Diagnosis and identification of Leishmania species in patients with cutaneous leishmaniasis in the state of Roraima, Brazil's Amazon Region

Abstract

Background Cutaneous leishmaniasis (CL) is an endemic disease in Brazil that is highly prevalent in the northern region of the country. Although there is a continuous and growing number of cases registered in the state of Roraima, there is limited information regarding the species of Leishmania that affect the human population. In this study, we aimed to characterize which Leishmania species cause human disease in those presenting with cutaneous leishmaniasis in endemic areas of the State of Roraima. Methods We conducted a prospective surveillance study between 2016 to 2018 in health centers located in the State of Roraima, Brazil. Participants with clinical suspicion of CL were enrolled and provided lesion samples for parasitological detection by microscopy. A subset of the samples was tested by polymerase chain reaction and sequencing of the internal transcribed spacer 1 (ITS-1 PCR) for molecular species identification. Results A total of 262 participants were enrolled in this study. Of those, 129 (49.27%) were positive by parasitological examination. Most positive subjects (81.58%) were male, and most cases presented a single lesion (80.26%). ITS-1 PCR and sequencing on a subset of 76 samples allowed us to detect nine different species of Leishmania: L. (V.) braziliensis, L (V.) panamensis, L. (V.) guyanensis, L. (V.) naiffi, L. (V.) shawi, L.(V.) utingensis, L. (V.) lindenbergi, L. (L.) amazonensis and L. (L.) mexicana. Conclusions Our study provides the first assessment of circulating species of Leishmania in the State of Roraima, Brazil, and shows the high diversity in this region. This study opens the path for further research on the transmission of leishmaniasis in the northernmost Brazilian State including vector and reservoir surveillance as well as for intensification of investigation and control activities against CL in the region.

Interspecies and Intrastrain Interplay Among <em>Leishmania</em> spp. Parasites

“…Some Leishmania species are geographically restricted to an endemic area, while others are widespread. For example, one or a few species of Leishmania may circulate in an endemic area while a greater number of species my circulate in other regions, such as the Amazon region [18]. Importantly, although not yet well defined, different clones or strains may also be observed.…”

The Amazonian Tropical Bites Research Initiative, a hope for resolving zoonotic neglected tropical diseases in the One Health era

“…Over 12 million people in more than 98 countries worldwide are affected by leishmaniasis, with >1.5 million new cases of cutaneous leishmaniasis (CL) each year. 36 It is challenging to estimate the burden of leishmaniasis in the Amazon Basin; however, estimates taken for the 2004–2008 Global Burden study suggest a total of 56 936 cases for the Amazon region. 37 The Amazonian region of Madre de Dios, which connects Peru, Brazil and Bolivia, has seen a change in land use due to the increase of agriculture and logging activities.…”

Filling the gaps in Leishmania naiffi and Leishmania guyanensis genome plasticity

“…Since 1989, when the first clinical descriptions of CL by L. naiffi emerged from Brazil ( Ducharme et al 2020 ), DNA samples of this species have been retrieved from murine ( Cassia-Pires et al 2014 ; Roque and Jansen 2014 ) and sand fly hosts ( Silva et al 2021 ). Albeit rare to cause disease in humans (and in such cases, responsive to therapy), instances of CL are regularly described in connection to L. naiffi throughout South America ( Correa-Cardenas et al 2020 ; Ducharme et al 2020 ; de Almeida et al 2021 ). Some studies even denote parasite resistance to first-line therapy ( Ducharme et al 2020 ).…”