Vector distribution of Chagas Disease in "non-endemic" countries: the possibility of vector transmission outside Latin America

With increasing reports of Trypanosoma cruzi infection amongst immigrants from Latin America, and some cases of onward transmission by blood transfusion, organ transplant, and transplacental cases, there is also concern about the possibility of vector-borne transmission of T. cruzi in the so-called 'non-endemic' countries. The primary insect vectors of T. cruzi - causative agent of Chagas disease - are blood-sucking Hemiptera of the subfamily Triatominae (family Reduviidae). These are mainly of Latin American origin, although several species of Triatoma also occur in the USA where autochthonous vector-borne transmission has already been reported. Triatoma rubrofasciata - which has probably derived from a North American species of Triatoma - is reported from port areas throughout the tropics and subtropics, and derivative forms are now widespread in parts of India and Southeast Asia. However, these species generally have little contact with humans, and currently seem unlikely to play an important epidemiological role. T. cruzi can infect a range of other arthropods but the likelihood of transmission by this means seems extremely remote. The greatest risk seems to be posed by accidental transport of domestic Latin American species of Triatominae to other regions, and there is good evidence to suggest that such transport is possible (for example amongst the baggage of airline passengers) and that some of these domestic species could survive and reproduce even in temperate regions of Europe, USA, and other continents.