A serosurvey for leptospirosis in Trinidad among urban and rural dwellers and persons occupationally at risk.

A survey for leptospiral antibodies was made of 1,375 persons in northern Trinidad between mid-1977 and mid-1978. The subjects were employees in seven occupational categories thought to entail a high risk of exposure to leptospires, and members of the general population of three rural and two urban communities. They were questioned inter alia about their leisure and occupational activities, household water supply and effluent, and contact with animals. Leptospiral infection was found to be widespread in the general population but not primarily associated with employment. Among the occupational groups the highest prevalence of antibodies was found in sugar-cane workers (45% infected), while among the communities prevalence was highest in the rural village of Cacandee (37%) and lowest in Woodbrook (Port-of-Spain) (5%). Keeping cattle, hunting and walking barefoot in the countryside were significantly associated with leptospiral serology. Over-all, serogroups Icterohaemorrhagiae and Autumnalis each accounted for about 25% of the seropositives in the general population. Among the occupational groups Autumnalis was the most commonly found (36%). It accounted for 42% of the seropositive sugar-cane workers and 57% of the seropositive rice farmers.