Shi et al. Parasites Vectors (2020) 13:33 https://doi.org/10.1186/s13071-020-3903-z Parasites & Vectors RESEARCH Open Access Distribution, genetic characteristics and public health implications of Triatoma rubrofasciata, the vector of Chagas disease in Guangxi, China Yunliang Shi1, Yaobao Wei1, Xiangyang Feng1, Jianfeng Liu2, Zhihua Jiang1, Fangqi Ou1, Haiyan Wei1, Guoli Lv1, Xiaoling Wan1, Ziyue Wang3 and Yichao Yang1* Abstract Background: Triatomines are natural vectors of Chagas disease and are mainly prevalent in the Americas. In China, previous data from decades ago showed that there were two species of triatomine bugs, Triatoma rubrofasciata and T. sinica. However, the distribution, genetic characteristics and public health implications of triatomines in China are still relatively unknown. In order to gain knowledge on the distribution, genetic characteristics and public health implications of the triatomines in Guangxi, China, an entomological-epidemiological study and genetic research was conducted. Methods: Diferent methods were used to elucidate the distribution of triatomines in Guangxi including consulta- tions with county-level Center for Disease Prevention and Control staf and village doctors, the distribution of educa- tional material on triatomines though the internet and social media apps such as Wechat and QQ, and conducting manual inspections and light trapping to collect triatomines. The morphological characteristics of the collected tri- atomines were identifed under light microscopy. The mitochondrial 16S rRNA, cytochrome b (cytb) genes and nuclear 28S rRNA gene were amplifed, sequenced and used in phylogenetic analyses. Results: A total of 305 triatomines were captured from 54 diferent sites in 13 cities in Guangxi. All collected bugs were identifed as T. rubrofasciata based on morphology. Most triatomine collection sites were around or inside houses. Four triatomines bite cases were observed during the investigation indicating that triatomine bites are com- mon, the bites can cause serious anaphylaxis and skin papules and urticaria, suggesting a systemic skin response. The 16S rRNA, 28S rRNA and cytb sequence analyses of T. rubrofasciata from Guangxi and other countries showed that T. rubrofasciata sequences from diferent regions exhibit a high similarity, with no geographical diferences. The phylo- genetic tree based on the 16S rRNA and cytb genes showed that T. rubrofasciata sequences from diferent regions and continents were in the same cluster, indicating no diferentiation among diferent geographical populations. Conclusions: Our study showed that T. rubrofasciata is widely distributed in Guangxi and that people are commonly bitten by this insect in some regions. This highlights the need to enhance surveillance for and control of T. rubrofas- ciata and to strengthen the monitoring of imported Trypanosoma cruzi in China. The 16S rRNA, 28S rRNA and cytb *Correspondence: [email protected] 1 Institute of Parasitic Disease Prevention and Control, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning 530028, China Full list of author information is available at the end of the article © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creat iveco mmons .org/licen ses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/publi cdoma in/ zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Shi et al. Parasites Vectors (2020) 13:33 Page 2 of 11 sequence analyses of T. rubrofasciata from diferent regions and continents suggested that T. rubrofasciata popula- tions exhibit high similarity, and the clustering in the phylogenetic analyses indicates that T. rubrofasciata has a close ancestor originating in the Americas. Keywords: Triatoma rubrofasciata, Guangxi, Distribution, Genetic characteristics Background or aware of the consequences. Several publications rang- Chagas disease, or American trypanosomiasis, is one of ing from the characterization of the number of chromo- the 10 most seriously neglected tropical diseases [1] and somes [30] to the description of the genome [31] and its currently afects 10 million people worldwide [2]. Tere phylogenetic relationships [32] have contributed to the is no vaccine or efective cure once the symptoms of genetic, taxonomic and evolutionary knowledge of T. the chronic disease have manifested. Chagas disease is rubrofasciata. However, little is known about the actual considered limited to the Americas; however, in recent distribution of this vector in China. Tus, we conducted decades, it has become a global health issue [3]. Due to an entomological-epidemiological study and genetic the growing rate of immigrants unaware of their own research in Guangxi, China. infection status [4], the disease can potentially spread to non-endemic countries. Moreover, Trypanosoma cruzi Methods Chagas, 1909 (Kinetoplastida, Trypanosomatidae) can be Triatomines and triatomine bite investigations transmitted by blood transfusion and organ transplanta- Triatomine collection in the feld was carried out from tion. With increasing transcontinental exchanges, Cha- July 2016 to October 2018 in Guangxi, China. First, we gas disease is no longer restricted to the Americas [5, 6]. asked the county level Center for Disease Prevention Currently, it has been diagnosed in several non-endemic and Control staf and village doctors about the presence countries, such as New Zealand, Australia, Japan and of T. rubrofasciata in its suspected distribution areas Europe [7–9]. and showed them pictures of triatomines. Te feld- Chagas disease is transmitted mainly by triatomine work involved inspection of old houses (houses made of bugs (kissing bugs) [10] belonging to 18 genera and 154 clay), tree cavities, wood and rock piles, chicken coops species worldwide [11–16]. Triatoma rubrofasciata (De and dog kennels. Additionally, light traps were used to Geer, 1773) is the only species with a worldwide distribu- collect triatomines. Te light installation followed the tion [17]. It is mostly found in Asia, Oceania, Africa and method by Castro et al. [33] and included a mobile elec- Central America. It is a common vector of Trypanosoma tric power pack and approximately a 1.8 × 2.2 m verti- conorhini (Donovan) that infects Rattus rattus [18, 19]. T. cal aluminium frame with a white sheet. Te frame was rubrofasciata is also occasionally found naturally infected kept erect with guide ropes. On both sides of the frame, by T. cruzi [20, 21]. Additionally, T. rubrofasciata bites two 125 W and 250 W mercury vapor bulbs (HPL) were can cause dermatitis, anaphylactic shock, and even death suspended with external ballasts. Te light trap was run [22, 23]. from sunset until midnight and the insects on the sheet In China, very few records have indicated that T. rubro- were checked every hour. Geographical coordinates of fasciata exists in southern China, such as in Guangxi the location from where the specimens were caught were Zhuang Autonomous Region, Guangdong and Fujian recorded with a handheld GPS unit (UniStrong, Beijing, provinces [24–26]. Furthermore, the peridomestic pres- China) for each site. To obtain more information on tri- ence of T. rubrofasciata was reported to the northeast atomine distribution, we disseminated electronic post- of Hanoi, extending across the frontier well into south- ers and leafets about the triatomine bugs on the internet ern China [27]. However, there have been few studies on and social media Apps such as Wechat. Te electronic T. rubrofasciata over the decades in China, and a very poster and leafets were also distributed to the staf of the limited amount of information about its distribution County and City Disease Prevention and Control units. has been published. Two blood-sucking triatomines, People who found the bugs sent photos with locations. T. rubrofasciata and T. sinica Hsiao, 1965, have been We identifed the species of the triatomine based on the reported in China over the past fve decades [24]. Nine photos and went to the location to collect the specimen. cases of T. rubrofasciata invading houses and biting peo- In the locations where triatomines were found, we inter- ple, resulting in anaphylactic shock or death, have been viewed the local people about how often they get bitten reported in China [23, 28, 29]. However, blood-sucking by triatomines. Information from each individual who triatomines have received limited attention for decades. had been bitten by triatomines was collected, including People are not sufciently concerned about this insect Shi et al. Parasites Vectors (2020) 13:33 Page 3 of 11 personal information, symptomatic descriptions, treat- including juvenile and adult bugs (see Additional