Dissemination of Leishmanias to the organs of Syrian hamsters following intrasplenic inoculation of promastigotes

Four strains of leishmanial promastigotes were inoculated intrasplenically into male Syrian hamsters (Mesocricetus auratus). The dissemination of the parasites as amastigotes to various organs was followed at closely spaced intervals for 3.5 mo.An Israeli strain of Leishmania tropica and a strain isolated in Israel from a gerbil (Meriones shawi) displayed practically identical distribution patterns. Migration was outward from the spleen to the body surface, where intense multiplication of the amastigotes occurred, primarily in the ear pinnae and in the extremities of the limbs. A cryptic visceral infection persisted in the spleen, and most of the internal organs studied also developed cryptic infections. The bone marrow became rather heavily infected, and the epididymis, exceptionally heavily infected.An Indian strain of L. donovani led to a severe visceral infection in the spleen, liver, and bone marrow; and to mild to cryptic infections in most of the other visceral organs studied. However, no invasion of the genitalia occurred, nor did the body surface become infected.An Ethiopian strain of diffuse cutaneous leishmaniasis (DCL) was noninfective to Syrian hamsters, following either the intrasplenic or the intradermal inoculation of promastigotes.