Parasite

VL is caused by a protozoan parasite of the genus Leishmania, subgenera Leishmania and Viannia. Some 30 different species are described (10 in the old world and 20 in the new world). The distinction between the species is based on zymodemes (iso-enzymes), schizodemes (kDNA analysis with restriction enzymes), serodemes (reactions with monoclonal antibodies) and rapdemes (using PCR with random primers). Earlier on the details of parasite development in the sandfly gut was used for the classification. The species causing VL in India and East Africa regions is L donovani, while in the Mediterranean basin and Latin America is L infantum.

VL in Ethiopia is caused by L donovani. The other species that exist in Ethiopia are L aethiopica, L major and L tropica, the first being the main etiologic agent for cutaneous disease. The possibility of visceral disease by dermotrophic species is described in other countries among immune suppressed patients.