Sylvatic triatominae: a new challenge in vector control transmission

Abstract

infestans, T. dimidiata and T. brasiliensis).The other species are less efficient vectors and are more limited in their geographic distribution, except for P. megistus (WHO 2007).The T. cruzi transmission rate is influenced by many factors, including insect density, the reproductive frequency of T. cruzi, the possibility of insect interactions with humans or other important reservoirs, their longevity, human and reservoir susceptibility to infection, vector and reservoir distribution related to human populations, vector and reservoir infection rates and the duration of parasitaemia (Schofield 1994). Vectorial controlDifferent from autochthonous vector species, domiciliated species such as T. infestans in the Southern Cone and R. prolixus in Central America are considered to be introduced species that have become adapted to human habitat due to their passive transport by human migration over time. They show a high degree of susceptibility to pyrethroid insecticides.When it is known that vectors have become domiciliated and are actively responsible for transmission, spraying residual action insecticides is not questioned, given that the insecticides represent a means of immediate control to alleviate the suffering of inhabitants who have been in contact with vector insects within the last 6-8 months. Residual action insecticides are not permanent. After the product's residual action time has passed, a second spraying cycle is necessary. This, in turn, is temporary, and it is possible for the house to become reinfested once again. This is when control programmes must establish an entomological surveillance component to impede re-infestation efforts, especially by adventitious sylvatic species.It is clear that using a particular control method does not exclude using another one. Chemical control must complement other efforts such as improving rural housing, managing the environment and ordering the peridomiciliary area where autochthonous vector insect species are frequently found.A series of standards and stages in the technical and operational levels must be followed consistently for the control programme to be effective. To control Chagas disease, it is necessary to prevent parasite transmission by its two main mechanisms (vectorial and transfusional) and to complement this prevention with a secondary level of prevention in terms of medical and social attention for infected people. The key elements to such a programme, which has been proven successful, have been previously described by several authors (Schofield &

Absence of domestic triatomine colonies in an area of the coastal region of Ecuador where Chagas disease is endemic

“…However, the risk of T. cruzi transmission will continue afterwards due to the possibility of reinfestation by sylvatic triatomine species, such as R. ecuadoriensis (Guhl et al 2009). Therefore, additional studies should be conducted in this region to better understand the distribution and ecology of endemic triatomine species and the implementation of an integral and coordinated insect control program that adds triatomine infestation surveillance to the existing mosquito control activities.…”

Comportamiento alimenticio de Rhodnius robustus Larrousse, 1927 (Hemiptera, Reduviidae) en condiciones de laboratorio

“…Según Dujardin, et al, y Guhl, et al, los estudios sobre competencia vectorial de los vectores secundarios son prioritarios en los países endémicos para la enfermedad de Chagas (12,13).…”

Sylvatic foci of the Chagas disease vector Triatoma infestans in Chile: description of a new focus and challenges for control programs

“…Sylvatic triatomines may occasionally invade human residences, acting as founders of new colonies (Fitzpatrick et al 2008). Hence, it is necessary to study the ecology and behavior of their populations to understand the domiciliation process and generate new strategies for their control (Beard et al 2002, Guhl et al 2009, Moncayo & Silveira 2009). …”