Seroprevalence of anti-SARS-CoV-2 and anti-Plasmodium falciparum and vivax antibodies in urban and rural zones in the West Region of Cameroon.

BACKGROUND: In Sub-Saharan Africa the precarious health situation resulting from malaria has been further complicated by the emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). However, data on the burden of the virus in Cameroon remains limited. Here, we estimated prevalence of anti-SARS-CoV-2 and anti-Plasmodium antibodies in urban and rural areas of the West Region of Cameroon during April and May 2022.

METHODS: This was a cross-sectional study performed in Bafoussam (urban) and Fongo-Tongo (rural) in the West Region of Cameroon. Rapid diagnostic tests were used to detect anti-SARS-CoV-2 and anti-Plasmodium antibodies from whole blood samples collected via finger puncture. A total of 805 participants were included in the study. The association between seropositivity and recent history of common COVID-19 symptoms as well as the presence of anti-SARS-CoV-2 and anti-Plasmodium antibodies were analysed using the logistic regression model.

RESULTS: The overall antibody seroprevalence was 60.1% for SARS-CoV-2. In urban settings, the seroprevalence was 66.6%, including 62.11% IgG positivity, 0.9% IgM, and 2.7% co-detection of both IgG and IgM antibodies. In rural zone it was 54.0% with 51.8% of positivity due to IgG, 0.3% of IgM and 1.9% co-detection of both IgG and IgM antibodies. The overall seroprevalence of anti-Plasmodium antibodies was 22.2% and was high in rural zone with 31.4% compared to 14.8% reported in urban zone. Of the total seroprevalence, anti-Plasmodium antibodies of 21% was attributed to P. falciparum, while 2.11% was due to P. vivax. The generalised linear binomial model revealed no association between the presence of anti-SARS-CoV-2 antibodies and anti-Plasmodium antibodies. SARS-CoV-2 antibody presence was associated with symptoms such as fever, dry cough, headache, loss of taste and smell, and body aches while fever, Sore-throat diarrhoea were found as symptoms associated to anti-Plasmodium antibodies. Additionally, a positive association between SARS-CoV-2 IgM antibodies and Plasmodium antibodies was observed.

CONCLUSION: This study demonstrated a moderate-to-high seroprevalence of both anti-SARS-CoV-2 and anti-Plasmodium antibodies in urban and rural areas of Cameroon. However, further research is required to determine the persistence delay as well as the functionality of these assayed antibodies.