Seroepidemiology of cholera in Gulf Coastal Texas

Abstract

Single serum samples from 559 volunteers from a Texas Gulf Coast area were examined for vibriocidal antibody to Vibrio cholerae O1 (biotype El Tor, serotype Inaba) by a microtiter method. Elevated levels of vibriocidal antibody were present in 14% of the subjects. Also, 6.8% of the subjects had elevated levels of antibody to the enterotoxin of V. cholerae O1 by the immunoglobulin G enzyme-linked immunosorbent assay. Recent infection, defined on the basis of elevations in both vibriocidal and antitoxin antibodies, had occurred in 1.3% of the subjects. When subjects who reported Brucella infection, travel to a cholera-endemic area, and/or cholera vaccination within a year of the study were removed from the analysis, a prevalence of recent infection of 0.89% was obtained. Significantly higher titers of vibriocidal antibody were found in those with exposure to seawater (fishermen, shrimpers, merchant marines, and dock workers) than in those without such exposure (P < 0.005). Furthermore, titers of antitoxin antibody were significantly higher in those who consumed shellfish than in nonconsumers. Finally, titers of vibriocidal antibody were significantly higher in Vietnamese subjects than in non-Vietnamese subjects. The results of this study indicate that an endemic focus of infection with F. cholerae occurs in this area.