Probability of transmission of Chagas disease by Triatoma infestans (Hemiptera: Reduviidae) in an endemic area of Santiago del Estero, Argentina.
The daily probability (P) of transmission of Trypanosoma cruzi to a noninfected human host by an infected Triatoma infestans bug was estimated using field data from a 2-year longitudinal study carried out in a rural settlement of 20 households in Amamá, Santiago del Estero, Argentina. The following information was used for this purpose: the bug density and the proportion of infected bugs; the bug biting rate and the distribution of bites between humans and animals; the age-specific seropositivity to T. cruzi of the human population; and the actual number of new cases of human infection. The 2-year accumulated number of infective contacts per house estimated using a binomial model shows a statistically significant logistic correlation with the observed proportion of new cases per house. An average house where new cases of human infection were registered in the 2-year period had a P value of 0.0012, while an average general house (i.e., with and without new cases) had a P value of 0.0009. The observed range of P is discussed in terms of the chain of factors that affects the individual human risk of acquiring the infection and the possible entomological sampling errors.
Rabinovich
J E
JE
National Institute for the Diagnosis and Investigation of Chagas Disease, Buenos Aires, Argentina.
Wisnivesky-Colli
C
C
Solarz
N D
ND
Gürtler
R E
RE
D000293:Adolescent; D000818:Animals; D001118:Argentina / Q000453:epidemiology; D014355:Chagas Disease / Q000453:epidemiology / Q000635:transmission*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007299:Insect Bites and Stings; D007303:Insect Vectors; D008137:Longitudinal Studies; D008954:Models, Biological; D011156:Population Density; D011336:Probability; D012424:Rural Population; D014224:Triatoma / Q000469:parasitology*