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Three Outbreaks of Salmonellosis Associated with Baby Poultry from Three Hatcheries --- United States, 2006
During 2006, state health departments notified CDC of three outbreaks of Salmonella species infections in persons who had been in contact with chicks and other baby poultry (ducklings, goslings, and baby turkeys) purchased at agricultural feed stores. The feed stores received the poultry from hatcheries, and each of the three outbreaks was traced to a single hatchery. For decades, baby poultry, particularly chicks and ducklings, have been known to be a source of salmonellosis (1--4). More recently, the source of birds associated with salmonellosis outbreaks has been traced back to individual hatcheries. Many persons who purchase baby poultry remain unaware that contact with these birds puts them and others who are exposed to the birds, especially children and immunocompromised persons, at risk for salmonellosis. This report describes the three outbreaks and provides recommendations for preventing transmission of Salmonella infection from birds to humans.
Hatchery A. In May 2006, during routine surveillance of laboratory results, the public health laboratory at the Michigan Department of Community Health detected a cluster of cases that were culture positive for Salmonella serotype 4,5,12,i:-. Laboratory analysis of the isolates by pulsed-field gel electrophoresis (PFGE)* yielded an indistinguishable DNA pattern that was later designated as the outbreak strain. During April--July, the laboratory isolated the outbreak strain from a total of 21 clinical samples obtained from ill persons in Michigan. Ill persons were interviewed by state public health officials and asked about symptoms and possible sources of exposure. All 21 patients reported diarrhea, and six (29%) reported bloody diarrhea. Twelve (57%) patients reported vomiting. Seven (33%) of the 21 ill patients were hospitalized for a median of 4 days (range: 1--9 days); complete data on recovery status were not available at the time of interview. The median age of hospitalized patients was 31 years (range: 7 months--79 years). The median age of all patients was 18 years (range: 7 months--79 years). Twelve (57%) patients reported exposure to baby poultry in the 7 days before illness onset; eight of these patients reported purchasing the birds as a source of meat or eggs, two patients reported purchasing the birds as family pets, and for two patients, the reason for purchase was unknown. The hatchery source of the baby poultry was determined for eight (67%) of the 12 patients who reported exposure; two patients purchased birds directly from hatchery A in Michigan, and six patients purchased birds from five different agricultural feed stores that had all received birds from hatchery A. This hatchery also was the source of chicks and ducklings that caused salmonellosis outbreaks in Michigan in 1999 and 2000 (6).
Hatchery B. On May 3, 2006, the Nebraska Health and Human Services System received a report of two children with stool-culture--confirmed salmonellosis. The health department began an investigation on May 4 and learned that the two patients both attended the same Nebraska day care center, where they had handled pet chicks brought into the center by a parent. Additional interviews at the day care center detected a total of 10 persons (nine students and one staff member) with diarrhea (three or more loose stools in 24 hours), and three (30%) with bloody diarrhea. None of the 10 persons were hospitalized. Stool samples were requested of all persons with diarrhea. Of the six additional stool samples obtained, two were positive for Salmonella serotype Montevideo. Of the four total positive stool samples, all yielded Salmonella serotype Montevideo isolates with indistinguishable PFGE DNA patterns. Three of the four children had handled the chicks, and the fourth had the opportunity to do so, although direct contact could not be confirmed.
During April--June, state public health laboratories identified in the national PulseNet database§ the same strain of Salmonella serotype Montevideo in a total of 56 patients (including those from the Nebraska day care center) from 21 states.¶ Forty-eight of these patients were interviewed during May--July by state public health officials and asked about symptoms and possible exposures. All interviewed patients reported diarrhea (three or more loose stools in 24 hours), and 25 (52%) reported bloody diarrhea. Eight (17%) patients were hospitalized for a median of 2 days (range: 1--7 days), and all fully recovered; the median age of hospitalized patients was 10 months (range: 27 days--53 years). The median age of all interviewed patients was 24 months (range: 27 days--82 years). Forty-two (88%) of the 48 interviewed patients reported exposure to baby poultry in the 5 days before illness onset. Seventeen (40%) of the interviewed patients purchased the birds for meat or eggs, 18 (43%) purchased them as pets, and for seven patients, the reason for purchase was unknown. Thirty-seven (88%) of 42 patients with exposure to baby poultry purchased the birds at a store, including at least 14 different agricultural feed stores and one general store; other patients did not report the facility from which they purchased the birds.
