Viral and bacterial pathogens among malaria patients in an endemic area of southern Venezuela

Abstract Background Malaria remains a leading public health problem worldwide. Co-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and management. Similarities in the clinical presentation of malaria and other infections and overlapping endemicity result in the underdiagnoses of co-infections and increased mortality. To date, no study has focused on co-infections or co-circulation of other pathogens in malaria-endemic areas in Venezuela. Methods A cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar, Venezuela between June and November 2018. Clinical evaluation and laboratory tests for dengue virus (DENV), chikungunya virus (CHIKV), viral hepatitis (HAV, HBV, and HCV), and leptospirosis (LEP) were performed by enzyme-linked immunosorbent assay. Previous exposure to these pathogens was defined by the presence of specific IgG, and co-infection or recent exposure (CoRE) was determined by the presence of specific IgM alone or IgM plus IgG. Results A total of 161 malaria patients were studied, 66% infected with Plasmodium vivax, 27% with P. falciparum, and 7.5% harboured P. vivax/P. falciparum mixed infection. Previous exposure to DENV (60%) and CHIKV (25%) was frequent. CoRE was confirmed in 55 of the 161 malaria patients (34%) and were more frequent in P. falciparum (49%) than in P. vivax (29%) and mixed malaria patients (25%) (OR = 2.43; 95% CI = 1.39–4.25; p = 0.018). The most frequent CoRE was DENV (15%), followed by HAV (12%), HBV (6.2%), CHIKV (5.5%), and LEP (3.7%); HCV CoRE was absent. Complicated malaria was significantly more frequent in patients with CoRE (56%) than those without CoRE (36%; OR = 2.31; 95% CI = 1.18–4.92; p = 0.013). Conclusion We found a high prevalence of CoRE in malaria patients as determined by serology in the study region; cases were associated with a worse clinical outcome. Further prospective studies with samples from different sites of infection and the use of molecular tools are needed to determine the clinical significance of these findings.