An entomological and seroepidemiological study of the vectorial‐transmission risk of Chagas disease in the coast of northern Chile

Abstract

Four species of triatomines are known from Chile: Triatoma infestans Klug, Mepraia spinolai Porter, M. gajardoi Frías, Henry & González, and M. parapatrica Frías (Hemiptera: Reduviidae), the last three are endemic. The geographical distribution of M. gajardoi includes the coastal areas in the north of Chile between 18° and 21°S, an area with both a resident workforce and summer-season visitors. A study was developed to assess the risk of vectorial transmission of Chagas disease by M. gajardoi in hut settlements on the coast of the Tarapacá Region, in particular in Caleta San Marcos and Caleta Río Seco. The study comprised fingerstick sampling of 95 persons, venous samples from 29 domestic dogs and capture of 52 triatomines, from both fishing coves. The samples were analysed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. The results show that, of the total number of persons studied, 100% were negative for Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae) antibodies, 10.34% of canids were positive for the antibody and 5.8% of M. gajardoi were infected to the PCR technique. The presence of this species in areas close to human settlements constitutes a risk to human populations established on the coast of northern Chile.

Blood-Meal Sources and Trypanosoma cruzi Infection in Coastal and Insular Triatomine Bugs from the Atacama Desert of Chile

“…We showed that T. cruzi-infected M. parapatrica are feeding on humans at these sites, which represents a threat to the human population and a potential risk if these populations are vulnerable due to lack of knowledge of the transmission cycle of Chagas disease and its vectors. Our study increases the knowledge of the less-studied and less-abundant Mepraia species and supports the concern about Chagas disease risk for human populations in the north-central coast of Chile [14].…”

“…In the same island T. cruzi-infected rodents (6.1% infection frequency) and triatomine bugs (20.3% infection frequency) have been reported [13]. Other studies have reported M. gajardoi populations associated with fishers' dwellings and T. cruzi infection in dogs living nearby, warning about the epidemiological risk of these triatomine bugs due to the proximity of kissing bugs to human settlements, dogs acting as a reservoir and the potential invasion of triatomine bugs in fishers' coves [14,15]. Pan de Azúcar National Park (PANP hereafter) is a protected area in northern Chile where fishers' dwellings and tourist activities occur close to M. parapatrica populations.…”

Potential impact of climate change on the geographical distribution of two wild vectors of Chagas disease in Chile: Mepraia spinolai and Mepraia gajardoi

“…The sylvatic M. spinolai is very abundant in stone quarries of periurban zones [7] where it feeds on wild rodents, goats, dogs, cats, rabbits and humans [8, 9], and several home invasion complaints are notified to the authorities every year (data requested from http://www.portaltransparencia.cl). Mepraia gajardoi is abundant near seaweed collector settlements, where it preferably feeds on sea birds, marine mammals, lizards, dogs, cats and humans [10, 11]. These situations are epidemiologically relevant, especially considering that the prevalence of T. cruzi in M. spinolai populations can reach up to 76.1% [12] and 27.0% for M. gajardoi [13].…”

Trypanosomatid Infections among Vertebrates of Chile: A Systematic Review

“…Several studies have assessed T. cruzi infection in C. l. familiaris and F. catus , which have shown a high variability, mainly depending on the diagnostic technique and, to a lesser extent, on the location of the populations prospected. The infection prevalence in C. l. familiaris ranges from 0 to 34.8% when assessed by optical microscopy, XD, and serology (IHA, IIF and enzyme-linked immunosorbent assay; ELISA) [ 15 , 16 , 29 , 36 , 37 , 39 , 40 , 41 , 42 , 43 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 70 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ], while few studies using cPCR, real-time PCR and nested PCR showed infection prevalence from 17.1 to 35.2% [ 19 , 86 , 87 ]. The infection prevalence in F. catus ranges from 0 to 23.4% when assessed by optical microscopy, XD, and serology (IHA) [ 15 , 16 , 29 , 36 , 37 , 39 ,…”