Patterns of house infestation dynamics by non-domiciliated Triatoma dimidiata reveal a spatial gradient of infestation in rural villages and potential insect manipulation by Trypanosoma cruzi.
OBJECTIVE
Chagas disease is a major vector-borne parasitic disease in Latin America, primarily transmitted to humans by triatomine vectors. Non-domiciliated triatomine species such as Triatoma dimidiata in the Yucatan peninsula, Mexico, can transiently invade houses and are emerging as a major challenge to control Trypanosoma cruzi transmission to humans. We analyzed the spatio-temporal spreading of house infestation by T. dimidiata in four rural villages.


METHODS
Triatomines were collected in four rural villages over a 2 years period, and the spatio-temporal patterns of infestation were analyzed.


RESULTS
Triatomines were consistently more abundant at the periphery of villages than in centers, indicating a much higher risk of T. cruzi transmission at the periphery. Male T. dimidiata were found further in the center of the village, while females remained closer to the periphery, suggesting differential dispersal capabilities between sexes, although the timing of dispersal appeared identical. Surprisingly, infected females were consistently collected in houses much further from the surrounding bushes than non-infected females, while the distribution of males was unaffected by their T. cruzi infection status, suggesting an increased dispersal capability in infected females.


CONCLUSIONS
The spatial structure of infestation should be taken into account for the prioritization of vector control activities within villages, and spatially targeted interventions may be explored. A potential vector manipulation by T. cruzi, observed for the first time in triatomines, may favor parasite transmission to new hosts.
Ramirez-Sierra
Maria Jesus
MJ
Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatan, Mexico.
Herrera-Aguilar
Melba
M
Gourbière
Sébastien
S
Dumonteil
Eric
E
D000818:Animals; D014355:Chagas Disease / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D005260:Female; D040362:Geographic Information Systems; D006790:Host-Parasite Interactions; D006798:Housing / Q000706:statistics & numerical data*; D007303:Insect Vectors / Q000254:growth & development* / Q000469:parasitology; D008297:Male; D008800:Mexico / Q000453:epidemiology; D011157:Population Dynamics; D012423:Rural Health / Q000706:statistics & numerical data; D012621:Seasons; D012737:Sex Factors; D013029:Space-Time Clustering; D014224:Triatoma / Q000254:growth & development* / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000302:isolation & purification / Q000502:physiology*