Domestic vectors of Chagas' disease in three rural communities of Nicaragua

Abstract

A triatomine survey was conducted in three rural settlements of Nicaragua (Santa Rosa, Quebrada Honda and Poneloya) where Chagas' disease is endemic, to determine rates of house infestation, evaluate the housing condition and to asess the performance of the María sensor box in detection of domestic vectors. A total of 184 households were selected and vectors were sought by the methods of timed manual capture and by sensor boxes. The sole vectors species found in this study was Triatoma dimidiata. Of the examined bugs 50, 60 and 33%, in the respective communities, were infected with T. cruzi. The rates of house infestation as determined by manual capture and sensor boxes were respectively, 48.3% and 54.2% in Santa Rosa, 29.8% and 51.2% in Quebrada Honda and in Poneloya 3.8 and 5.9% with significant difference between the methods in Quebrada Honda. When compared with the manual capture, the Maria sensor box detected vectors in 71.4% of positive houses in two of the communities but also was able to detect bugs in 39.3% and 41.1% of houses where manual capture had been negative. Housing condition was evaluated according to three structural parameters, in this way, in the first community 79.2% of houses were classified as bad, 20.8% as regular; in the second one 42.5% were bad and 57.5% regular, whereas in the third 62.5% of the houses were regular. Rates of infestation did not differ greatly between the different housing conditions. Our results show that the sensor box is as efficient as manual capture and could be implemented in our country.

Community Participation in Chagas Disease Vector Surveillance: Systematic Review

“…As defined here, they differ from the traditional, ‘active’ surveillance approach in that control programme agents do not search the whole residence to determine whether it is infested; instead, they rapidly check for bugs (or their traces) in a ‘detection device’. Table 3 summarises the main results of major comparative studies [20] – [22] , [26] – [28] , [130] , [132] , [134] – [140] . In general, the sensitivity of vector-detection devices does not seem to be superior to that of active searches, but (i) both methods appear to complement each other, with only one of them revealing infestation in many instances (see also ref.…”

Indicadores de infestación, colonización e infección de Triatoma dimidiata (Latreille) (Hemiptera: Reduviidae) en Campeche, México

“…En Oaxaca se determinó un índice de infección de 3.7% (Ramsey et al 2000). Existen discrepancias en el índice de infección reportado para tres localidades de Nicaragua, en donde se empleo la técnica de observación por microscopio ocular (búsqueda morfológica de T. cruzi), el índice de infección natural fue de 52.6 % (Palma-Guzmán et al 1996). Se piensa que el resultado es alto debido a la baja sensibilidad de la técnica, donde el grado de error es mayor, comparado con los métodos moleculares usados en este estudio.…”

Community-Based Sampling Methods for Surveillance of the Chagas Disease Vector,Triatoma dimidiata(Hemiptera: Reduviidae: Triatominae)

“…Houses are considered positive if, after a set time period, the sensor is found to contain any evidence of bugs or bug activity (i.e., feces, exuviae, eggs, and dead or alive nymphs or adults). Sensor boxes have been evaluated for use with several triatomine species: T. dimidiata (Palma-Guzmán et al 1996), T. infestans (SchoÞeld 1978Pinchin et al 1981;Wisnivesky-Colli et al 1987;Chuit et al 1992;Gü rtler et al 1995, 1999), R. prolixus (Gó mez-Nú ñ ez 1965, Oliveira Filho 1996, Rhodnius ecuadoriensis ((Lent & Leó n) (Cuba Cuba et al 2003), Triatoma sordida Stål (Forattini et al 1973, Dias et al 2005, and Panstrongylus megistus Burmeister (Piesman and Sherlock 1984). Although paper sheets do not intercept bugs, they work in much the same way, collecting evidence of recent triatomine activity.…”