Unknown

Dataset Information

0

Trypanosoma cruzi infection in Triatoma infestans and high levels of human-vector contact across a rural-to-urban gradient in the Argentine Chaco.


ABSTRACT:

Background

Peri-urban and urban settings have recently gained more prominence in studies on vector-borne transmission of Trypanosoma cruzi due to sustained rural-to-urban migrations and reports of urban infestations with triatomines. Prompted by the finding of Triatoma infestans across the rural-to-urban gradient in Avia Terai, an endemic municipality of the Argentine Chaco, we assessed selected components of domestic transmission risk in order to determine its variation across the gradient.

Methods

A baseline vector survey was conducted between October 2015 and March 2016, following which we used multistage random sampling to select a representative sample of T. infestans at the municipal level. We assessed T. cruzi infection and blood-feeding sources of 561 insects collected from 109 houses using kinetoplast DNA-PCR assays and direct enzyme-linked immunosorbent assays, respectively. We stratified triatomines according to their collection site (domestic or peridomestic), and we further categorized peridomestic sites in ecotopes of low- or high-risk for T. cruzi infection.

Results

The overall adjusted prevalence of T. cruzi-infected T. infestans was 1.8% (95% confidence interval [CI] 1.3-2.3) and did not differ between peri-urban (1.7%) and rural (2.2%) environments. No infection was detected in bugs captured in the urban setting; rather, infected triatomines were mainly collected in rural and peri-urban domiciles, occurring in 8% of T. infestans-infested houses. The main blood-feeding sources of domestic and peridomestic triatomines across the gradient were humans and chickens, respectively. The proportion of triatomines that had fed on humans did not differ between peri-urban (62.5%) and rural (65.7%) domiciles, peaking in the few domestic triatomines collected in urban houses and decreasing significantly with an increasing proportion of chicken- and dog- or cat-fed bugs. The relative odds ratio (OR) of having a T. cruzi infection was nearly threefold higher in bugs having a blood meal on humans (OR 3.15), dogs (OR 2.80) or cats (OR: 4.02) in a Firth-penalized multiple logistic model.

Conclusions

Trypanosoma cruzi transmission was likely occurring both in peri-urban and rural houses of Avia Terai. Widespread infestation in a third of urban blocks combined with high levels of human-triatomine contact in the few infested domiciles implies a threat to urban inhabitants. Vector control strategies and surveillance originally conceived for rural areas should be tailored to peri-urban and urban settings in order to achieve sustainable interruption of domestic transmission in the Chaco region.

SUBMITTER: Alvedro A 

PROVIDER: S-EPMC7796388 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

altmetric image

Publications

Trypanosoma cruzi infection in Triatoma infestans and high levels of human-vector contact across a rural-to-urban gradient in the Argentine Chaco.

Alvedro Alejandra A   Gaspe María Sol MS   Milbourn Hannah H   Macchiaverna Natalia Paula NP   Laiño Mariano Alberto MA   Enriquez Gustavo Fabián GF   Gürtler Ricardo Esteban RE   Cardinal Marta Victoria MV  

Parasites & vectors 20210109 1


<h4>Background</h4>Peri-urban and urban settings have recently gained more prominence in studies on vector-borne transmission of Trypanosoma cruzi due to sustained rural-to-urban migrations and reports of urban infestations with triatomines. Prompted by the finding of Triatoma infestans across the rural-to-urban gradient in Avia Terai, an endemic municipality of the Argentine Chaco, we assessed selected components of domestic transmission risk in order to determine its variation across the gradi  ...[more]

Similar Datasets

| S-EPMC9277862 | biostudies-literature
| S-EPMC8401064 | biostudies-literature
| S-EPMC2782367 | biostudies-literature
| S-EPMC4364707 | biostudies-literature
| S-EPMC8777832 | biostudies-literature
| S-EPMC3642171 | biostudies-literature
| S-EPMC6874570 | biostudies-literature
| S-EPMC3623707 | biostudies-literature
| S-EPMC6936860 | biostudies-literature
| S-EPMC9143535 | biostudies-literature