New Findings of Insecticide Resistance in Triatoma infestans (Heteroptera: Reduviidae) From the Gran Chaco

Abstract

Chagas disease is a major health concern in Latin America, and Triatoma infestans (Klug, 1834) is responsible for the majority of cases of Chagas disease in the continent. After the discovery of deltamethrin highly resistant populations in the neighboring areas to Yacuiba (Bolivia) and Salvador Mazza (Argentina), we studied T. infestans populations north and southward, with the aim of describing the range of the resistant area. In addition, tests were conducted to describe the susceptibility to fipronil in deltamethrin-resistant populations. Tarija populations were highly resistant to deltamethrin, showing that the resistant area is greater than previously reported. Argentinean and Paraguayan populations were susceptible or presented moderate to low levels of deltamethrin resistance. Resistance to fipronil was found in Bolivian populations, although this insecticide was effective against Argentinean populations. This study shows that the Argentinean and Paraguayan populations are currently under successful control with deltamethrin. However, continuous resistance monitoring is necessary. We found that fipronil is a viable option for Argentina, whereas the resistance found in Bolivia implies that new formulations are needed to control T. infestans in Bolivia. Further research is required to find new alternatives of control in those areas that are currently suffering from high infestation rates.

Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae) in Bolivia: new discoveries

“…Previous data showed that resistance of domestic T. infestans to deltamethrin is widespread, high in Argentina (Vassena & Picollo 2003, Audino et al 2004) and particularly high in Bolivia, where the highest levels of resistance were observed in the department of Tarija (Alarico et al 2010, Germano et al 2010, Lardeux et al 2010). The present results confirmed this tendency, with the highest RR observed in the domestic population of Taiguati (RR = 818), a colony of approximately 25 specimens collected in a henhouse.…”

Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal

“…2014), the emergence of insecticide resistance (Germano et al . 2010; Lardeux et al . 2010) and decentralized vector control initiatives in areas of recurrent political, social and economic instability (Gürtler 2009).…”

Susceptibility to deltamethrin of wild and domestic populations of Triatoma infestans of the Gran Chaco and the Inter-Andean Valleys of Bolivia

“…It is considered that vector control failures, are due to high levels of insecticide resistance in this area [18][19][20][21]. In the last few years, more studies demonstrated that the phenomenon of resistance to insecticides in domestic T. infestans populations presents an extensive distribution in southern Bolivia and northern Argentina [21][22][23], with high resistance ratios, and different toxicological profiles [14,18,19,[24][25][26].…”