Distribution, genetic characteristics and public health implications of Triatoma rubrofasciata, the vector of Chagas disease in Guangxi, China

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 Different methods were used to elucidate the distribution of triatomines in Guangxi including consultations with county-level Center for Disease Prevention and Control staff and village doctors, the distribution of educational 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 triatomines were identified under light microscopy. The mitochondrial 16S rRNA, cytochrome b (cytb) genes and nuclear 28S rRNA gene were amplified, sequenced and used in phylogenetic analyses. Results A total of 305 triatomines were captured from 54 different sites in 13 cities in Guangxi. All collected bugs were identified 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 common, 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 different regions exhibit a high similarity, with no geographical differences. The phylogenetic tree based on the 16S rRNA and cytb genes showed that T. rubrofasciata sequences from different regions and continents were in the same cluster, indicating no differentiation among different 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. rubrofasciata and to strengthen the monitoring of imported Trypanosoma cruzi in China. The 16S rRNA, 28S rRNA and cytb sequence analyses of T. rubrofasciata from different regions and continents suggested that T. rubrofasciata populations exhibit high similarity, and the clustering in the phylogenetic analyses indicates that T. rubrofasciata has a close ancestor originating in the Americas.

Chagas Disease — An Underestimated Global Public Health Challenge

“…Though China is a non-endemic country and no CD cases have been reported yet, we have to improve our capacity in the surveillance of potential risks of the disease transmission, since the vector exists in China. As shown in results from previous surveys, one of the transmission vectors, Triatoma rubrofasciata , has been found in at least five provinces in southern China ( 13 - 14 ). By considering the high mobility between China and the world, CD will be possibly introduced in China.…”

Distribution of Triatomines, the Vector of Chagas Disease — Southern China, 2016−2018

“…The widespread distribution of T. rubrofasciata found in our study exceeded the sporadic existing records found in museums and in the literature. For example, in Guangxi, T. rubrofasciata was captured in 13 out of 14 prefecture-level cities; Guilin City was the only exception ( 7 ). For this report, this insect presented dispersion favored by interactions with residential settlements and human activities ( 8 ).…”

Exposure to Trypanosoma parasites induces changes in the microbiome of the Chagas disease vector Rhodnius prolixus

“…Most of them live in rural regions of Latin America, but due to emigration of population, Chagas disease has increasingly spread to urban areas and non-endemic countries with non-vectorial transmission routes [13]. In addition, some triatomine vectors, especially the cosmopolitan Triatoma rubrofasciata, also show a considerable potential for further geographical expansion [14][15][16]. Unlike in other blood-sucking insects, T. cruzi is not transmitted by the bite but by infectious faeces which are accidentally rubbed into the bite wound.…”