Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in two Kenyan referral hospitals
Lucinde R., Mugo D., Bottomley C., Aziza R., Gitonga J., Karanja H., Nyagwange J., Tuju J., Wanjiku P., Nzomo E., Kamuri E., Thuranira K., Agunda S., Nyutu G., Etyang A., Adetifa IMO., Kagucia E., Uyoga S., Otiende M., Otieno E., Ndwiga L., Agoti CN., Aman R., Mwangangi M., Amoth P., Kasera K., Nyaguara A., Ng’ang’a W., Ochola LB., Barasa E., Bejon P., Tsofa B., Ochola-Oyier LI., Warimwe GM., Agweyu A., Scott JAG., Gallagher KE.
The high proportion of SARS-CoV-2 infections that remain undetected presents a challenge to tracking the progress of the pandemic and implementing control measures in Kenya. We determined the prevalence of IgG to SARS-CoV-2 in residual blood samples from mothers attending antenatal care services at 2 referral hospitals in Kenya. We used a validated IgG ELISA for SARS-Cov-2 spike protein and adjusted the results for assay sensitivity and specificity. In Kenyatta National Hospital, Nairobi, seroprevalence in August 2020 was 49.9% (95% CI 42.7-58.0). In Kilifi County Hospital seroprevalence increased from 1.3% (95% CI 0.04-4.7) in September to 11.0% (95% CI 6.2-16.7) in November 2020. There has been substantial, unobserved transmission of SARS-CoV-2 in parts of Nairobi and Kilifi Counties.