Chagas disease vector control through different intervention modalities in endemic localities of Paraguay.
In a field study carried out in three rural communities in Paraguay in a zone endemic for Chagas disease, we implemented three different vector control interventions--spraying, housing improvement, and a combination of spraying plus housing improvement--which effectively reduced the triatomine infestation. The reduction of triatomine infestation was 100% (47/47) in the combined intervention community, whereas in the community where housing improvement was carried out it was 96.4% (53/55). In the community where fumigation alone was used, the impact was 97.6% (40/41) in terms of domiciliary infestation. In all the houses where an intervention was made, an 18-month follow-up showed reinfestation rates of less than 10%. A serological survey of the population in the pre- and post-intervention periods revealed a shift in positive cases towards older age groups, but no significant differences were observed. The rate of seroconversion was 1.3% (three new cases) in the community with housing improvement only, but none of these cases could have resulted from vector transmission. The most cost-effective intervention was insecticide spraying, which during a 21-month follow-up period had a high impact on triatomine infestation and cost US$ 29 per house as opposed to US$ 700 per house for housing improvement.
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D014355:Chagas Disease / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control* / Q000635:transmission; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D019353:Endemic Diseases / Q000517:prevention & control* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D007300:Insect Control / Q000191:economics / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010239:Paraguay / Q000453:epidemiology; D015397:Program Evaluation; D012423:Rural Health; D016036:Seroepidemiologic Studies; D014224:Triatoma / Q000469:parasitology*