Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jul;63(7):1354-1365.
doi: 10.1111/trf.17449. Epub 2023 Jun 16.

SARS-CoV-2 seroprevalence among blood donors in Uganda: 2019-2022

Evan M Bloch  1 , Dorothy Kyeyune  2 , Jodie L White  1 , Henry Ddungu  3 , Swetha Ashokkumar  4 , Feben Habtehyimer  1 , Owen Baker  5 , Ronnie Kasirye  6 , Eshan U Patel  1 , M Kate Grabowski  1 , Ezra Musisi  2 , Khan Moses  2 , Heather A Hume  7 , Irene Lubega  6 , Ruchee Shrestha  1 , Mahnaz Motevalli  1 , Reinaldo E Fernandez  5 , Steven J Reynolds  4 , Andrew D Redd  4 , Hellen Wambongo Musana  6 , Aggrey Dhabangi  8 , Joseph Ouma  6 , Priscilla Eroju  6 , Telsa de Lange  9 , Mary Glenn Fowler  1 , Philippa Musoke  6 , Susan L Stramer  10 , Denise Whitby  11 , Peter A Zimmerman  12 , Jeffrey McCullough  13 , Jaiprasath Sachithanandham  14 , Andrew Pekosz  14 , Raymond Goodrich  15 , Thomas C Quinn  4 , Paul M Ness  1 , Oliver Laeyendecker  4 , Aaron A R Tobian  1
Affiliations

SARS-CoV-2 seroprevalence among blood donors in Uganda: 2019-2022

Evan M Bloch et al. Transfusion. 2023 Jul.

Abstract

Background: The true burden of COVID-19 in low- and middle-income countries remains poorly characterized, especially in Africa. Even prior to the availability of SARS-CoV-2 vaccines, countries in Africa had lower numbers of reported COVID-19 related hospitalizations and deaths than other regions globally.

Methods: Ugandan blood donors were evaluated between October 2019 and April 2022 for IgG antibodies to SARS-CoV-2 nucleocapsid (N), spike (S), and five variants of the S protein using multiplexed electrochemiluminescence immunoassays (MesoScale Diagnostics, Rockville, MD). Seropositivity for N and S was assigned using manufacturer-provided cutoffs and trends in seroprevalence were estimated by quarter. Statistically significant associations between N and S antibody seropositivity and donor characteristics in November-December 2021 were assessed by chi-square tests.

Results: A total of 5393 blood unit samples from donors were evaluated. N and S seropositivity increased throughout the pandemic to 82.6% in January-April 2022. Among seropositive individuals, N and S antibody levels increased ≥9-fold over the study period. In November-December 2021, seropositivity to N and S antibody was higher among repeat donors (61.3%) compared with new donors (55.1%; p = .043) and among donors from Kampala (capital city of Uganda) compared with rural regions (p = .007). Seropositivity to S antibody was significantly lower among HIV-seropositive individuals (58.8% vs. 84.9%; p = .009).

Conclusions: Despite previously reported low numbers of COVID-19 cases and related deaths in Uganda, high SARS-CoV-2 seroprevalence and increasing antibody levels among blood donors indicated that the country experienced high levels of infection over the course of the pandemic.

Keywords: COVID-19; SARS-CoV-2; Uganda; blood donors; epidemiology; serological testing.

PubMed Disclaimer

Conflict of interest statement

Disclosure of Conflicts of Interest

All authors are either are co-investigators, principal investigators or DSMB members on a Mirasol clinical trial funded by the US Department of Defense assessing the efficacy of pathogen reduction. AART reports personal fees from Ortho Clinical Diagnostics, Ashland Global and UptoDate, outside of the submitted work. EMB reports personal fees and non-financial support from UptoDate, Tegus and Health Advances outside of the submitted work. EMB is a member of the United States Food and Drug Administration (FDA) Blood Products Advisory Committee. Any views or opinions that are expressed in this manuscript are those of the author’s, based on his own scientific expertise and professional judgment; they do not necessarily represent the views of either the Blood Products Advisory Committee or the formal position of FDA, and do not bind or otherwise obligate or commit either Advisory Committee or the Agency to the views expressed.

Figures

Figure 1.
Figure 1.. Temporal trends in SARS-CoV-2 seroprevalence among Ugandan blood donors and COVID-19 vaccination in Uganda.
Proportion of donated whole blood unit samples positive from the MERIT donors (n=3517) for both nucleocapsid and spike antibodies (A), proportion of donated whole blood unit samples positive for either nucleocapsid or spike antibodies individually (B), and the proportion of Ugandans who had received ≥1 dose of COVID-19 vaccine (C). Manufacturer-provided cutoffs were used to determine positivity for SAR-CoV-2 seroprevalence. The shaded regions of panels A and B reflect Clopper-Pearson confidence intervals.
Figure 2.
Figure 2.. Nucleocapsid and spike binding antibody levels among Ugandan blood donors by year of donation.
Panel A shows the measured nucleocapsid and spike antibody levels for each year of collection among MERIT donors (n=3517). Samples are considered seropositive for nucleocapsid if antibody levels are ≥11.8 BAU/mL (vertical dashed line) and seropositive for spike if antibody levels are ≥17.7 BAU/mL (horizontal dashed line). Panel B shows the distribution of nucleocapsid antibody levels among samples that were above the cutoff for seropositivity. Panel C shows the distribution of spike antibody levels among samples that were above the cutoff for seropositivity. BAU/mL = Binding antibody units per milliliter.
See this image and copyright information in PMC

References

    1. Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21. Lancet 2022;399: 1513–36. - PMC - PubMed
    1. Bamgboye EL, Omiye JA, Afolaranmi OJ, Davids MR, Tannor EK, Wadee S, Niang A, Were A, Naicker S. COVID-19 Pandemic: Is Africa Different? J Natl Med Assoc 2021;113: 324–35. - PMC - PubMed
    1. Grasselli G, Greco M, Zanella A, Albano G, Antonelli M, Bellani G, Bonanomi E, Cabrini L, Carlesso E, Castelli G, Cattaneo S, Cereda D, Colombo S, Coluccello A, Crescini G, Forastieri Molinari A, Foti G, Fumagalli R, Iotti GA, Langer T, Latronico N, Lorini FL, Mojoli F, Natalini G, Pessina CM, Ranieri VM, Rech R, Scudeller L, Rosano A, Storti E, Thompson BT, Tirani M, Villani PG, Pesenti A, Cecconi M. Risk Factors Associated With Mortality Among Patients With COVID-19 in Intensive Care Units in Lombardy, Italy. JAMA Intern Med 2020;180: 1345–55. - PMC - PubMed
    1. Zhang Y, Luo W, Li Q, Wang X, Chen J, Song Q, Tu H, Ren R, Li C, Li D, Zhao J, McGoogan JM, Shan D, Li B, Zhang J, Dong Y, Jin Y, Mao S, Qian M, Lv C, Zhu H, Wang L, Xiao L, Xu J, Yin D, Zhou L, Li Z, Shi G, Dong X, Guan X, Gao GF, Wu Z, Feng Z. Risk Factors for Death Among the First 80 543 Coronavirus Disease 2019 (COVID-19) Cases in China: Relationships Between Age, Underlying Disease, Case Severity, and Region. Clin Infect Dis 2022;74: 630–8. - PMC - PubMed
    1. Burki TK. Undetected COVID-19 cases in Africa. Lancet Respir Med 2021;9: e121. - PMC - PubMed

Publication types