Pyrethroid-Resistance in Triatoma Infestans (Hemiptera: Reduviidae): A Systematic Review and Meta-Analysis Study

ROCA-ACEVEDO, G.; MATAMOROS, G.; TOLOZA, A. C.

Current Tropical Medicine Reports

Springer Nature Switzerland AG

Año: 2025 vol. 12

Purpose of Review The most widely used strategy to reduce the incidence of Triatoma infestans, the primary vector of Chagas disease in Latin America, is to spray dwellings with pyrethroids for chemical control of the vector. However, the long-term use of pyrethroid insecticides in T. infestans control campaigns has led to the development of resistance in treated populations. This meta-analysis study identified the emergence, patterns in the geographical distribution and the mechanism involved of the pyrethroid resistance in populations of T. infestans from Argentina, Bolivia, Brazil and Paraguay. Recent Findings A meta-analysis of 25 studies revealed significant heterogeneity, indicated by an I2 value of 99.80%. This indicated that the differences observed between the studies were correct and not a random bias. A T2 value of 0.43 indicates significant variability in effect size across studies. An overall random pooled effect size of 0.92 (95% CI 0.66–1.18) was observed across the studies, indicating that insecticide resistance values were generally higher in all evaluated manuscripts.Out of 196 studied populations, 165 (84.2%) analyzed the toxicological effects of the pyrethroid deltamethrin on T. infestans in Argentina, Bolivia, Brazil, and Paraguay. Among these populations, 14 (8.43%) were classified as susceptible, 48 (28.92%) as having low resistance (RR, 41 (24.7%) as having medium resistance, and 62 (37.35%) as exhibiting high resistance. Additionally, four deltamethrin resistance hotspots were identified: a) an extended region around the Argentinian-Bolivian border with RRs between 79 to 541; b) the area in the Güemes Department of Chaco Province in Argentina with RRs ranging from0 to > 2000; c) the Bolivian border area between the departments of Tarija and Chuquisaca showing RR values between 142; and d) The northern region of Potosí with RRs between 25.1 and 47. Summary Chagas disease is a significant health concern classified as a Neglected Tropical Disease (NTD) due to its considerableimpact on impoverished populations, primarily in rural and peri-urban areas of Latin America. The most widelyused strategy to reduce the incidence of this endemic disease is to spray dwellings with pyrethroids for chemical control of the vector. The differences in deltamethrin resistance levels detected in the studied populations could be attributed to several non-exclusive factors like insecticide pressure, environmental variables, population genetic structure, and insecticide resistance mechanisms.