Experimental Transmission of Leishmania Mexicana by a North American Sand Fly, Lutzomyia Anthophora (Diptera: Psychodidae)1

The results of 2 laboratory studies on the transmission of Leishmania mexicana mexicana by the sand fly Lutzomyia anthophora are presented. Hamsters and BALB/c mice served both as the infected source and recipient hosts in the respective studies. In the 1st experiment, 68% (172/252) of the sand flies that fed on leishmanial histiocytomas of hamsters infected with a strain of L. mexicana mexicana (WHO Code Reference: MHOM/US/80/WR-411) became infected. Transmission to hamsters occurred 4–7 days after the infective blood meal, and the bite of a single infected fly was sufficient to transmit the parasite. Leishmania infection did not affect Lu. anthophora longevity, fecundity, or the proportion of females that laid eggs. In the 2nd experiment, 30.4% (91/299) of the sand flies became infected with another strain of L. mexicana mexicana (WHO Code Reference: MHOM/PA/78/49*WR-225). Although 76 infected sand flies fed on 46 individual BALB/c mice, no transmission occurred. The experimental transmission of L. mexicana mexicana by Lu. anthophora to hamsters is the first reported transmission of leishmaniasis by a sand fly that occurs in the USA.