Intrusive versus domiciliated triatomines and the challenge of adapting vector control practices against Chagas disease

Abstract

Chagas disease prevention remains mostly based on triatomine vector control to reduce or eliminate house infestation with these bugs. The level of adaptation of triatomines to human housing is a key part of vector competence and needs to be precisely evaluated to allow for the design of effective vector control strategies. In this review, we examine how the domiciliation/intrusion level of different triatomine species/populations has been defined and measured and discuss how these concepts may be improved for a better understanding of their ecology and evolution, as well as for the design of more effective control strategies against a large variety of triatomine species. We suggest that a major limitation of current criteria for classifying triatomines into sylvatic, intrusive, domiciliary and domestic species is that these are essentially qualitative and do not rely on quantitative variables measuring population sustainability and fitness in their different habitats. However, such assessments may be derived from further analysis and modelling of field data. Such approaches can shed new light on the domiciliation process of triatomines and may represent a key tool for decision-making and the design of vector control interventions.

Diversity of Triatominae (Hemiptera: Reduviidae) in Santander, Colombia: Epidemiological implications

“…Dicho comportamiento involucra especies selváticas, cuyos adultos incursionan en las viviendas atraídos por la luz o llegan transportados de forma pasiva, pues no se ha encontrado evidencia de colonización (huevos, exuvias, ninfas) (14). Los reportes del lugar de captura de esta especie mencionan la casa "elba" (lugar donde se asolean el cacao y el café, la cual tiene techo corredizo), los bombillos y las paredes.…”

“…Los términos "domiciliado" y "no domiciliado" describen el tipo de infestación de los triatominos en la vivienda humana; existen varias categorías para definirla, con niveles intermedios entre ellas (13)(14)(15)(16). En este artículo nos acogeremos a la clasificación con la cual se describen los siguientes hábitos de las especies y poblaciones de triatominos: selváticos, intrusos, domiciliados y domésticos (15).…”

Effectiveness of Large-Scale Chagas Disease Vector Control Program in Nicaragua by Residual Insecticide Spraying Against Triatoma dimidiata

“…In addition, capacity of reinfestation may differ widely among subgroups of T. dimidiata. 10,34 Given such complex mechanisms, the effective control of reinfestation is difficult without understanding the pattern of reinfestation of T. dimidiata in each local setting.…”

“…Its level of adaptation to human dwellings seems to vary widely among regions, from non-domiciled populations in the Yucatan Peninsula and Belize to highly domestic populations in Guatemala. 10 In locations where domestic populations of T. dimidiata are predominant, house infestation by this vector is strongly associated with poor housing conditions and the presence of animals in sleeping areas of the dwelling.…”

A motorized vehicle-mounted sprayer as a new tool for Chagas disease vector control

“…Screening of blood donors and vector control actions dramatically reduced the human prevalence of T. cruzi infection and the population at risk. In the absence of an effective vaccine, residual insecticide spraying still is the main or only tool used to suppress domestic populations of triatomines and remains the most cost-effective strategy 8,9 . The protocols and methodologies for vector control and evaluation were standardized in the 1960s 10 .…”