Non- Leishmania Parasite in Fatal Visceral Leishmaniasis–like Disease, Brazil

摘要

To the Editor: We read with interest the recent article describing involvement of Crithidia-related parasites in visceral leishmaniasis (VL) in Brazil (1). In 2010, we published a similar study about the identification of Leptomonas sp., another monoxenous trypanosomatid, among clinical isolates from VL patients in India: of 120 cultured isolates, 111 were typed as L. donovani and 9 as Leptomonas sp. (2). As in the Brazil study, we infected BALB/c mice with 1 Leptomonas isolate; at 45 days postinfection, we found Leptomonas and Leishmania DNA by PCR in the animals’ spleens. Assuming that sterility was preserved during the experiment, we interpreted that original infection in patients resulted from a mixture of the 2 species, Leptomonas overgrew L. donovani in culture because of substantial growth advantage of the former, and a few remaining L. donovani cells in the culture spread in the animals after inoculation because of their higher in vivo fitness.