Seasonal malaria vector and transmission dynamics in western Burkina Faso

• Published in: Malaria Journal
• Main Authors: Patric Stephane Epopa, Catherine Matilda Collins, Ace North, Abdoul Azize Millogo, Mark Quentin Benedict, Frederic Tripet, Abdoulaye Diabate
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2019
• Subjects: Vector control; Genetic control; Seasonal dynamic; Anopheles gambiae s.l; Entomological Inoculation Rate; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Pala
• Online Access: https://doi.org/10.1186/s12936-019-2747-5; https://doaj.org/article/3bc6c2d56e4241909698e0e00b1baec1

Abstract Background In the context of widespread mosquito resistance to currently available pesticides, novel, precise genetic vector control methods aimed at population suppression or trait replacement are a potentially powerful approach that could complement existing malaria elimination interventions. Such methods require knowledge of vector population composition, dynamics, behaviour and role in transmission. Here were characterized these parameters in three representative villages, Bana, Pala and Souroukoudingan, of the Sudano-Sahelian belt of Burkina Faso, a region where bed net campaigns have recently intensified. Methods From July 2012 to November 2015, adult mosquitoes were collected monthly using pyrethroid spray catches (PSC) and human landing catches (HLC) in each village. Larval habitat prospections assessed breeding sites abundance at each site. Mosquitoes collected by PSC were identified morphologically, and then by molecular technique to species where required, to reveal the seasonal dynamics of local vectors. Monthly entomological inoculation rates (EIR) that reflect malaria transmission dynamics were estimated by combining the HLC data with mosquito sporozoite infection rates (SIR) identified through ELISA-CSP. Finally, population and EIR fluctuations were fit to locally-collected rainfall data to highlight the strong seasonal determinants of mosquito abundance and malaria transmission in this region. Results The principal malaria vectors found were in the Anopheles gambiae complex. Mosquito abundance peaked during the rainy season, but there was variation in vector species composition between villages. Mean survey HLC and SIR were similar across villages and ranged from 18 to 48 mosquitoes/person/night and from 3.1 to 6.6% prevalence. The resulting monthly EIRs were extremely high during the rainy season (0.91–2.35 infectious bites/person/day) but decreased substantially in the dry season (0.03–0.22). Vector and malaria transmission dynamics generally tracked seasonal rainfall variations, and ...