Reported cholera in the United States, 1992-1994: a reflection of global changes in cholera epidemiology

Abstract

Objective: To describe US cholera surveillance data from 1992 to 1994 and the domestic impact of the epidemics of Vibrio cholerae O1 in Latin America and V cholerae O139 in Asia.

Design, setting, and participants: Retrospective review of surveillance data from all cases of cholera reported to the Centers for Disease Control and Prevention (CDC) from January 1, 1992, through December 31, 1994, in the United States and its territories.

Main outcome measures: Clinical, epidemiologic, and laboratory surveillance data.

Results: From 1992 through 1994, 160 cases of cholera were reported to CDC by 20 states and 1 territory. This is a marked increase: only 136 cases were reported from 1965 through 1991. Outbreaks affecting 75 passengers on an airplane from Latin America and 5 passengers on a cruise ship in Southeast Asia accounted for 50 percent of cases. Vibrio cholerae O139 caused 6 cases (4 percent). The proportion of V cholerae O1 isolates resistant to at least 1 antimicrobial agent rose from 3 percent in 1992 to 93 percent in 1994. Of 158 patients whose location of exposure was known, 151 (96 percent) acquired infection abroad (125 in Latin America, 26 in Asia). Of 105 persons whose reason for travel was known, 31 (30 percent) were US residents who had returned to their country of origin to visit family or friends, and 65 (62 percent) were non-US residents visiting the United States from cholera-affected countries. The cholera rate among persons arriving in the United States from cholera-affected regions was 0.27 case per 100000 air travelers, not substantially increased from earlier estimates.

Conclusions: Cholera has increased in the United States since 1991, reflecting global changes in cholera epidemiology, and is now primarily travel associated and antimicrobial resistant. Most travelers were not traditional tourists; reaching them with prevention measures may be difficult. The risk of cholera to the individual traveler remains extremely low.