INVESTIGADORES
GURTLER Ricardo Esteban
artículos
Título:
Domestic animal hosts strongly influence human-feeding rates of the Chagas disease vector Triatoma infestans in Argentina
Autor/es:
GURTLER RE; CECERE MC; VAZQUEZ-PROKOPEC GM; CEBALLOS LA; GUREVITZ JM; FERNÁNDEZ MP; KITRON U; COHEN JE
Revista:
PLOS NEGLECTED TROPICAL DISEASES
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2014 p. 2894 - 2894
ISSN:
1935-2735
Resumen:
Background: The host species composition in a household and their relative availability affect the host-feeding choices of
blood-sucking insects and parasite transmission risks. We investigated four hypotheses regarding factors that affect bloodfeeding
rates, proportion of human-fed bugs (human blood index), and daily human-feeding rates of Triatoma infestans, the
main vector of Chagas disease.
Methods: A cross-sectional survey collected triatomines in human sleeping quarters (domiciles) of 49 of 270 rural houses in
northwestern Argentina. We developed an improved way of estimating the human-feeding rate of domestic T. infestans
populations. We fitted generalized linear mixed-effects models to a global model with six explanatory variables (chicken
blood index, dog blood index, bug stage, numbers of human residents, bug abundance, and maximum temperature during
the night preceding bug catch) and three response variables (daily blood-feeding rate, human blood index, and daily
human-feeding rate). Coefficients were estimated via multimodel inference with model averaging.
Findings: Median blood-feeding intervals per late-stage bug were 4.1 days, with large variations among households. The
main bloodmeal sources were humans (68%), chickens (22%), and dogs (9%). Blood-feeding rates decreased with increases
in the chicken blood index. Both the human blood index and daily human-feeding rate decreased substantially with
increasing proportions of chicken- or dog-fed bugs, or the presence of chickens indoors. Improved calculations estimated
the mean daily human-feeding rate per late-stage bug at 0.231 (95% confidence interval, 0.157?0.305).
Conclusions and Significance: Based on the changing availability of chickens in domiciles during spring-summer and the
much larger infectivity of dogs compared with humans, we infer that the net effects of chickens in the presence of
transmission-competent hosts may be more adequately described by zoopotentiation than by zooprophylaxis. Domestic
animals in domiciles profoundly affect the host-feeding choices, human-vector contact rates and parasite transmission
predicted by a model based on these estimates.