Epidemiologic Study of Visceral Leishmaniasis in Honduras, 1975–1983

Abstract

Between 1975 and 1983, 53 patients with parasitologically proven visceral leishmaniasis (VL) and 16 patients with suspected VL were diagnosed in Honduras. The patients' ages ranged from 3 months to 10 years, but 95% were younger than 3 years old. Since 1978, when 16 patients were reported, the yearly incidence has declined, and in 1982 only 4 patients were reported. We located and interviewed the families of 57 of the 69 patients. At the onset of illness, all 57 patients lived in rural areas, and 55 lived in southern Honduras. All the patients who were discharged from the hospital alive were still living at the time of the interview. A case-control study, using age-matched neighbors as controls, showed that patients were significantly more likely to have lived in poorly constructed, wood-stick houses. We used an indirect immunofluorescence test to analyze blood samples for Leishmania antibodies from 218 family members of patients, 170 family members of controls, and 156 children living on the island of El Tigre, where 4 of the 5 most recently diagnosed patients lived. Although 15 specimens gave a positive reaction to L. donovani antigen, each gave a stronger reaction when tested against Trypanosoma cruzi antigen, suggesting that the reactions to L. donovani were false positives. A serosurvey of 279 dogs of cases and controls and from El Tigre showed that 24 had positive reactions to L. donovani antigen, but only 4 (1.4%) had higher titers to L. donovani than to T. cruzi. The results of this investigation indicate that a focus of visceral leishmaniasis exists in southern Honduras, that the type of house construction may be related to the risk of infection, and that the incidence of the disease in recent years appears to be low.