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Volume 20, Number 12—December 2014

Residual Infestation and Recolonization during Urban Triatoma infestans Bug Control Campaign, Peru1

Corentin M. BarbuComments to Author , Alison M. Buttenheim, Maria-Luz Hancco Pumahuanca, Javier E. Quintanilla Calderón, Renzo Salazar, Malwina Carrión, Andy Catacora Rospigliossi, Fernando S. Malaga Chavez, Karina Oppe Alvarez, Juan Cornejo del Carpio, César Náquira, and Michael Z. Levy
Author affiliations: University of Pennsylvania, Philadelphia, Pennsylvania, USA (C.M. Barbu, A.M. Buttenheim, M.Z. Levy); Universidad Peruana Cayetano Heredia, Arequipa, Peru (M.-L. Hancco Pumahuanca, J.E. Quintanilla Calderón, R. Salazar, M. Carrión, C. Náquira); Red de Salud Aequipa Caylloma, Arequipa (A. Catacora Rospigliossi); Dirección Regional del Ministerio de Salud, Arequipa (F.S. Malaga Chavez, K. Oppe Alvarez, J. Cornejo del Carpio)

Main Article

Table 3

Household level model of observation, initial infestation, treatment, and residual infestation during treatment phase of a Chagas disease vector campaign, Arequipa, Peru, 2003–2011*

Treatment received Observed infestation Estimated initial prevalence Estimated residual prevalence
I and II pI/II = nI/II/TI//II rI/II = pI/II × (1 – c)2

I only
OI+IIØ = nI × s
pI = nI/TI
rI = pI × (1 – c)
II only
OIØII+ = nII × s
rII = pII × (1 – c)
None Not observed pØ = pII rØ = pØ

*Upper case letters refer to observed quantities. Lower case letters refer to estimated quantities. OIxIIy, number of infested households observed in the first (Ix) and second (IIy) step of the treatment phase, with x and y taking the following values: , no treatment and infestation could not be observed; +, treated and observed infested; –, treated and observed noninfested. For nz, pz, Tz, and rz, the subscript z corresponds to the participation in treatments: I, only first; II, only second; I/II, both; nz, estimated number of infested households; pz, estimated initial prevalence of infestation; Tz, total number of households; rz, estimated residual prevalence of infestation post treatment phase; s, sensitivity of technicians performing treatment to household infestation; c, probability of clearing infestation when treated. Further details and the solved system of equations have been provided by the authors (

Main Article

1The authors have provided a Spanish version of this article online (

Page created: November 18, 2014
Page updated: November 18, 2014
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