Seroprevalence of Anti-Sars-Cov-2 Antibodies among Patients Visiting Hospital-Based Sentinel Sites in the Rift Valley Region, Kenya DOI: https://dx.doi.org/10.4314/ajhs.v38i1.2

Abstract

Background: Accurate estimation of the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for guiding public health prevention strategies. Underreporting from polymerase chain reaction (PCR) based testing, especially in low- and middle-income countries, often obscures the true extent of exposure and immunity to coronavirus disease 2019 (COVID-19). This study aimed to determine the seroprevalence and antibody levels against SARS-CoV-2 among patients visiting hospital-based sentinel sites in Kenya’s Rift Valley region.

Method: A cross-sectional study was conducted at four hospital-based sentinel sites among patients with symptoms of acute respiratory infection. Patients aged six months or older visiting the sites between January 2022 and December 2022, presenting with symptoms of acute respiratory infection, were enrolled. Clinical and sociodemographic data were collected using a structured questionnaire. A quantitative enzyme-linked immunosorbent assay (ELISA) kit detected IgG antibodies against SARS-CoV-2 S protein in serum samples.

Results: Among 557 individuals enrolled in the study, the seroprevalence of SARS-CoV-2 antibodies was 97.8% (n=545). Vaccinated individuals demonstrated significantly higher odds of seropositivity compared to unvaccinated counterparts, with an odds ratio of 3.33 (95% CI: (0.4, 27.87). While seropositivity remained consistent across age groups, older adults exhibited the highest odds. Site-specific differences in enrolment and vaccination rates highlight potential access-related disparities.

Conclusion: Our findings indicate prior exposure to SARS-CoV-2 within the study region, underscoring the significant impact of natural infection and vaccination efforts in driving SARS-CoV-2 seroprevalence within the Rift Valley region. Despite the underestimation of infections and disparities in vaccination access, this study demonstrates the effectiveness of vaccination for conferring SARS-CoV-2 immunity. To ensure equitable vaccination coverage, targeted interventions should focus on increasing vaccine accessibility through mobile clinics and community-based vaccination campaigns while addressing vaccine hesitancy through targeted public health messaging and community engagement.