The clinical–epidemiological profile of malaria patients from Southern Venezuela, a critical hotspot in Latin America

Abstract

Background Venezuela accounted for 55% of the cases and 73% of the malaria deaths in the Americas in 2019. Bolivar state, in the southeast, contributes > 60% of the country's Plasmodium vivax and Plasmodium falciparum cases every year. This study describes the clinical–epidemiological characteristics of clinical malaria patients in this high-transmission area. Methods A prospective study was conducted on patients seeking medical attention in three medical centres in the state capital, Ciudad Bolivar, between June and October 2018. Malaria diagnosis was carried out using microscopy following national standards. Malaria-positive patients were examined for clinical symptoms, and haematological tests were performed at the time of diagnosis. Patients were followed up by telephone to evaluate malaria recurrences. Results Out of 287 patients, 200 (69.7%) were positive for P. vivax, 69 (24%) for P. falciparum, and 18 (6.3%) had mixed (P. vivax/P. falciparum) infections. Patients' median age was 33 years (IQR 20), 168 (69%) were men, and 40% practiced gold mining as the main occupation. Fever (96.5%), chills (91.3%), and headaches (90.6%) were the most frequent symptoms. At least one symptom associated with severe malaria was observed in 69 out of 161 patients with complete clinical evaluation (42.9%). Plasmodium vivax infections were found in 42 out of 69 (60.9%) severe cases; by contrast, P. falciparum and mixed malaria caused 34.8% (24/69) and 4.4% (3/69) of infections, respectively. Two patients died of cerebral malaria. Mean hemoglobin was lower in the patients infected with P. falciparum than those infected with P. vivax. Regardless of the parasite causing the infection, patients presented high levels of total bilirubin, aminotransferases (AST, ALT), and lactate dehydrogenase (LDH). Out of the 142 patients followed up by phone for three months (49.5% of the 287 patients), 35 (24.7%) reported recurrences. Conclusions The high malaria prevalence among young male adults practicing gold mining suggests that this occupation is a significant risk factor. The unexpected high prevalence of P. vivax patients with at least one criteria of severe clinical disease is a matter of concern. Whether it is the result of a lack of timely diagnosis and effective treatment should be explored.

Malaria Resilience in South America: Epidemiology, Vector Biology, and Immunology Insights from the Amazonian International Center of Excellence in Malaria Research Network in Peru and Brazil

“…As studied by ICEMR investigators and other, illegal gold mining has been regularly associated with malaria outbreaks in Peru, 13 , 14 Brazil, 16 and elsewhere in South America, 46 , 59 , 60 , 73 , 74 associated with gold miner occupation-related mobility as one epidemiological feature both in terms of malaria-naïve individuals arriving to an area of malaria transmission as well as infected gold miners bringing malaria away from such sites of transmission. 16 , 46 , 59 , 60 , 73 , 74 …”

“… 32 , 57 , 58 Recently, we started pilot studies in Venezuela as it is a source of cross-border malaria in Northern Brazil. 16 , 59 , 60 …”

Manejo clínico-terapéutico de la malaria grave

“…En el año 2021, Forero-Peña D et al publicaron los resultados de un estudio en el Estado Bolívar, con elevada prevalencia de infección por Plasmodium vivax, con al menos un criterio de enfermedad clínica severa 21 .…”