Universidade Estadual do Maranhão, Programa de Pós-Graduação em Biodiversidade, Ambiente e Saúde, Laboratório de Entomologia Médica, Caxias, Maranhão, Brazil.
Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular de Insetos, Rio de Janeiro, Rio de Janeiro, Brazil.
Rev Inst Med Trop Sao Paulo. 2022 May 6;64:e32. doi: 10.1590/S1678-9946202264032. eCollection 2022.
Leishmaniasis is a serious public health concern in the Northeastern region of Brazil, where the sand fly fauna is well studied, although few species have been identified as competent vectors. The detection of Leishmania spp. parasites in wild-caught sand flies could help sanitary authorities draw strategies to avoid the transmission of the parasites and, therefore, the incidence of leishmaniases. We detected Leishmania DNA in wild-caught sand flies and correlated that data with aspects of sand fly ecology in the Caxias municipality, Maranhao State, Brazil. The sand flies were sampled in the peridomicile (open areas in the vicinity of human residences) and intradomicile (inside the residences) from July/2019 to March/2020. Leishmania DNA was detected in females, targeting a fragment of the Internal Transcribed Spacer (ITS1) from ribosomal DNA. Among the fourteen species of sand flies identified, five (Lutzomyia longipalpis, Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia trinidadensis, and Micropygomyia quinquefer) harbored DNA of Leishmania (Leishmania) amazonensis. The most abundant species in rural (Ny. whitmani: 35.2% and Ev. evandroi: 32.4%) and urban areas (Lu. longipalpis: 89.8%) are the permissive vectors of L. (L.) amazonensis, especially Ny. whitmani, a known vector of causative agents of cutaneous leishmaniasis. Although Lu. longipalpis is the vector of L. (L.) infantum, which was not detected in this study, its permissiveness for the transmission of L. (L.) amazonensis has been reported. We suspect that visceral leishmaniasis and cutaneous leishmaniasis are caused by L. (L.) amazonensis, and the transmission may be occurring through Lu. longipalpis, at least in the urban area.
利什曼病是巴西东北部一个严重的公共卫生问题，该地区的沙蝇区系研究得很好，但已鉴定出的有传播能力的物种很少。在野外捕获的沙蝇中检测到利什曼原虫寄生虫，可以帮助卫生当局制定避免寄生虫传播的策略，从而避免利什曼病的发生。我们在野外捕获的沙蝇中检测到了利什曼原虫 DNA，并将该数据与巴西马拉尼昂州卡西亚斯市沙蝇生态学的各个方面相关联。从 2019 年 7 月到 2020 年 3 月，在半居室（靠近人类住家的开放区域）和居室（住家内）中采集沙蝇。针对核糖体 DNA 的内部转录间隔区（ITS1）的片段，从雌性沙蝇中检测到利什曼原虫 DNA。在所鉴定的 14 种沙蝇中，有 5 种（长角沙蝇、白蛉属、伊蚊埃文德罗伊、特立尼达沙蝇和五裂沙蝇）携带利什曼原虫（利什曼）。在农村（Ny. whitmani：35.2%和 Ev. evandroi：32.4%）和城市地区（Lu. longipalpis：89.8%）中最丰富的物种是利什曼（L.）亚马逊的允许媒介，尤其是 Ny. whitmani，它是皮肤利什曼病病原体的已知媒介。尽管 Lu. longipalpis 是 L.（L.）婴儿的媒介，但在本研究中未检测到该媒介，但已报道其对 L.（L.）亚马逊的传播具有允许性。我们怀疑内脏利什曼病和皮肤利什曼病是由 L.（L.）亚马逊引起的，传播可能是通过 Lu. longipalpis 发生的，至少在城市地区是这样。
