A survey of the distribution of dermal leishmaniasis in British Honduras

Abstract

A survey of 14 villages in British Honduras was made to estimate the incidence of dermal leishmaniasis; diagnosis of past or present infection with L. mexicana was made by using the Montenegro skin test. Infection was found throughout the whole country, highest in the central areas, and lowest in the most southern Indian villages and in the coastal villages. No infection was found among the Blue Creek Mennonites, although mestizos who had worked there claimed to have been infected. The possible role of clothes and insect-free dwellings is discussed. A male-female ratio of 5·3:1 of infection was found; probably because women spend less time in the bush. The highest prevalence was in the 36–50-year age group. The low antigenicity of L. mexicana is suggested as the reason for the absence of an immune response in the children. The ear is confirmed as the commonest site of infection; the elbow is second. Possible reasons are discussed. The presence of subclinical infection is suggested because of the large number of people with positive skin tests, who denied ever having had bay sore. The presence of “doubtful” reactions to the skin test may also be significant in this context.