Foodborne disease in our global village: a multinational investigation of an outbreak of Salmonella serotype Enteritidis phage type 4 infection in Puerto Vallarta, Mexico.
OBJECTIVE
In late 1996, a multinational investigation was launched following an outbreak of diarrheal illness that caused the disruption of an international scientific conference at a first-class hotel in Puerto Vallarta, Mexico.


METHODS
A questionnaire was mailed to all American and to selected international attendees. Additional copies of the questionnaire were provided for any family members who may have attended the conference. A case was defined as an illness with three or more loose stools during a 24-h period in a conference attendee or accompanying family member, with illness lasting 2 or more days and onset between 6 and 9 November 1996.


RESULTS
Questionnaires were returned by 81% (232/288) of American attendees, 47% (18/38) of selected international attendees, and 25 family members; 30% (83/275) of respondents met the case definition. Ill persons resided in at least seven countries. Salmonella serotype Enteritidis phage type 4 was isolated from stool specimens from patients residing in Canada, the UK, and the USA. Attending a hotel banquet on 6 November was associated with illness; 42% (82/194) of banquet attendees became ill versus 3% (1/37) of non-attendees (relative risk (RR)515.6, 95% confidence interval (CI)52.3-108.9). The only banquet food item associated with illness was chili rellenos; 53% (58/109) of persons who ate chili rellenos were ill versus 22% (12/55) of those who did not (RR52.4, 95% CI51.4-4.1). Chili rellenos ingredients included shelled eggs and cheese; Salmonella was isolated from the leftover cheese but the isolate was not serotyped.


CONCLUSIONS
Salmonella may be a cause of traveler's diarrhea and can result in outbreaks even among travelers who follow routine precautions (i.e. staying in a first-class hotel and eating hot foods). International collaboration in investigating similar outbreaks, including sharing subtyping results, will be necessary for long-term prevention. Global Salm-Surv, an international network of Salmonella reference laboratories coordinated by the World Health Organization, may facilitate such collaboration.
Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
A L
AL
Shane
T H
TH
Roels
M
M
Goldoft
H
H
Herikstad
F J
FJ
Angulo
D000328:Adult; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D004196:Disease Outbreaks; D005260:Female; D005506:Food Contamination; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000382:microbiology* / Q000503:physiopathology; D012477:Salmonella enteritidis / Q000145:classification* / Q000302:isolation & purification*; D011795:Surveys and Questionnaires; D013997:Time Factors