@article{Lucinde_R-2022_173306,
title = {Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in three Kenyan referral hospitals: Repeated cross-sectional surveys 2020-21},
author = {Lucinde, R. and Mugo, D. and Bottomley, C. and Karani, A. and Gardiner, E. and Aziza, R. and Gitonga, J. and Nyagwange, J. and Karanja, H. and Nyagwange, J. and Tuju, J. and Wanjiku, P. and Nzomo, E. and Kamuri, E. and Thuranira, K. and Agunda, S. and Nyutu, G. and Etyang, A. and Adetifa, I. and Kagucia, E. and Uyoga, S. and Otiende, M. and Otieno, E. and Ndwiga, L. and Agoti, C. and Aman, R. and Mwangangi, M. and Amoth, P. and Kasera, K. and Nyaguara, A. and Ng’ang’a, W. and Ochola, L. and Namdala, E. and Gaunya, O. and Okuku, R. and Barasa, E. and Bejon, P. and Tsofa, B. and Ochola-Oyier, L. and Warimwe, G. and Agweyu, A. and Scott, J. and Gallagher, K.},
month = {oct},
year = {2022},
abstract = {The high proportion of SARS-CoV-2 infections that have remained undetected presents a challenge to tracking the progress of the pandemic and estimating the extent of population immunity.&lt;h4&gt;Methods&lt;/h4&gt;We used residual blood samples from women attending antenatal care services at three hospitals in Kenya between August 2020 and October 2021and a validated IgG ELISA for SARS-Cov-2 spike protein and adjusted the results for assay sensitivity and specificity. We fitted a two-component mixture model as an alternative to the threshold analysis to estimate of the proportion of individuals with past SARS-CoV-2 infection.&lt;h4&gt;Results&lt;/h4&gt;We estimated seroprevalence in 2,981 women; 706 in Nairobi, 567 in Busia and 1,708 in Kilifi. By October 2021, 13% of participants were vaccinated (at least one dose) in Nairobi, 2% in Busia. Adjusted seroprevalence rose in all sites; from 50% (95%CI 42-58) in August 2020, to 85% (95%CI 78-92) in October 2021 in Nairobi; from 31% (95%CI 25-37) in May 2021 to 71% (95%CI 64-77) in October 2021 in Busia; and from 1% (95% CI 0-3) in September 2020 to 63% (95% CI 56-69) in October 2021 in Kilifi. Mixture modelling, suggests adjusted cross-sectional prevalence estimates are underestimates; seroprevalence in October 2021 could be 74% in Busia and 72% in Kilifi.&lt;h4&gt;Conclusions&lt;/h4&gt;There has been substantial, unobserved transmission of SARS-CoV-2 in Nairobi, Busia and Kilifi Counties. Due to the length of time since the beginning of the pandemic, repeated cross-sectional surveys are now difficult to interpret without the use of models to account for antibody waning.},
volume = {17},
issue = {10},
journal = {PLoS ONE},
publisher = {Public Library of Science},
url = {https://doi.org/10.1371/journal.pone.0265478},
}