All 37 patients who purchased baby poultry from a store were asked whether the store provided information on preventing transmission of Salmonella species infection from birds to humans; three patients reported receiving this type of information. In addition, 31 patients who reported exposure to baby poultry were asked whether they were aware that they could contract salmonellosis from baby poultry; 24 (77%) of these patients reported being unaware that baby poultry could be a source of Salmonella species infection. The hatchery source of the baby poultry was determined for nine (21%) of the 42 patients who had been exposed to baby poultry; seven of these nine patients purchased the baby poultry from three feed stores that all received birds from hatchery B in New Mexico. PFGE analysis of isolates from baby poultry and environmental swabs from hatchery B yielded a DNA pattern that was indistinguishable from the Salmonella Montevideo outbreak strain in the patients. Hatchery B also had been identified previously as the source of chicks that caused outbreaks of human Salmonella species infections in 2002 and 2005 (New Mexico Department of Health, unpublished data, 2007).
Hatchery C. During March--May 2006, the Oregon State Public Health Laboratory identified four patients with Salmonella serotype Ohio isolates; PFGE analysis yielded indistinguishable DNA patterns. All four patients were interviewed by public health officials and asked whether they had been hospitalized and about possible sources of exposure. The median age of patients was 32 years (range: 1--77 years). One patient was hospitalized.
All four patients reported exposure to baby poultry in the days before illness onset. Three of the four patients had purchased chicks from one agricultural feed store; the source for the fourth patient was unknown. After a review of invoices from the feed store, the source for the chicks was determined to be hatchery C in neighboring Washington. Hatchery C had been identified previously as the source of chicks that caused outbreaks of salmonellosis in 1995, 1996, 2003, 2004, and 2005 (Oregon Department of Public Health, unpublished data, 2007).
To assess the prevalence of Salmonella species in chicks at retail stores, the Oregon Department of Agriculture and the Oregon Public Health Division surveyed 16 agricultural feed stores in western Oregon during February--March 2006. Although the surveys began before the outbreak was detected, the data were used to assist in the subsequent outbreak investigation. Store representatives were asked about conditions under which birds were purchased, housed, and sold. In addition, cloacal swabs from 137 chicks from the 16 stores were cultured for Salmonella; serotypes Ohio, Montevideo, or Tennessee were recovered from 25 (18%) of the chicks from 10 of the 16 stores. All agricultural feed stores with chicks whose swabs yielded Salmonella Ohio received these chicks from hatchery C.
Reported by: S Bidol, MPH, M Stobierski, DVM, Michigan Dept of Community Health. D Leschinsky, Nebraska Health and Human Svcs System. P Ettestad, DVM, C Smelser, MD, D Sena-Johnson, J Jungk, MPH, N Tafoya, P Torres, MS, New Mexico Dept of Health; F Taylor, DVM, New Mexico Dept of Agriculture. W Keene, PhD, M Plantenga, B Progulske, DVM, Oregon Dept of Public Health; R TenEyck, R Rada, L Effinger, MA, Oregon Dept of Agriculture. J Lockett, N Patel, Enteric Disease Laboratory Br; F Angulo, DVM, H Bair-Brake, DVM, Enteric Disease Epidemiology Br, Div of Foodborne Bacterial and Mycotic Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases; N Gaffga, MD, EIS Officer, CDC.
This report describes three concurrent outbreaks of salmonellosis that occurred during 2006, the first year during which more than one baby-poultry--associated salmonellosis outbreak has been recognized. These outbreaks demonstrate that salmonellosis associated with baby poultry purchased from agricultural feed stores is a source of Salmonella infection in humans and an ongoing public health problem.
Each year in the United States, an estimated 1.4 million Salmonella infections result in thousands of hospitalizations and hundreds of deaths (7). The percentage caused by contact with baby poultry remains unknown, and few measures have been implemented to prevent transmission of Salmonella organisms from baby poultry to humans.
