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.
Shane
A L
AL
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.
Roels
T H
TH
Goldoft
M
M
Herikstad
H
H
Angulo
F J
FJ
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