Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa Rica

Abstract

Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/μl. The majority of the cases were observed in May and June. Two mosquito vector species were identified-- Anopheles albimanus and An. punctimacula. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation of work performance in the border region. This will require coordination with health authorities of both countries to control malaria in this region.