Prevalence of IgG and IgM to SARS-CoV-2 and other human coronaviruses in The Democratic Republic of Congo, Sierra Leone and Uganda: A Longitudinal Study (preprint)

Objectives We assessed the prevalence of immunoglobulin G (IgG) and immunoglobulin M (IgM) against four endemic human coronaviruses (HCoVs) and two SARS-CoV-2 antigens, among vaccinated and unvaccinated staff at health care centres in Uganda, Sierra Leone, and the Democratic Republic of Congo (DRC). Methods Government health facility staff who had patient contact in Goma (DRC), Kambia District (Sierra Leone), and Masaka District (Uganda) were enrolled. Questionnaires and blood samples were collected at three timepoints over four months. Blood samples were analysed with the Luminex MAGPIX. Results Among unvaccinated participants, the prevalence of IgG/IgM antibodies against SARS-CoV-2 RBD or N-protein at enrolment was 70% in Goma (138/196), 89% in Kambia (112/126) and 89% in Masaka (190/213). IgG responses against endemic HCoVs at baseline were not associated with SAR-CoV-2 sero-acquisition during follow-up. Among vaccinated participants, those who had evidence of SARS-CoV-2 IgG/IgM at baseline tended to have higher IgG responses to vaccination compared to those SARS-CoV-2 seronegative at baseline, controlling for the time of sample collection since vaccination. Conclusions The high levels of natural immunity and hybrid immunity should be incorporated into both vaccination policy and prediction models of the impact of subsequent waves of infection in these settings.

The impact of the COVID-19 pandemic on the provision & utilisation of primary health care services in Goma, Democratic Republic of the Congo, Kambia district, Sierra Leone & Masaka district, Uganda (preprint)

Introduction This study aimed to determine whether the COVID-19 pandemic had an impact on the number of people seen at public facilities in Uganda, the Democratic Republic of the Congo (DRC) and Sierra Leone for essential primary healthcare services. Methods The number of weekly consultations for antenatal care (ANC), outpatient (OPD), expanded programme on immunisations (EPI), family planning (FP) services and HIV, for the period of January 2018-December 2020, were collected from 25 primary healthcare facilities in Masaka district, Uganda, 21 health centres in Goma, DRC, and 29 facilities in Kambia district, Sierra Leone. Negative binomial regression models accounting for facility level clustering and season were used to analyse changes in activity levels between 2018, 2019 and 2020. Results We found no evidence that the COVID-19 pandemic affected the number of OPD, EPI or ANC consultations in Goma. Family planning consultations were 17% lower in March-July 2020 compared to 2019, but this recovered by December 2020. New diagnoses of HIV were 34% lower throughout 2020 compared to 2019. Compared to the same periods in 2019, facilities in Sierra Leone had 18-29% fewer OPD consultations throughout 2020, and 27% fewer DTP3 doses in March-July 2020, but this had recovered by Jul-Dec. There was no evidence of differences in other services. In Uganda there were 20-35% fewer under-5 OPD consultations, 21-66% fewer MCV1 doses, and 48-51% fewer new diagnoses of HIV, throughout 2020, compared to 2019. There was no difference in the number of HPV doses delivered in 2020 compared to 2019. Conclusions The level of disruption appeared to correlate with the strength of lockdown measures in the different settings and community attitudes towards the risk posed by COVID-19. Mitigation strategies such as health communications campaigns and outreach services proved important to limit the impact of lockdowns on primary healthcare services.

SARS-CoV-2 antibody prevalence in Sierra Leone, March 2021: a cross-sectional, nationally representative, age-stratified serosurvey (preprint)

Background As of 26 March 2021, the Africa CDC had reported 4,159,055 cases of COVID-19 and 111,357 deaths among the 55 African Union Member States; however, no country has published a nationally representative serosurvey as of May 2021. Such data are vital for understanding the pandemic's progression on the continent, evaluating containment measures, and policy planning. Methods We conducted a cross-sectional, nationally representative, age-stratified serosurvey in Sierra Leone in March 2021 by randomly selecting 120 Enumeration Areas throughout the country and 10 random households in each of these. One to two persons per selected household were interviewed to collect information on socio-demographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. Capillary blood was collected by fingerstick, and blood samples were tested using the Hangzhou Biotest Biotech RightSign COVID-19 IgG/IgM Rapid Test Cassette. Total seroprevalence was was estimated after applying sampling weights. Findings The overall weighted seroprevalence was 2.6% (95% CI 1.9-3.4). This is 43 times higher than the reported number of cases. Rural seropositivity was 1.8% (95% CI 1.0-2.5), and urban seropositivity was 4.2% (95% CI 2.6-5.7). Interpretation IgM positivity was elevated as of March 2021 suggesting the second wave had not yet fully abated. Although overall seroprevalence was low compared to countries in the Global North (suggesting relatively successful containment in Sierra Leone), our findings indicate enormous underreporting of active cases. This is concerning because it may reflect significant underreporting of incidence and mortality across the continent. The low level of natural immunity is also worrisome in that it presents a very large population of susceptible individuals at risk for future variant waves in a country with only 0.2% of people fully vaccinated.