Post-vaccine Circulation of Group A Rotavirus among Children under Five in Northern Cameroon: A Cross-sectional Study

Abstract

Background: Rotavirus is the main viral agent involved in childhood gastroenteritis. It is a public health problem, characterized primarily by diarrhea, vomiting, and fever, spread via the fecal-oral route from contaminated water, food, and objects. The present study aims to determine the prevalence and seasonality of group A rotavirus (RVA) infection in children under 5 years of age admitted to hospitals in the city of Garoua for diarrhea. Methodology: This was a descriptive cross-sectional study conducted in Garoua between March 2023 and February 2024. It included 110 boys and 90 girls aged 0 to 5 years, admitted for acute diarrhea to the pediatric emergency departments of health facilities in the city of Garoua. Stool samples were collected for the detection of rotavirus A (RVA) VP6 protein using the sandwich ELISA Results: The ELISA test detected the RVA antigen in 17% (34/200) of the samples, including 26 boys and 8 girls. Children under 24 months of age were the most affected age group (44.1%), and (67.1%) were malnourished. Among the 34 infected children, RVA was responsible for 73.5% of hospitalizations. 88.2% (30/34) of positive cases were vaccinated (Rotarix) children, and 11.8% (4/34) were unvaccinated. Severe acute malnutrition was found to be a significant risk factor, affecting 41.1% of infected children. Although our results showed year-round occurrence of RVA infection, the dry season appears to be more conducive to infection than the rainy season. Conclusion: This study describes the evidence of RVA infection in diarrheal children under five years of age in the city of Garoua, despite the introduction of the Rotarix® vaccine into the Expanded Program on Immunization (EPI). The use of the ELISA method alone, without complementary genotyping, effectively limits the accurate evaluation of vaccine efficacy. While ELISA effectively detects antibodies, it cannot distinguish the vaccine-induced immune response from infections caused by variants, making it difficult to assess specific protection against circulating strains. This indicates a serious health burden, exacerbated by severe acute malnutrition at a younger age.