Dermal leishmaniasis in British Honduras - the parasite

ABSTRACT

This disease is largely restricted to forest workers and is manifested by localised sores which often causes considerable disfigurement. The causative organism, Leishmania braziliensis mexiccura, is readily demonstrable in stained smears of early lesions, but this becomes increasingly difficult as the infection becomes chronic. Culture in NNN medium supplements microscopic examination. The ear is most commonly involved and lesions there tend to become chronic. Active infection may protect against re-infection but the possibility of long-term immunity is not yet classified. Infected Phlebotomine sand flies and infected rodents were found to co-exist in a selected area of forest where numerous human cases of proven leishmaniasis were found. It is suggested that the disease in British Honduras is a zoonosis. The parasites is maintained in certain rodent populations which act as intermediaries for the Phlebotomes which prey on these rodents and on man. The infected rodents found to date include the Tree-rat (Ototylomus Sp.) White-footed rat (Peromyscus Sp.) and the Spiny-ocket mouse (Heteromys Sp.) (AU)