Claudia Ramos Álvarez 3º Farmacia y Biotecnología Bilingüe
Scientist in Brazil believe to have had identified a non-Leishmania parasite that can cause disease with similar symptoms to visceral leishmaniasis (also known as Kala-Azar) caused normally by Leishmania Infatum. The identification of the parasite was done through whole-genome sequencing analysis, and the parasite was later introduced in mice to reproduce the patient´s clinical manifestations.
Phylogenomic analysis data indicated that the protozoan now discovered does not belong to the genus Leishmania. In the study carried out, 2 parasite strains, LVH60 and LVH60a, isolated from an HIV-negative man where analyzed. VL was confirmed by light microscopic examination of amastigotes in bone marrow aspirates and promastigotes in culture upon parasite isolation and by positive serologic test results.
The standard treatment was applied, but a second recurrent infection appeared 4 months later. The patient was treated then with liposomal Anfotericine B, which seemed to work, but again the infection appeared back 8 months after applied. After the appearance of atypical red papules in the skin of the patient, normally related to cutaneous leishmaniasis, the patient died due to the inefficacy of the treatments.
After comparing the genome of the parasite with the existing ones of L. braziliensis, L. amazonensis and L. infantum, they came to the conclusion that it was the same parasite that caused the visceral and the skin symptoms (normally, CL is caused by L. major). Further molecular analysis showed that the strain shared the most similarities with Crithidia fasciculata, which is a non-human infective trypanosomatid.
The conclusions are that a new trypanosomatid strain of Crithidia spp. can cause disease on humans either as a single infection or co-infecting the host with Leishmania spp. The fact that this new parasite is phylogenetically closely located to C. fasciculata increases the range of vector transmission as leishmaniasis is transmitted by female sand flies, while C. fasciculata infects only Anopheles spp. and Culex spp. mosquitoes.
Noticia original: https://wwwnc.cdc.gov/eid/article/25/11/18-1548_article
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