Seroprevalence and Combined Profiles of IgM/IgG Antibodies against SARS-CoV-2 in Ambulatory Patients in Yaoundé, Cameroon

Abstract

Aims: The study aims to assess the seroprevalence of anti-SARS-CoV-2 IgM and IgG antibodies among ambulatory patients in Yaoundé and to identify clinical and demographic correlates associated with the humoral immune response. Methods: An analytical cross-sectional study was conducted from February to July 2024 at the Central Hospital of Yaoundé. A probability sample of 350 adult patients was recruited. IgM and IgG antibodies were detected using indirect ELISA. Statistical analysis included the chi-square test, with a significance threshold of p < 0.05, multivariate logistic regression and multiple correspondence analysis (MCA). Results: The study population was predominantly female (55.7%). The adjusted overall seroprevalence was 26.67% for IgM and 53.73% for IgG. Analysis of combined immune responses revealed that 39.49% of patients were IgM+/IgG−, 50.21% were IgM−/IgG+ and 60.50% were IgM+/IgG+. Asthenia (39.7%) and myalgia (35.1%) were the most frequent clinical manifestations. Multivariate logistic regression identified IgM status as the only statistically significant determinant of IgG presence (p = 0.012). MCA confirmed the limited discriminative power of symptoms with respect to serological status. Conclusion: The study indicates a high level of exposure to SARS-CoV-2. The predominance of the IgM+/IgG+ profile suggests either an active infection phase or an important immunological transition within the hospital population, underscoring the need for continuous surveillance.