October 1999
ALBANY, N.Y. - A total of 1,061 suspected cases of Escherichia coli infection have been reported in association with the Washington County Fair held Aug. 23-29, according to the New York State Department of Health (NYSDOH). The outbreak was first identified the Friday of Labor Day weekend when 12 children were hospitalized throughout northeastern New York.
"This is one of the largest E. coli outbreaks we've ever seen," said Tom Skinner, spokesman from the Centers for Disease Control and Prevention (CDC). However, the investigation is ongoing. "It may be some time before we fully know exactly how many cases were E. coli" he said, "but it's certainly one of the largest ones in the United States."
Stool cultures have confirmed 122 people were infected with the same O157:H7 strain. Most are primary cases who attended the Washington County Fair in Greenwich, N.Y., and consumed contaminated well water, or products made with contaminated well water. Approximately 10 secondary cases have been reported due to poor sanitary practices.
"We've had no new onset of illnesses, which indicates that secondary infections did not occur as would have been expected," said Kristine Smith, spokeswoman for the NYSDOH.
Two people died as a result of E. coli infection, including one 3-year-old girl who died of complications from hemolytic uremic syndrome (HUS), according to the CDC. The other death was a 79-year-old man, who died of complications from HUS and thrombotic thrombocytopenic purpura. A total of 11 children have developed HUS and 65 people have been hospitalized.
"I would assume that a good percentage of the 65 [hospitalized cases] were children," said Smith. However, she said she did not yet have a report breaking down the illnesses by age.
An environmental investigation initiated on Sept. 3 associated the outbreak with unchlorinated water from a southwest well at the fairground, well six. The well was located near a cow barn where officials suspect heavy rains led surface runoff to seep into the underground water supply which feeds the well.
On Sept. 9, epidemiologists at the New York State Public Health Laboratory used five different polymerase chain reaction assays to identify E. coli 157:H7 in well six and a connecting pipe, which supplied water to food vendors at the fair, according to the CDC. Pulsed field gel electrophoresis, known in the lay media as DNA fingerprinting, was then used which proved that isolates from the well, the water distribution system and most of the patients were similar.
Also, 50 confirmed cases of Campylobacter jejuni have been identified in addition to the E. coli cases. The cause of the C. jejuni cases is not known at this time, but the investigation is ongoing.
"At this point, we're trying to get a more definitive handle on the number of people who've been affected by the outbreak," Smith said. "Whether, in fact, they're presumptive for E. coli Campylobacter coinfection or something else. So the numbers at this time are a bit fluid."
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Cases from residents of Connecticut, Maine, Massachusetts and Vermont have been reported, as well as from 14 counties in New York in association with the outbreak. Most of the counties that reported cases - Albany, Clinton, Columbia, Essex, Franklin, Fulton, Montgomery, Rensselaer, Saratoga, Schenectady, Schoharie, Warren and Washington - are all part of New York State's Capital District. These counties are located in the northeast region of New York State, approximately "one to two hours from Albany," according to Smith.
One case was reported in Suffolk County in a person who attended the fair, which is on Long Island and not a part of the Capital District. In addition, Florida reported one case, which was an illness in a worker who had returned home after working for one of the food vendors that serviced the Washington County Fair.
Illness was also reported in another Washington County food worker, from Connecticut. This worker was employed at the vendor's next location, the Schaghticoke Fair in Rensselaer County, while symptomatic.
"Apparently, that individual got infected at the Washington County Fair and continued to work symptomatic at the Schaghticoke Fair," Smith said. "That vendor was positive for E. coli O157:H7, the outbreak strain," she said. "But thankfully, no one appears to have been infected."
Smith said that officials at the local health department in Schaghticoke remained on-duty for much of the fair, "keeping an eagle-eye on sanitary practices." Officials enforced glove use and watched for any bare-hand contact in regard to food preparation.
"They were on guard," Smith said of the health officials, "because they knew that the outbreak had started and they wanted to be very careful at their fair. And they did a good job."
To help prevent secondary transmission of infection after the Washington County outbreak, letters were sent to schools and day care centers emphasizing careful hand-washing practices and the exclusion of symptomatic children from the classroom, according to the NYSDOH. Nursing homes and hospitals were also sent letters regarding recommendations for employees and residents with diarrhea. Information was also released to the public emphasizing ways to prevent secondary infections.
On Sept. 13, the New York State health commissioner, Antonia C. Novello, MD, issued an order requiring all county fairgrounds to disinfect water used at public events. The commissioner also announced plans to review existing laws and regulations, including provisions pertaining to public water supplies, mass gatherings and temporary food vendors.
Results of a case-controlled study conducted by the NYSDOH and three representatives from the CDC revealed that people who became ill were 23 times more likely than the control group to have consumed water from well six, according to the CDC. Other possible exposures, such as consuming food at the fair and contact with manure, were not significantly associated with illness.
Epidemiologists also conducted a household survey among randomly selected Washington County residents which determined that approximately 14% of county residents who attended the fair became ill. A total of 285 households were contacted by telephone. Of these, 121 households (361 individuals) went to the fair. Illness was reported by 51 individuals (from 37 households) after attending the fair.
Approximately 200 cases of E. coli O157:H7 infection occur annually in New York State, according to NYSDOH. Most are sporadic, isolated cases. Information on this ongoing outbreak investigation can be found under Health Alerts on the NYSDOH's Web site at www.health.state.ny.us.
For more information:
- CDC. Public health dispatch: Outbreak of Escherichiacoli O157:H7 and Campylobacter among attendees of the Washington County Fair - New York, 1999. MMWR 1999;48(36)803.
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