Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz, Bolivia.
Centro de Investigación para la Salud en América Latina (CISeAL), Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador.
Parasit Vectors. 2022 Aug 29;15(1):307. doi: 10.1186/s13071-022-05423-3.
Chagas disease, one of the most important neglected tropical diseases in the countries of Latin America, is considered to be a particularly important public health concern in the Amazon region due to increases in the number of outbreaks of acute Chagas disease and increased local transmission in the last 20 years. However, relative to other countries, in Bolivia there is little information available on its transmission in the Amazon region. The aim of this study was to investigate the infestation of palm trees, the main habitat of Triatominae in the region, in several localities, to evaluate the danger they represent to inhabitants.
Triatominae were collected using live bait traps left overnight in six localities in Pando and Beni Departments, Bolivia. DNA extraction and sequencing were used to establish the Triatominae species (Cytb, 16S and 28S-D2 gene fragments), and the blood meal sources (Cytb fragment). Trypanosoma sp. infection was analyzed by sequencing gene fragments (GPX, GPI, HMCOAR, LAP, PDH and COII) or by mini-exon multiplex PCR.
A total of 325 Rhodnius were captured (97.3% of nymphs) from the 1200 traps placed in 238 palm trees and 32 burrows/ground holes. Sequence analyses on DNA extracted from 114 insects and phylogeny analysis identified two triatomine species: Rhodnius stali (17%) and Rhodnius montenegrensis (equated to Rhodnius robustus II, 83%). These were found in palm trees of the genera Attalea (69%), Astrocaryum (13%), Copernicia (12%), Euterpe (2%) and Acrocomia (1%). The infection rate was around 30% (165 analyzed insects), with 90% of analyzed insects infected by Trypanosoma cruzi (only the TcI discrete typing unit was detected), 3% infected by Trypanosoma rangeli (first time found in Bolivian Triatominae) and 7% infected by mixed T. cruzi (TcI)-T. rangeli. Rhodnius specimens fed on Didelphidae, rodents, gecko and humans.
The results of this study highlight the epidemiological importance of Rhodnius in the Bolivian Amazon region. The huge geographical distribution of Rhodnius and their proximity to the human dwellings, high infection rate and frequent meals on the human population highlight a risk of transmission of Chagas disease in the region.
恰加斯病是拉丁美洲国家中最重要的被忽视热带病之一，由于急性恰加斯病的暴发次数增加以及过去 20 年来当地传播的增加，在亚马逊地区被认为是一个特别重要的公共卫生关注问题。然而，与其他国家相比，玻利维亚在该地区的恰加斯病传播方面的信息较少。本研究的目的是调查在玻利维亚潘多和贝尼两省的六个地点，对棕榈树（该地区三锥虫的主要栖息地）进行侵扰调查，以评估它们对居民的危害。
在玻利维亚潘多和贝尼两省的六个地点，使用过夜的活诱饵陷阱收集三锥虫。使用 DNA 提取和测序来确定三锥虫的种类（Cytb、16S 和 28S-D2 基因片段）和血液来源（Cytb 片段）。通过基因片段（GPX、GPI、HMCOAR、LAP、PDH 和 COII）测序或 mini-exon 多重 PCR 分析感染了克氏锥虫的情况。
从放置在 238 棵棕榈树和 32 个洞穴/地面孔中的 1200 个陷阱中捕获了 325 只 Rhodnius（97.3%的若虫）。从 114 只昆虫中提取的 DNA 序列分析和系统发育分析确定了两种三锥虫：Rhodnius stali（17%）和 Rhodnius montenegrensis（等同于 Rhodnius robustus II，83%）。这些在 Attalea（69%）、Astrocaryum（13%）、Copernicia（12%）、Euterpe（2%）和 Acrocomia（1%）属的棕榈树上被发现。感染率约为 30%（165 只分析昆虫），90%的分析昆虫感染克氏锥虫（仅检测到 TcI 离散型单位），3%感染雷氏锥虫（首次在玻利维亚三锥虫中发现），7%感染混合 T. cruzi（TcI）-T. rangeli。Rhodnius 吸食有袋目动物、啮齿动物、壁虎和人类。
本研究结果突出了 Rhodnius 在玻利维亚亚马逊地区的流行病学重要性。Rhodnius 的巨大地理分布及其接近人类住所、高感染率以及经常取食人类的特点，突显了该地区传播恰加斯病的风险。
