Geographic distribution of Triatoma dimidiata and transmission dynamics of Trypanosoma cruzi in the Yucatan peninsula of Mexico.

Abstract

Abstract. Chagas disease represents a major public health concern in most of Latin America, and its control is currently based on vector control and blood bank screening. We investigated the geographic distribution and seasonal variations in triatomine populations in the Yucatan peninsula of Mexico to obtain entomologic data for the optimization of potential control programs. We collected domiciliated and peri-domiciliated Triatoma dimidiata from 115 houses in 23 villages distributed throughout most of the peninsula. A high abundance of bugs was observed in the northern part of the peninsula, indicating a prioritary area for vector control. Part of this distribution could be attributed to the type of vegetation. We also documented strong seasonal variations in T. dimidiata populations, with a higher abundance during the hot and dry season in April-June. These variations, associated with reduced year-round colonization of houses and the analysis of developmental stage structure, suggest that flying adults seasonally invading houses may play a larger role than domiciliated bugs in transmission of Trypanosoma cruzi to humans. The importance of this transmission dynamics may not be limited to the Yucatan peninsula, but may be a general mechanism contributing to natural transmission that should be taken into account in other regions for the design and optimization of control strategies.

Re-infestation of houses by Triatoma dimidiata after intra-domicile insecticide application in the Yucatán peninsula, Mexico

“…We selected two villages: Eknackán and Dzidzilche, where we had been working since 1999 and had observed levels of house infestation by T. dimidiata of about 20 bugs/ house/year (Dumonteil et al 2002). During our previous studies in these villages, the majority of bugs were collected between April and June, and about 80% of the houses were infested.…”

“…In a previous study, we documented strong seasonal variation in domiciliated and peridomestic populations. The analysis of the population stage structure led us to suggest that flying adults (from sylvatic or peridomestic environments) were seasonally infesting houses (Dumonteil et al 2002). An important implication of this conclusion is that control programs may have to be designed to take this particular behaviour into account.…”

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

“…Las muestras se etiquetaron y conservaron a una temperatura de 2ºC a 6ºC durante su transporte al laboratorio. Las muestras se centrifugaron para separar el suero, mismo que fue conservado a -20ºC para su posterior análisis mediante la técnica de PCR (Edwards et al 1991, Dumonteil et al 2002.…”

The number of families of Triatoma dimidiata in a Guatemalan house

“…This suggests that there are other causes such as migration which is known to occur in some populations of T. dimidiata. In Costa Rica (Zeledon et al 2001), the Yucatan (Dumonteil et al 2002), and Northern Guatemala (Monroy et al 2003b) seasonal migration occurs during the dry season; however in Belize, the peak migration is during the rainy season (Petana 1971). We know that the nymphs and adults are mobile as some bugs collected outside houses contained human blood (Zeledon et al 2005), and some bugs collected inside houses contained wild animal blood (Sasaki et al 2003).…”