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

Abstract

BackgroundMalaria is endemic in Darién and an assessment of the different factors affecting its epidemiology is crucial for the development of adequate strategies of surveillance, prevention, and disease control. The objective of this study was to determine the main characteristics of the epidemiological behavior of malaria in the Darien region.MethodsThis research was comprised of a retrospective analysis to determine the incidence and malaria distribution in the Darien region from 2015 to 2017. We evaluated malaria indicators, disease distribution, incidence (by age group and sex), diagnostic methods, treatment, and control measures. In addition, we examined the cross-border migration activity and its possible contribution to the maintenance and distribution of malaria.ResultsDuring 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 comprised 62.7% of the total diagnosed cases. Meanwhile, a similar percentage, 62.7%, of the total cases were registered in economically active ages. 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 1.2% and the annual blood examination rate (ABER) 22.5%. In Darién there is a constant internal and cross-border migration movement between Panama and Colombia. Malaria control measures consisted of the active and passive search of suspected cases and of the application of vector control measures.ConclusionThis study provides an additional perspective on malaria epidemiology in Darién. Additional efforts are required to intensify malaria surveillance and to achieve an effective control, eventually moving closer to the objective of malaria elimination. At the same time, there is a need for more eco-epidemiological, entomological and migratory studies to determine how these factors contribute to the patterns of maintenance and dissemination of malaria.

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

“…The communities that yielded P. vivax positive mosquito pools also registered active malaria transmission during our study, with the highest number of cases observed during the transition period between the rainy season and the dry season [5]. The dynamics of malaria epidemics are strongly influenced by climate.…”

“…The term comarca refers to an administrative region within Panama and it is assigned to a given indigenous population. The eastern side of Panama, where Darién is located, has seen 61.5% of national malaria cases in the last years [5]. The climate of this region is tropical, with high humidity like the rest of Panama, and it is influenced by the intertropical convergence zone [25].…”

“…This is in part due to the geographical isolation and the lack of access to public health services, poverty and illiteracy. Indigenous regions, which occupy 22% of the national territory and only 12% of the total population, register more than 85% of the total malaria diagnosed cases [5]. The variations that occur in these regions determine the main changes affecting malaria epidemiology in Panama.…”

Long-Term Transmission Patterns and Public Health Policies Leading to Malaria Elimination in Panamá

“…Indeed, many migrants are from countries where drug resistant strains circulate, a fact that continuously challenges the national malaria program treatment policies [19]. In fact, recent P. falciparum outbreaks in areas where malaria transmission had been previously interrupted have been linked to migratory events across the Panamanian-Colombian border [9,[55][56][57]76]. During this period (2000-2019) a significant and increasing proportion of the P. falciparum total cases were imported, mainly from Colombia (Additional files 3 and 4).…”

Long-Term Transmission Patterns And Public Health Policies Leading To Malaria Elimination In Panamá

“…Indeed, many migrants are from countries where drug resistant strains circulate, a fact that continuously challenges the national malaria program treatment policies [19]. In fact, recent P. falciparum outbreaks in areas where malaria transmission had been previously interrupted have been linked to migratory events across the Panamanian-Colombian border [9,[55][56][57]76]. During this period (2000-2019) a signi cant and increasing proportion of the P. falciparum total cases were imported, mainly from Colombia (Additional les 3 and 4).…”