Natural malaria infection in anophelines vectors and their incrimination in local malaria transmission in Darien, Panama

Authors: TORRES COSME, ROLANDO - Gorgas Memorial Institute Of Health Studies; RIGG, CHYSTRIE - Gorgas Memorial Institute Of Health Studies; SANTAMARIA, ANA - Gorgas Memorial Institute Of Health Studies; VASQUEZ, VANESSA - Gorgas Memorial Institute Of Health Studies; VICTORIA, CARLOS - Ministry Of Health - Panama; Ramirez, Jose; CALZADA, JOSE - Gorgas Memorial Institute Of Health Studies; CARRERA, LORENZO - Gorgas Memorial Institute Of Health Studies

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2021
Publication Date: 5/3/2021
Citation: Torres-Cosme, R., Rigg, C., Santamaria, A.M., Vasquez, V., Victoria, C., Ramirez, J.L., Calzada, J., Carrera, L.C. 2021. Natural malaria infection in anophelines vectors and their incrimination in local malaria transmission in Darien, Panama. PLoS ONE. 16(5). Article e0250059. https://doi.org/10.1371/journal.pone.0250059.
DOI: https://doi.org/10.1371/journal.pone.0250059

Interpretive Summary: Malaria, a disease caused by a parasite transmitted by female Anopheles mosquitoes continue to be a significant public health challenge in Latin America. The region of Darien, in Panama, is highly forested and home to about nine mosquito species that are potential malaria vectors. This study reported the first record of a natural malaria infection in An. darlingi mosquitoes. The results of this study will contribute to the improvement of mosquito control and disease surveillance efforts aimed at malaria elimination.

Technical Abstract: Background More than 85% of the malaria cases in Panama occur in poor, rural and indigenous regions like Darien Province. Vector diversity, infection rate and spatial distribution are important entomological parameters of malaria transmission dynamics. Their understanding is crucial for the development of effective disease control strategies. The objective of this study was to determine the composition of Anopheles species, their natural infection rate and their geographic distribution to better understand the malaria transmission dynamics in Darién, Panama. Methods Anophelines mosquitoes were captured during the rainy and dry season of 2016. We selected five communities where adult anophelines were collected using CDC light-traps, and through protective human-baited traps. Detection of natural infection and Plasmodium genotype were detected via nested PCR through the amplification of ssrRNA and the circumsporozoite protein gene (csp), respectively. Results A total of 1,063 mosquitoes were collected mosquitoes were collected for the detection of natural infection with Plasmodium spp. Nine Anophelines species were identified, with the predominant species being: An. (Nys.) darlingi (45.0%) and An. (Nys.) albimanus (42.6%). Natural infection in An. (Nys.) albimanus with P. vivax was detected in one mosquito pool from the community Pueblo Tortuga (0.6%), three from Marraganti (1.7%), two from Bajo Chiquito (1.1%) and three pools from Alto Playona 3 (1.7%). For An. (Nys.) darlingi mosquitoes, we detected seven positive pools from the community Bajo Chiquito (4.0%), two pools from Marraganti (1.1%) and two pools from Alto Playona (1.1%). The P. vivax allelic variant VK210 was detected in infected mosquitoes. Conclusion The results from this study provide new information on the transmission dynamics associated with anophelines vectors in the Darién region. This is the first report of natural P. vivax infection in An. (Nys.) darlingi and its incrimination as a potential malaria vector in this region of Panama. Additional studies are necessary to expand our knowledge and determine crucial parameters in malaria transmission in Darién, which in turn will aid the National Malaria Program in attaining an adequate malaria control strategy towards malaria elimination.