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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Crop Bioprotection Research » Research » Publications at this Location » Publication #359650

Research Project: New Microbial and Plant-Based Agents for Mosquito Control

Location: Crop Bioprotection Research

Title: Study of the epidemiological behavior of malaria in Darien Region, Panama. 2015–2017

item CACERES CARRERA, LORENZO - Gorgas Memorial Institute Of Health Studies
item VICTORIA, CARLOS - Ministry Of Health - Panama
item Ramirez, Jose
item JACKMAN, CARMELA - Ministry Of Health - Panama
item CALZADA, JOSE - Gorgas Memorial Institute Of Health Studies
item TORRES-COSME, ROLANDO - Gorgas Memorial Institute Of Health Studies

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2019
Publication Date: 11/15/2019
Citation: Caceres Carrera, L., Victoria, C., Ramirez, J.L., Jackman, C., Calzada, J.E., Torres, R. 2019. Study of the epidemiological behavior of malaria in Darien Region, Panama. 2015–2017. PLoS ONE. 14(11):e0224508.

Interpretive Summary: Malaria is a disease of great public health concern in Panama. In particular, the Darien region presents the highest number of malaria cases in Panama. This study evaluated the factors associated with malaria transmission in the Darien region. The study found that most malaria cases are due to infections with the malaria parasite Plasmodium vivax. Nine species of mosquitoes were collected and identified in this study as potential malaria vectors. Two mosquito species, Anopheles albimanus and An. darlingi, were found to be naturally infected with the malaria parasite. This is the first report of a natural malaria parasite infection in a field-collected An. darlingi mosquito. Malaria represents a major public health problem around the world and the results from this study will contribute to the improvement of disease surveillance efforts and to the elimination of malaria.

Technical Abstract: The evaluation of the different factors determining malaria epidemiology is crucial for the development of adequate strategies of surveillance, prevention and disease control. Objective: The objective of this study was to determine the eco-epidemiological factors associated with the frequency and distribution of malaria transmission in the Darién region. Methods: This research was comprised of observational, descriptive, retrospective and cross-sectional studies designed to measure the main factors associated with the prevalence, incidence and distribution of malaria in the Darién region from 2015 to 2017. We evaluated malaria indicators, disease distribution and incidence, diagnostic and treatments, identification of anopheline species, genotyping of the circulating Plasmodium strain and its detection in Anopheles mosquitoes. Results: During the period of 2015-2017 we examined 41,141 thick blood smear samples, out of which 501 tested positive for malaria. Plasmodium vivax was responsible for 92.2 % of those infections. Males constituted 62.7% of the total cases, with 62.7% belonging to the economically active population. The more frequent symptoms included fever (99.4 %) and chills (97.4 %), with 53.1 % of cases registering between 2,000 and 6,000 parasites/µl of blood. The annual parasitic incidence (API) average was 3.0/1,000 inhabitants, while the slide positivity rate (SPR) was 1.4% and the annual blood examination rate (ABER) 22.5 %. We identified nine anopheline species: An. albimanus, An. darlingi, An. pseudopunctipennis, An. punctimacula, An. oswaldoi s.l, An. malefactor, An. triannulatus s.l, An. apicimacula and An. strode. Natural P. vivax infections was only detected in An. albimanus and An. darlingi mosquitoes. Genotyping of P. vivax indicated the presence of allelic variant VK210. Conclusion: Given its geographical location, bordering region with Colombia, the Darién region presents an epidemiological pattern that is tightly associated with migrant movements, socio-economic, socio-environmental, cultural and ecological factors, making this region very vulnerable and receptive to the establishment of malaria transmission. These factors constitute the epidemiological framework of malaria, and their evaluation, as a group, is crucial to the development of adequate strategies of surveillance, prevention and disease control in this region.