Anopheline diversity in urban and peri-urban malaria foci: comparison between alternative traps and seasonal effects in a city in the Western Brazilian Amazon

• Published in: Malaria Journal
• Main Authors: Anne Caroline Alves Meireles, Lucas Rosendo da Silva, Marlon Ferreira Simplício, Alzemar Alves de Lima, Flávia Geovana Fontineles Rios, Carla Augusta de Menezes, Luiz Henrique Maciel Feitoza, Genimar Rebouças Julião
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2022
• Subjects: Human Landing Catch; Seasonality; Barrier screen; Biting behaviour; An. darlingi; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-022-04274-8; https://doaj.org/article/2b62341977d94efeb122853bf59e720e

Abstract Background Continuous vector surveillance and sustainable interventions are mandatory in order to prevent anopheline proliferation (or spread to new areas) and interrupt malaria transmission. Anopheline abundance and richness were evaluated in urban and peri-urban malaria foci at a medium-sized city in the Brazilian Amazon, comparing the protected human landing catch technique (PHLC) and alternative sampling methods over different seasonal periods. Additional information was assessed for female feeding behaviour and faunal composition. Methods Anophelines were sampled bimonthly in four urban and peri-urban sites in the city of Porto Velho, state of Rondônia, Brazil. The average number of captured mosquitoes was compared between an PHLC (gold standard), a tent trap (Gazetrap), and a barrier screen by means of generalized linear mixed models (GLMM), which also included season and environment (peri-urban/urban) as predictors. Results Overall, 2962 Anopheles individuals belonging to 12 species and one complex were caught; Anopheles darlingi represented 86% of the individuals. More mosquitoes were captured in the peri-urban setting, and the urban setting was more diverse. The model estimates that significantly more anophelines were collected by PHLC than by the Screen method, and Gazetrap captured fewer individuals. However, the Screen technique yielded more blood-engorged females. The peak hours of biting activity were from 6 to 7 p.m. in urban areas and from 7 to 8 p.m. in peri-urban areas. Conclusions Although peri-urban settings presented a greater abundance of anophelines, Shannon and Simpson diversities were higher in urban sites. Each technique proved to be useful, depending on the purpose: PHLC was more effective in capturing the highest anopheline densities, Gazetrap caught the greatest number of species, and the barrier screen technique captured more engorged individuals. There was no seasonal effect on Anopheles assemblage structure; however, a more diverse fauna was caught in the transitional ...