Infestation byTriatoma pallidipennis(Hemiptera: Reduviidae: Triatominae) Is Associated with Housing Characteristics in Rural Mexico

Abstract

Long-term control of Chagas disease requires not only interruption of the human transmission cycle of Trypanosoma cruzi Schyzotrypanum, Chagas, 1909 by controlling its domestic triatomine vectors but also surveillance to prevent reinfestation of residences from sylvatic or persistent peridomestic populations. Although a number of potential risk factors for infestation have been implicated in previous studies, the explanatory power of resulting models has been low. Two years after cessation of triatomine vector control efforts in the town of Chalcatzingo, Morelos, 78 environmental, socioecological, and spatial variables were analyzed for association with infestation by Triatoma pallidipennis Stal 1872 (Hemiptera: Reduviidae: Triatominae), the principal vector of T. cruzi. We studied 712 residences in this rural community to identify specific intradomestic and peridomestic risk factors that predicted infestation with T. pallidipennis. From numerous characteristics that were identified as correlated with infestation, we derived multivariate logistic regression models to predict residences that were more or less likely to be infested with T. pallidipennis. The most important risk factors for infestation included measurements of house age, upkeep, and spatial location in the town. The effects of certain risk factors on infestation were found to be modified by spatial characteristics of residences. The results of this study provide new information regarding risk factors for infestation by T. pallidipennis that may aid in designing sustainable disease control programs in rural Mexico.

Eco-Bio-Social Determinants for House Infestation by Non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico

“…Risk factors for house infestation (and colonization) by T. infestans are typically associated with housing structure and quality; houses providing abundant hiding refuges for bug resting and reproduction (cracked adobe walls, dirt floors, thatched roofs, poor hygiene, darkness, etc..) and easily accessible feeding sources (indoor dogs or chickens, large families) are more likely to be infested [9]–[11]. Similar results have been observed for other domiciliated vector species and populations, including T. dimidiata in Central America [12]–[16]. Accordingly, integrated vector control interventions targeting these risk factors such cement floors or roofs, or wall plastering are being evaluated [17]–[19] as alternatives to conventional insecticide spraying [20], [21].…”

“…However, when houses were grouped according to their predicted infestation, the model then accounted for up to 85% of the variations in the observed infestation index. Unfortunately, the predictive value of models is rarely reported by authors attempting to identify risk factors, even though they often base subsequent vector control interventions on such studies, with little certainty that infestation will actually be affected [9], [12]–[15], [17]–[19]. The general practice is to use odds ratio statistics to identify key risk factors, but the actual capacity of the key factors to predict the level of risk is not assessed.…”

Community Participation in Chagas Disease Vector Surveillance: Systematic Review

“…Table 1 summarises the results of major reports on Chagas disease vector control [5],[18],[44],[57],[61],[63],[71]–[73],[77]–[113]. Overall, these studies unequivocally show that household insecticide spraying has successfully reduced infestation rates throughout Latin America, but also that reinfestation of dwellings by native vector species is common, spatially widespread, and temporally persistent.…”

Trypanosoma cruzi reservoir—triatomine vector co-occurrence networks reveal meta-community effects by synanthropic mammals on geographic dispersal

“…A gradient of synanthropy occurs in T. cruzi vector species in North America (Ibarra-Cerdeña et al, 2009), with highly synanthropic species, such as T. pallidipennis and most phyllosoma complex species (Enger et al, 2004; Cohen et al, 2006; Ramsey et al, 2012) and T. dimidiata haplogroups (Dumonteil & Gourbiére, 2004; Guzmán-Tapia, Ramirez-Sierra & Dumonteil, 2007; Lopez-Cancino et al, 2015), or partially synanthropic, such as T. barberi (Ramsey et al, 2000; Martínez-Ibarra et al, 2008). Reservoirs such as Rattus rattus or Mus musculus represent the case for highly synanthropic rodent species (Khlyap & Warshavsky, 2010), and Sigmodon hispidus or Liomys irroratus as partially synanthropic, all of them important reservoirs of T. cruzi (Ramsey et al, 2012; Lopez-Cancino et al, 2015).…”