Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in three Kenyan referral hospitals: Repeated cross-sectional surveys 2020-21

Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in three Kenyan referral hospitals: Repeated cross-sectional surveys 2020-21

<p><strong>Introduction: </strong>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.</p> <p><strong>Methods: &...

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Những tác giả chính:	Lucinde, RK, Mugo, D, Bottomley, C, Karani, A, Gardiner, E, Aziza, R, Gitonga, JN, Karanja, H, Nyagwange, J, Tuju, J, Wanjiku, P, Nzomo, E, Kamuri, E, Thuranira, K, Agunda, S, Nyutu, G, Etyang, AO, Adetifa, IMO, Kagucia, E, Uyoga, S, Otiende, M, Otieno, E, Ndwiga, L, Agoti, CN, Aman, RA, Mwangangi, M, Amoth, P, Kasera, K, Nyaguara, A, Ng'ang'a, W, Ochola, LB, Namdala, E, Gaunya, O, Okuku, R, Barasa, E, Bejon, P, Tsofa, B, Ochola-Oyier, LI, Warimwe, GM, Agweyu, A, Scott, JAG, Gallagher, KE
Định dạng:	Journal article
Ngôn ngữ:	English
Được phát hành:	Public Library of Science 2022

Miêu tả
Tóm tắt:	<p><strong>Introduction: </strong>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.</p> <p><strong>Methods: </strong>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.</p> <p><strong>Results: </strong>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.</p> <p><strong>Conclusions: </strong>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.</p>