Mucosal Leishmaniasis Caused by Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in the Brazilian Amazon

Abstract

Background Leishmania (Viannia) braziliensis is a parasite recognized as the most important etiologic agent of mucosal leishmaniasis (ML) in the New World. In Amazonia, seven different species of Leishmania, etiologic agents of human Cutaneous Leishmaniasis, have been described. Isolated cases of ML have been described for several different species of Leishmania: L. (V.) panamensis, L. (V.) guyanensis and L. (L.) amazonensis.Methodology Leishmania species were characterized by polymerase chain reaction (PCR) of tissues taken from mucosal biopsies of Amazonian patients who were diagnosed with ML and treated at the Tropical Medicine Foundation of Amazonas (FMTAM) in Manaus, Amazonas state, Brazil. Samples were obtained retrospectively from the pathology laboratory and prospectively from patients attending the aforementioned tertiary care unit.ResultsThis study reports 46 cases of ML along with their geographical origin, 30 cases caused by L. (V.) braziliensis and 16 cases by L. (V.) guyanensis. This is the first record of ML cases in 16 different municipalities in the state of Amazonas and of simultaneous detection of both species in 4 municipalities of this state. It is also the first record of ML caused by L. (V.) guyanensis in the states of Pará, Acre, and Rondônia and cases of ML caused by L. (V.) braziliensis in the state of Rondônia.Conclusions/Significance L. (V.) braziliensis is the predominant species that causes ML in the Amazon region. However, contrary to previous studies, L. (V.) guyanensis is also a significant causative agent of ML within the region. The clinical and epidemiological expression of ML in the Manaus region is similar to the rest of the country, although the majority of ML cases are found south of the Amazon River.

Tilting the balance between RNA interference and replication eradicatesLeishmaniaRNA virus 1 and mitigates the inflammatory response

“…Previous studies of LRV1-dependent virulence focused primarily on Lgy; however, in humans, Lbr is associated with the larger share of MCL (14,15). Our studies extend the generality of LRV1-dependent virulence to Lbr because LRV1 + Lbr likewise induces strong TLR3-dependent cytokine responses.…”

“…In humans, Lbr is associated with cutaneous leishmaniasis, as well as the larger share of the more debilitating mucocutaneous leishmaniasis (MCL) (14,15). Although in some studies LRV1 was not correlated with MCL (16,17), in others there was a strong association (6,18,19).…”

Efficacy and Safety of Liposomal Amphotericin B for the Treatment of Mucosal Leishmaniasis from the New World: A Retrospective Study

“…Leishmania (V.) panamensis, L. (V.) guyanensis, and L. (L.) amazonensis have also been associated with ML in America, but in a few case reports and series. 8,11 In this study, no patient included was from or born in the Amazon region. However, the kDNA-PCR method was positive in 19 patients, indicating that L. (V.) braziliensis is the predominant species, although similar electrophoretic patterns may occur within related species from Viannia subgenus, as some studies have reported.…”

“…Guerra and others reported 46 cases of ML along the Amazon region, with 16 cases caused by L. (V.) guyanensis, thus showing that this species is also a significant causative agent within the region. 8 In this scenario, the use of liposomal amphotericin B requires more caution, and studies with L. (V.) guyanensis are necessary to ensure the same efficacy demonstrated with L. (V.) braziliensis.…”

“…In the Amazon region, L. (V.) guyanensis is a significant causative agent of ML. 8 ML can occur simultaneously with a cutaneous manifestation (mucocutaneous leishmaniasis). However, an important aspect of ATL is the possibility of exclusive mucosal lesions, which can occur months or even years after the onset of the primary cutaneous lesion.…”