI file

The following information may be quoted:

Synopsis:

During week 43 (October 24 - October 30, 2004)*, influenza activity was low in the United States. Fifteen (1.4%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories were positive for influenza. The proportion of patient visits to sentinel providers for influenza-like illness (ILI) and the proportion of deaths attributed to pneumonia and influenza were below baseline values. One state reported regional influenza activity, one reported local activity, and 26 states and New York City reported sporadic influenza activity. Twenty states and the District of Columbia reported no influenza activity.

Laboratory Surveillance*:

During week 43, WHO and NREVSS laboratories reported testing 1,046 specimens for influenza viruses, of which 15 (1.4%) were positive. Of these, 2 were influenza A (H3N2) viruses, 10 were influenza A viruses that were not subtyped, and 3 were influenza B viruses.

Since October 3, WHO and NREVSS laboratories have tested a total of 4,736 specimens for influenza viruses and 40 (0.8%) were positive. Among the 40 influenza viruses, 30 (75.0%) were influenza A viruses and 10 (25.0%) were influenza B viruses. Thirteen (43.3%) of the 30 influenza A viruses have been subtyped and all were influenza A (H3N2) viruses. Fourteen states from 7 of the 9 surveillance regions** have reported laboratory-confirmed influenza this season.

INFLUENZA Virus Isolated


View Chart Data

Antigenic Characterization:

Since October 1, 2004, CDC has antigenically characterized 3 influenza viruses collected by U.S. laboratories. All were influenza A (H3N2) viruses and were characterized as A/Fujian/411/2002-like, which is the influenza A (H3N2) component recommended for the 2004-05 influenza vaccine.

Pneumonia and Influenza (P&I) Mortality Surveillance*:

During week 43, 6.4% of all deaths reported by the vital statistics offices of 122 U.S. cities were reported as due to pneumonia or influenza. This percentage is below the epidemic threshold of 6.9% for week 43.

Pneumonia And Influenza Mortality

View Full Screen

Influenza-Associated Pediatric Mortality*:

As of week 43, no influenza-associated pediatric deaths have been reported to CDC.

Influenza-Associated Pediatric Hospitalizations:

The New Vaccine Surveillance Network consists of three sites in Cincinnati OH, Nashville TN, and Rochester NY. The sites conduct population-based surveillance for laboratory-confirmed influenza among children 0 - 4 years of age who are admitted to the hospital with fever or acute respiratory illnesses. During October 3 - October 16, 2004, there were no laboratory-confirmed influenza-associated hospitalizations for children 0 - 4 years old. Hospitalization rate estimates are preliminary and may change as data continue to be collected.

Emerging Infections Programs (EIP) in 9 sites are collecting data on laboratory-confirmed, influenza-associated hospitalizations among children less than 18 years of age. Hospitalization data from the EIP sites will be included as they become available.

Influenza-like Illness Surveillance*:

During week 43, 1.2%*** of patient visits to U.S. sentinel providers were due to ILI. This percentage is less than the national baseline of 2.5%. On a regional level**, the percentage of visits for ILI ranged from 0.5% to 2.4%. Due to wide variability in regional level data, it is not appropriate to apply the national baseline to regional level data.

Bar Chart for Influenza-like Illness
View Chart Data | View Full Screen

Influenza Activity as Assessed by State and Territorial Epidemiologists*:

One state (New York) reported regional influenza activity and 1 state (Texas) reported local influenza activity. Twenty-six states (Alaska, Arizona, California, Connecticut, Florida, Georgia, Hawaii, Idaho, Indiana, Kansas, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, North Carolina, North Dakota, Ohio, Rhode Island, Tennessee, Virginia, Wisconsin, and Wyoming) and New York City reported sporadic influenza activity. Twenty states and the District of Columbia reported no influenza activity, and 2 states did not report.

U. S. map for Weekly Influenza Activity
View Full Screen

--------------------------------------------------------------------------------

* Reporting is incomplete for this week. Numbers may change as more reports are received.

** Surveillance Regions: New England (Connecticut, Maine, Massachusetts, New Hampshire, Vermont, Rhode Island); Mid-Atlantic (New Jersey, New York City, Pennsylvania, Upstate New York); East North Central (Illinois, Indiana, Michigan, Ohio, Wisconsin); West North Central (Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota); South Atlantic (Delaware, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, Washington, D.C., West Virginia); East South Central (Alabama, Kentucky, Mississippi, Tennessee); West South Central (Arkansas, Louisiana, Oklahoma, Texas); Mountain (Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming); Pacific (Alaska, California, Hawaii, Oregon, Washington)

*** The national and regional percentage of patient visits for ILI is weighted on the basis of state population.

Report prepared: November 4, 2004

Error processing SSI file
Error processing SSI file
Error processing SSI file
Error processing SSI file