Chagas disease: assessing the existence of a threshold for bug infestation rate.
To examine the existence of a possible threshold for the domestic infestation rate of Triatoma dimidiata, below which transmission becomes unlikely, a census was conducted in 59 Chagas disease endemic communities of El Salvador and Honduras. Entomological and serological tests were conducted targeting 4,083 households and 6,324 children between 6 months and 15 years of age. The overall domestic infestation rate of Triatoma dimidiata and seroprevalence among children were 12.9% and 0.49%, respectively. Communities with a domestic infestation rate at 8% or less consistently showed a seroprevalence of 0%. In communities with a domestic infestation rate above 8%, there was a wide range in seroprevalence. A domestic infestation rate of 8% could serve as the possible threshold below which transmission would become unlikely. The implementation of an 8% threshold for determining needs for universal insecticide spraying would lead to a 21% reduction in spraying-related costs.
Human Development Department, Japan International Cooperation Agency (JICA), Tokyo, Japan. aiga.hirotsugu@jica.go.jp
Hirotsugu
H
Aiga
Emi
E
Sasagawa
Ken
K
Hashimoto
Jiro
J
Nakamura
Concepción
C
Zúniga
José Eduardo Romero
JE
Chévez
Hector Manuel Ramos
HM
Hernández
Jun
J
Nakagawa
Yuichiro
Y
Tabaru
D000293:Adolescent; D000818:Animals; D014355:Chagas Disease / Q000453:epidemiology* / Q000635:transmission*; D002648:Child; D002675:Child, Preschool; D004478:Ectoparasitic Infestations / Q000453:epidemiology* / Q000517:prevention & control*; D004544:El Salvador / Q000453:epidemiology; D006721:Honduras / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007300:Insect Control / Q000379:methods; D007303:Insect Vectors; D007306:Insecticides; D016036:Seroepidemiologic Studies; D014224:Triatoma / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000302:isolation & purification / Q000472:pathogenicity
D007306:Insecticides