Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link

Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.

Volume 26, Number 2—February 2020

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

On This Page
Article Metrics

Suggested citation for this article

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.

We suspect a similar phenomenon could have occurred in Brazil, and additional analyses are required to support the authors’ conclusions. Given that mice were inoculated with clinical isolates, postanimal typing should have been done. Furthermore, linking genotyping information of cultivated (cloned) strains with a patient phenotype is risky because of the selection biases of in vitro isolation and maintenance. Using a recently developed method for direct sequencing of L. donovani complex parasites in host tissues, we demonstrated that genotypes of parasites in bone marrow samples differed from derived and cultivated isolates (M.A. Domagalska et al., unpub. data, This result most likely was due to polyclonal L. donovani infections and differences in fitness of different genotypes in vitro and in vivo. On the basis of this evidence, we recommend direct parasite sequencing in clinical samples in future work. If impossible, results based on cultured isolates should be interpreted with caution. We recommend a follow-up study to verify the possibility of Crithidia/Leishmania co-infection and the capacity of Crithidia to cause leishmaniasis-like disease as a single infection.


Malgorzata Anna DomagalskaComments to Author  and Jean-Claude DujardinComments to Author 

Author affiliations: Institute of Tropical Medicine, Antwerp, Belgium



  1. Maruyama  SR, de Santana  AKM, Takamiya  NT, Takahashi  TY, Rogerio  LA, Oliveira  CAB, et al. Non-Leishmania parasite in fatal visceral leishmaniasis–like disease, Brazil. Emerg Infect Dis. 2019;25:208892. DOIPubMed
  2. Srivastava  P, Prajapati  VK, Vanaerschot  M, Van der Auwera  G, Dujardin  JC, Sundar  S. Detection of Leptomonas sp. parasites in clinical isolates of Kala-azar patients from India. Infect Genet Evol. 2010;10:114550. DOIPubMed


Suggested citation for this article: Domagalska MA, Dujardin JC. Non-Leishmania parasite in fatal visceral leishmaniasis–like disease, Brazil. Emerg Infect Dis. 2020 Feb [date cited].

DOI: 10.3201/eid2602.191428

Original Publication Date: 12/19/2019

Related Links


Table of Contents – Volume 26, Number 2—February 2020


Please use the form below to submit correspondence to the authors or contact them at the following address:

Addresses for correspondence: Malgorzata Anna Domagalska or Jean-Claude Dujardin, Institute of Tropical Medicine, Molecular Parasitology Unit, Nationalestraat 155, B-2000 Antwerpen, Belgium; or

Send To

character(s) remaining.

Comment submitted successfully, thank you for your feedback.


Page created: December 19, 2019
Page updated: December 19, 2019
Page reviewed: December 19, 2019
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.