Distribution of Triatomines, the Vector of Chagas Disease - Southern China, 2016-2018.
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ABSTRACT:
SUBMITTER: Liu Q
PROVIDER: S-EPMC8392960 | biostudies-literature | 2020 Aug
REPOSITORIES: biostudies-literature
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Distribution of Triatomines, the Vector of Chagas Disease - Southern China, 2016-2018.
Liu Qin Q Wu Fangwei F Shi Yunliang Y Lu Wencheng W Xie Hanguo H Guo Yunhai Y Zhu Dan D Li Yuanyuan Y Zhang Yi Y Zhou Xiao-Nong XN
China CDC weekly 20200801 33
<b>What is already known on this topic?</b> Triatomines, also known as kissing bugs, are widespread vectors for Chagas disease which affects 6-8 million people worldwide. Two species of triatomines have been previously reported in China. <b>What is added by this report?</b> This study showed data from the first investigation of triatomine distribution in China. <i>Triatoma rubrofasciata</i> and a novel species of triatomine in 170 habitats in 30 cities in southern China were recorded in this inv ...[more]
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Project description:IntroductionUpdating the distribution and natural infection status of triatomine bugs is critical for planning, prioritizing, and implementing strategies to control Chagas disease (CD), especially after vector reduction programs. After carrying out a control program, the Department of Boyaca contains the highest number of Colombian municipalities certified by PAHO to be free of intradomiciliary transmission of Trypanosoma cruzi by Rhodnius prolixus. The present work describes the spatial distribution, natural infection (NI), and molecular characterization of T. cruzi in synanthropic triatomines from the Department of Boyaca in 2017 and 2018.Materials and methodsAn entomological survey was conducted in 52 municipalities in Boyaca known to have had previous infestations of triatomine bugs. Insects were collected through active searches carried out by technical personnel from the Secretary of Health and community members using Triatomine Collection Stations (PITs-acronym in Spanish). For evaluation of natural infection, triatomines were identified morphologically and grouped in pools of one to five individuals of the same species collected in the same household. DNA derived from the feces of each pool of insects was analyzed by PCR for the presence of T. cruzi using primers flanking the satellite DNA of the parasite. SL-IR primers were used to differentiate TCI from the other DTUs and to identify different genotypes. The distribution of the collected triatomines was analyzed to determine any vector hotspots using spatial recreation.ResultsA total of 670 triatomine bugs was collected, belonging to five species: Triatoma dimidiata (73.2%), Triatoma venosa (16.7%), Panstrongylus geniculatus (5.7%), Rhodnius prolixus (4.4%), and Panstrongylus rufotuberculatus (0.4%), from 29 of the 52 municipalities. In total, 71.6% of the bugs were collected within houses (intradomiciliary) and the rest around the houses (peridomiciliary). Triatoma dimidiata was the most widely distributed species and had the highest natural infection index (37.8%), followed by T. venosa and P. geniculatus. TcI was the only DTU found, with the TcI Dom genotype identified in 80% of positive samples and TcI sylvatic in the other insects. Spatial analysis showed clusters of T. dimidiata and T. venosa in the northeast and southwest regions of Boyaca.ConclusionsAfter some municipalities were certified free of natural transmission within houses (intradomiciliary transmission) of T. cruzi by R. prolixus, T. dimidiata has become the most prevalent vector present, and represents a significant risk of resurgent CD transmission. However, T. venosa, P. geniculatus, and P. rufotuberculatus also contribute to the increased risk of transmission. The presence of residual R. prolixus may undo the successes achieved through vector elimination programs. The molecular and spatial analysis used here allows us to identify areas with an ongoing threat of parasite transmission and improve entomological surveillance strategies.
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