Triatomid Bugs

Triatomid bugs (also known as ‘cone nose’, ‘assassin' or 'kissing bugs’) are large insects belonging to the family Reduviidae, within the order Hemiptera.

In South America there are three genera (Rhodnius,Triatoma and Panstrongylus) belonging to the sub-family Triatominae which contain species that are important vectors of the protozoan parasite Trypanosoma cruzi, a pathogen that causes Chagas disease (American trypanosomiasis). All three of these genera are widely distributed in the Americas from Mexico to Argentina. The most important vector species are Triatoma infestans, T. dimidiata, T. brasiliensis, T. maculata, T. sordida, Rhodnius prolixus, R. neglectus, R. pallescens and Panstronglyus megistus. These bugs have evolved from living in the burrows or nests of wild animals and now commonly infest cracks and crevices of poorly constructed houses and outbuildings (eg. mud, adobe or thatch houses), wood piles and tiled roofs. Some of these species maintain sylvatic colonies (eg. T. dimidiata) and this presents greater challenges for their control due to the recolonization of treated houses.

This disease, which affects more than 10 million people, is one of the biggest infectious diseases in South America. Whilst it can cause symptoms soon after infection (in about 1 percent of cases) many people do not become ill until later when the chronic infection causes serious damage to the heart or intestinal tract. There is no effective cure once the disease has progressed to these latter stages.

 

Approximately 50,000 people die from Chagas disease each year.

The zoonotic nature of Chagas disease presents a significant challenge for its control and eradication. Vector control and the improvement of housing structures to eliminate harbourage sites are therefore extremely important methods to reduce the transmission of the disease.

Pyrethroids have traditionally been the insecticides of choice because of their low toxicity to humans, their high effectiveness, and their repellent action (which can aid in bringing the insects out of their harbourages and into contact with residual spray deposits). However, resistance to pyrethroids has been detected in some Triatomid populations (eg. in Bolivia) and compounds with alternative modes of action (e.g. bendiocarb) are now also important in the fight against this disease.

> Control of Chagas Disease - Report of the WHO Expert Committee (PDF)