Characterization of a recent malaria outbreak in the autonomous indigenous region of Guna Yala, Panama

Abstract

BackgroundThis study aims to describe the epidemiological and entomological factors associated with a recent malaria outbreak that occurred in 2012 in a socially marginalized population from Guna Yala Comarca in Panama.MethodsA descriptive and observational study was conducted by analysing demographic and epidemiological data from all malaria cases registered during 2012 in the Comarca Guna Yala, Panama. Malaria intensity indicators were calculated during the study period. Entomological evaluations were performed monthly, from October to December 2012, in the three communities that presented the most intense malaria transmission during the first semester of 2012. Anopheles breeding habitats were also characterized.ResultsDuring the studied period, 6754 blood smears were examined (17.8 % of the total population), and 143 were confirmed as positive for Plasmodium vivax. A significant increase of malaria transmission risk indicators (API: 3.8/1000, SPR: 2.1 %) was observed in Guna Yula, when compared with previous years, and also in comparison with estimates from the whole country. Anopheles albimanus was the most abundant and widespread (877; 72.0 %) vector species found in the three localities, followed by Anopheles punctimacula (231; 19.0 %) and Anopheles aquasalis (110; 9.0 %). Three An. albimanus pools were positive for P. vivax, showing an overall pooled prevalence estimate of 0.014.ConclusionsData analysis confirmed that during 2012 a malaria epidemic occurred in Guna Yala. Panama. This study provides baseline data on the local epidemiology of malaria in this vulnerable region of Panamá. This information will be useful for targeting control strategies by the National Malaria Control Programme.

Natural Malaria Infection in Anopheline Vectors and Their Incrimination in Local Malaria Transmission in Darién, Panama

“…(Nys. )albimanus) had the greatest density and biting activity between 18:30 and 19:30 hours, diminishing towards midnight as described in previous studies [26,32,44]. A study in Colombia also observed that the greatest intradomicile and peridomicile biting activity of An.…”

“…To determine the human biting rate per night (HBR), the PHBC consisted in simultaneously having one person intradomicile and another in the peridomicile per night in the four households within each locality. Mosquito collections were conducted during the 18:00 and 22:00 hours, given that previous reports have indicated that this is the period of greater mosquito biting activity [32,33]. Collections were made during the rst 50 min of every hour.…”

“…(Nys.) albimanus is considered of great entomological and epidemiological importance, being the predominant primary vector in lowland areas along the Paci c and Caribbean coast (32).…”

Long-term transmission patterns and public health policies leading to malaria elimination in Panamá

“…This is clearly illustrated by guna communities, where a disproportionate number of malaria cases (> 90% in 2019) occurs despite representing a relatively small proportion (around 2.4%) of the whole population [13,18]. This crucial obstacle has been previously identi ed in several studies and reports from indigenous communities in Panamá [9,10,71,72], but remains a neglected issue to be solved. In this line, it is important to improve health services and reduced socioeconomical disparities in the indigenous reservations, precisely where malaria transmission persists [11,14].…”

“…More than one century has passed since the opening of the Panamá Canal and despite the increasing economic development observed in the country during the past decade [8], malaria continues to be a major public health concern particularly affecting socially marginalized populations. Nearly 90% of the malaria cases registered in the country during the past 40 years are from poor indigenous regions, and around 1000 annual cases have been reported for the last 15 years, mostly (~ 94%) by Plasmodium vivax [9][10][11][12]; re ecting the neglected status of this disease and marked health inequities associated with ethnicity in Panamá [10,11]. Indeed, the degree of socioeconomic inequity in Panamá reaches a value of 49.9 according to the Gini coe cient; one of the highest in Latin America [13].…”