A large food-borne outbreak of group A streptococcal pharyngitis in an industrial plant: potential for deliberate contamination.
Contamination of food with streptococci could present with unusual outbreaks that may be difficult to recognize in the early stages. This is demonstrated in a large food-borne outbreak of streptococcal pharyngitis that occurred in 2003 in a factory in Israel. The outbreak was reported to the public health services on July 2 and an epidemiologic investigation was initiated. Cases and controls were interviewed and throat swabs were taken. An estimated 212 cases occurred within the first 4 days, the peak occurring on the second day. There was a wave of secondary cases during an additional 11 days. The early signs were of a respiratory illness including sore throat, weakness and fever, with high absenteeism rates suggesting a respiratory illness. As part of a case-control study, cases and controls were interviewed and throat swabs taken. Illness was significantly associated with consumption of egg-mayonnaise salad (odds ratio 4.2, 95% confidence interval 1.4-12.6), suggesting an incubation period of 12-96 hours. The initial respiratory signs of food-borne streptococcal pharyngitis outbreaks could delay the identification of the vehicle of transmission. This could be particularly problematic in the event of deliberate contamination.
Kaluski
Dorit Nitzan
DN
Public Health Services, Ministry of Health,Jerusalem, Israel.
Barak
Estrella
E
Kaufman
Zalman
Z
Valinsky
Lea
L
Marva
Esther
E
Korenman
Zina
Z
Gorodnitzki
Zeev
Z
Yishai
Ruth
R
Koltai
Deborah
D
Leventhal
Alex
A
Levine
Shimon
S
Havkin
Ofra
O
Green
Manfred S
MS
D023482:Bioterrorism; D016022:Case-Control Studies; D004196:Disease Outbreaks; D004531:Eggs / Q000382:microbiology; D004812:Epidemiologic Methods; D005516:Food Microbiology; D006801:Humans; D007221:Industry; D007557:Israel / Q000453:epidemiology; D009784:Occupational Diseases / Q000453:epidemiology* / Q000382:microbiology*; D010612:Pharyngitis / Q000453:epidemiology* / Q000382:microbiology*; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000302:isolation & purification*