Fewer than 20 hatcheries in the United States provide the majority of baby poultry sold in agricultural feed stores in the nation, and certain hatcheries have been implicated repeatedly as sources of baby-poultry--associated salmonellosis outbreaks. Such outbreaks might be prevented by control measures at these and other hatcheries and at agricultural feed stores, where most persons purchase baby poultry. Providing information to customers about the health risks of bird contact and providing adequate handwashing facilities might prevent such infections (8). Certain state health departments (e.g., in Washington and Oregon) have urged feed stores to display warnings and provide point-of-sale educational materials to persons purchasing baby poultry; however, such campaigns are voluntary and might not be implemented. Increased emphasis on such point-of-sale educational materials might reduce numbers of infections. Evaluation of the effectiveness of mandated point-of-sale education in reducing baby-poultry--associated salmonellosis might help guide future prevention programs.
Although the purchase of baby poultry from agricultural feed stores by persons for meat or eggs or as pets is legal in all states, a 2005 survey indicated that the sale of chicks to individual persons is regulated by law in certain states. For example, 13 states** and the District of Columbia (DC) prohibit the sale of birds that have been dyed. Arkansas, Kentucky, New York, and Wisconsin have laws establishing a minimum number of birds that can be sold to individual persons, and 12 states and DC have laws restricting the youngest age at which birds can be sold. The effectiveness of such legislation is unknown. None of the hatcheries or stores implicated in the outbreaks were in violation of state laws related to the sale of baby poultry.
The hatchery B outbreak investigation described in this report indicates that persons who purchase baby poultry usually are unaware that Salmonella species infections can be transmitted from poultry to humans. Although baby birds such as chicks and ducklings might not appear dirty, they can have feces on their feathers and beaks, areas that children are more likely to touch or place in their mouths, possibly resulting in infection. In addition, all items that have been in contact with birds, such as floors, tables, rugs, sinks, and fingers, can be contaminated with a fecal film.
To reduce the risk for illness or death from salmonellosis, persons should be educated about the risks of contact with baby poultry, should avoid contact with bird feces, and should wash their hands with soap and warm water after handling baby poultry or anything that has been in contact with them. In addition, children aged <5 years should not be allowed to handle baby chicks or other baby birds. At the community level, hatcheries should provide written information for customers at agricultural feed stores and customers who purchase directly from hatcheries, recommending ways to prevent transmission of Salmonella organisms from birds to humans. Additional information regarding health risks posed by contact with baby poultry is available at http://www.cdc.gov/healthypets/easter_chicks.htm.
* PFGE provides a DNA pattern for each isolate; closely related or indistinguishable PFGE patterns suggest a common source and can be used to distinguish outbreak cases from concurrent sporadic cases. Persons with indistinguishable PFGE patterns might be included in the case count, regardless of whether exposure to the outbreak source is confirmed.
For all investigations described in this report, if the patient was a young child, a family member was interviewed.
§ PulseNet is the molecular subtyping network for foodborne disease surveillance in the United States. Participants are public health laboratories in all 50 states and federal regulatory agency laboratories. PulseNet participants perform standardized molecular subtyping (or "fingerprinting") of foodborne disease-causing bacteria by PFGE in real time. The results (DNA fingerprints, or patterns) are then submitted electronically to central databases located at CDC, which enables rapid comparison of PFGE patterns by public health professionals nationwide (5).
¶ California, Colorado, Iowa, Illinois, Kentucky, Maine, Massachusetts, Minnesota, Missouri, Nebraska, New Jersey, New Mexico, New York, Oregon, South Dakota, Texas, Utah, Virginia, Washington, Wisconsin, and Wyoming.
** Arkansas, Florida, Illinois, Kentucky, Massachusetts, Michigan, Montana, New Jersey, New York, Pennsylvania, South Carolina, Tennessee, and Vermont.
Alabama, Arkansas, Florida, Kentucky, Massachusetts, Montana, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, and Wisconsin.
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Date last reviewed: 3/28/2007