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4 results on '"Ochola LB"'

1. 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, 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, and Gallagher, KE

Subjects
Multidisciplinary, SARS-CoV-2, COVID-19, Prenatal Care, Antibodies, Viral, Kenya, Hospitals, Cross-Sectional Studies, Pregnancy, Seroepidemiologic Studies, Immunoglobulin G, Spike Glycoprotein, Coronavirus, Humans, Female, Pregnancy Complications, Infectious, Referral and Consultation
Abstract

Introduction 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. Methods 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. Results 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. Conclusions 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.

Published
2022

2. Seroprevalence of antibodies to SARS-CoV-2 among health care workers in Kenya

Author

Etyang, AO, Lucinde, R, Karanja, H, Kalu, C, Mugo, D, Nyagwange, J, Gitonga, J, Tuju, J, Wanjiku, P, Karani, A, Mutua, S, Maroko, H, Nzomo, E, Maitha, E, Kamuri, E, Kaugiria, T, Weru, J, Ochola, LB, Kilimo, N, Charo, S, Emukule, N, Moracha, W, Mukabi, D, Okuku, R, Ogutu, M, Angujo, B, Otiende, M, Bottomley, C, Otieno, E, Ndwiga, L, Nyaguara, A, Voller, S, Agoti, C, Nokes, DJ, Ochola-Oyier, LI, Aman, R, Amoth, P, Mwangangi, M, Kasera, K, Ng'ang'a, W, Adetifa, I, Kagucia, EW, Gallagher, K, Uyoga, S, Tsofa, B, Barasa, E, Bejon, P, Scott, JAG, Agweyu, A, and Warimwe, G

Subjects
QR180, virus diseases, RA
Abstract

Background Few studies have assessed the seroprevalence of antibodies against SARS-CoV-2 among Health Care Workers (HCWs) in Africa. We report findings from a survey among HCWs in three counties in Kenya. Methods We recruited 684 HCWs from Kilifi (rural), Busia (rural) and Nairobi (urban) counties. The serosurvey was conducted between 30th July 2020 and 4th December 2020. We tested for IgG antibodies to SARS-CoV-2 spike protein using ELISA. Assay sensitivity and specificity were 93% (95% CI 88-96%) and 99% (95% CI 98-99.5%), respectively. We adjusted prevalence estimates using Bayesian modeling to account for assay performance. Results Crude overall seroprevalence was 19.7% (135/684). After adjustment for assay performance seroprevalence was 20.8% (95% CrI 17.5-24.4%). Seroprevalence varied significantly (p Conclusion These initial data demonstrate a high seroprevalence of antibodies to SARS-CoV-2 among HCWs in Kenya. There was significant variation in seroprevalence by region, but not by cadre.

Published
2022

3. Non-O ABO blood group genotypes differ in their associations with Plasmodium falciparum rosetting and severe malaria.

Author

Opi DH, Ndila CM, Uyoga S, Macharia AW, Fennell C, Ochola LB, Nyutu G, Siddondo BR, Ojal J, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Band G, Maitland K, Kwiatkowski DP, Rockett KA, Williams TN, and Rowe JA

Subjects
Child, Humans, ABO Blood-Group System genetics, Plasmodium falciparum genetics, Case-Control Studies, Kenya, Genotype, Malaria, Malaria, Falciparum genetics
Abstract

Blood group O is associated with protection against severe malaria and reduced size and stability of P. falciparum-host red blood cell (RBC) rosettes compared to non-O blood groups. Whether the non-O blood groups encoded by the specific ABO genotypes AO, BO, AA, BB and AB differ in their associations with severe malaria and rosetting is unknown. The A and B antigens are host RBC receptors for rosetting, hence we hypothesized that the higher levels of A and/or B antigen on RBCs from AA, BB and AB genotypes compared to AO/BO genotypes could lead to larger rosettes, increased microvascular obstruction and higher risk of malaria pathology. We used a case-control study of Kenyan children and in vitro adhesion assays to test the hypothesis that "double dose" non-O genotypes (AA, BB, AB) are associated with increased risk of severe malaria and larger rosettes than "single dose" heterozygotes (AO, BO). In the case-control study, compared to OO, the double dose genotypes consistently had higher odds ratios (OR) for severe malaria than single dose genotypes, with AB (OR 1.93) and AO (OR 1.27) showing most marked difference (p = 0.02, Wald test). In vitro experiments with blood group A-preferring P. falciparum parasites showed that significantly larger rosettes were formed with AA and AB host RBCs compared to OO, whereas AO and BO genotypes rosettes were indistinguishable from OO. Overall, the data show that ABO genotype influences P. falciparum rosetting and support the hypothesis that double dose non-O genotypes confer a greater risk of severe malaria than AO/BO heterozygosity., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Opi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Published
2023
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4. Seroprevalence of Antibodies to Severe Acute Respiratory Syndrome Coronavirus 2 Among Healthcare Workers in Kenya.

Author

Etyang AO, Lucinde R, Karanja H, Kalu C, Mugo D, Nyagwange J, Gitonga J, Tuju J, Wanjiku P, Karani A, Mutua S, Maroko H, Nzomo E, Maitha E, Kamuri E, Kaugiria T, Weru J, Ochola LB, Kilimo N, Charo S, Emukule N, Moracha W, Mukabi D, Okuku R, Ogutu M, Angujo B, Otiende M, Bottomley C, Otieno E, Ndwiga L, Nyaguara A, Voller S, Agoti CN, Nokes DJ, Ochola-Oyier LI, Aman R, Amoth P, Mwangangi M, Kasera K, Ng'ang'a W, Adetifa IMO, Wangeci Kagucia E, Gallagher K, Uyoga S, Tsofa B, Barasa E, Bejon P, Scott JAG, Agweyu A, and Warimwe GM

Subjects
Antibodies, Viral, Bayes Theorem, Health Personnel, Humans, Kenya epidemiology, Seroepidemiologic Studies, Spike Glycoprotein, Coronavirus, COVID-19, SARS-CoV-2
Abstract

Background: Few studies have assessed the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers (HCWs) in Africa. We report findings from a survey among HCWs in 3 counties in Kenya., Methods: We recruited 684 HCWs from Kilifi (rural), Busia (rural), and Nairobi (urban) counties. The serosurvey was conducted between 30 July and 4 December 2020. We tested for immunoglobulin G antibodies to SARS-CoV-2 spike protein, using enzyme-linked immunosorbent assay. Assay sensitivity and specificity were 92.7 (95% CI, 87.9-96.1) and 99.0% (95% CI, 98.1-99.5), respectively. We adjusted prevalence estimates, using bayesian modeling to account for assay performance., Results: The crude overall seroprevalence was 19.7% (135 of 684). After adjustment for assay performance, seroprevalence was 20.8% (95% credible interval, 17.5%-24.4%). Seroprevalence varied significantly (P < .001) by site: 43.8% (95% credible interval, 35.8%-52.2%) in Nairobi, 12.6% (8.8%-17.1%) in Busia and 11.5% (7.2%-17.6%) in Kilifi. In a multivariable model controlling for age, sex, and site, professional cadre was not associated with differences in seroprevalence., Conclusion: These initial data demonstrate a high seroprevalence of antibodies to SARS-CoV-2 among HCWs in Kenya. There was significant variation in seroprevalence by region, but not by cadre., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.)

Published
2022
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