Back to search
Publication

Urbanisation, risk stratification and house infestation with a major vector of Chagas disease in an endemic municipality of the Argentine Chaco

Abstract
Background
The occurrence of the major vectors of Chagas disease has historically been linked to poor rural housing, but urban or peri-urban infestations are increasingly being reported. We evaluated a simple risk index to detect houses infested with Triatoma infestans and tested whether house infestation and vector abundance increased across the urban-to-rural gradient in Avia Terai, an endemic municipality of the Argentine Chaco; whether the association between infestation and selected ecological determinants varied across the gradient; and whether urban and peri-urban infestations were associated with population settlement history.

Methods
We conducted a screening survey of house infestation in 2296 urban, peri-urban and rural dwellings to identify high-risk houses based on a simple index, and then searched for triatomines in all high-risk houses and in a systematic sample of low-risk houses.

Results
The risk index had maximum sensitivity and negative predictive value, and low specificity. The combined number of infested houses in peri-urban and urban areas equalled that in rural areas. House infestation prevalence was 4.5%, 22.7% and 42.4% across the gradient, and paralleled the increasing trend in the frequency of domestic animals and peridomestic structures. Multiple logistic regression analysis showed that house infestation was positively and significantly associated with the availability of poultry and bug refuges in walls, and was negatively associated with domestic insecticide use. Several pieces of evidence, including absence of spatial aggregation of house infestation, support that T. infestans has been a long-established occupant of urban, peri-urban and rural settings in Avia Terai.

Conclusions
An integrated vector management strategy targeting chicken coops and good husbandry practices may provide more cost-effective returns to insecticide-based vector elimination efforts.

More information

Type
Journal Article
Author
Gaspe MS
Fernández MDP
Cardinal MV
Enriquez GF
Rodríguez-Planes LI
Macchiaverna NP
Gürtler RE
Year of Publication
2020
Journal
Parasites & Vectors
Volume
13
Issue
1
Language
eng
ISSN Number
1756-3305
DOI
10.1186/s13071-020-04182-3
Publication Language
eng