High Prevalence of Anti–Severe Acute Respiratory Syndrome Coronavirus 2 (Anti–SARS-CoV-2) Antibodies After the First Wave of Coronavirus Disease 2019 (COVID-19) in Kinshasa, Democratic Republic of the Congo: Results of a Cross-sectional Household-Based Survey

Abstract

Background On October, 2020, after the first wave of COVID-19, only 8290 confirmed cases were reported in Kinshasa, Democratic Republic of the Congo, but the real prevalence remains unknown. To guide public health policies, we aimed to describe the prevalence of SARS-CoV-2 IgG antibodies in the general population in Kinshasa. Methods We conducted a cross-sectional, household-based serosurvey between October 22, 2020, and November 8, 2020. Participants were interviewed at home and tested for antibodies against SARS-CoV-2 spike and nucleocapsid proteins in a Luminex based assay. A positive serology was defined as a sample that reacted with both SARS-CoV-2 proteins (100% sensitivity, 99.7% specificity). The overall weighted, age-standardized prevalence was estimated and the infection-to-case ratio was calculated to determine the proportion of undiagnosed SARS-CoV-2 infections. Results A total of 1233 participants from 292 households were included (mean age, 32.4 years; 764 [61.2%] were women). The overall weighted, age-standardized SARS-CoV-2 seroprevalence was 16.6% (95% CI 14.0-19.5). The estimated infection-to-case ratio was 292:1. Prevalence was higher among participants ≥ 40 years than among those ˂18 years (21.2% vs 14.9%, respectively; p˂0.05). It was also higher in participants who reported hospitalization than among those who did not (29.8% vs 16.0%, respectively; p˂0.05). However, differences were not significant in the multivariate model (p=0.1). Conclusion The prevalence of SARS-CoV-2 is much higher than the number of COVID-19 cases reported. These results justify the organization of a sequential series of serosurveys by public health authorities to adapt response measures to the dynamics of the pandemic.

Interest of seroprevalence surveys for the epidemiological surveillance of the SARS-CoV-2 pandemic in African populations: insights from the ARIACOV Project in Benin

“…In Natitingou, an incread-risk OR in symptomatic people was observed (OR = 1.33), although this association was not very clear (p = 0.25). (4,11,25,26).The seroprevalences we found in our 3 surveys fit also well with a recent meta-analysis showing a combined seroprevalence of 25% (95% C.I. [13% -39%] in West Africa (21).…”

“…Across the three surveys, the presence of symptoms in the past 3 months has not shown any relationship with positive serology, as observed in several other studies (4,(28)(29)(30)(31). This supports the hypothesis that the vast majority of the infected people have been asymptomatic…”

“…However, many SARS-CoV-2 seroprevalence surveys (following the WHO recommendations (20) ) published since the end of 2020 in different African countries, have now definitively disqualified this misconception (21) . The ARIACOV project (Support for the African Response against COVID-19) which carried out SARS-CoV-2 seroprevalence surveys in 6 West and Central African countries (Benin, Ghana, Cameroon, Democratic Republic of Congo, Guinea and Senegal) together with other initiatives helped to demonstrate that the virus has circulated widely on the continent (4,11,21,22) . All of these results show that, as highly useful as it is to understand the general dynamics of the COVID-19 pandemic, routine epidemiological surveillance in Africa exclusively based on the detection of infected cases by PCR (or antigenic RDT more recently) has proved unable to account for the true extent of the epidemic in the African context (limited screening capacity, proportion of asymptomatic cases probably overwhelming).…”

“…From the very first months of the COVID-19 pandemic, most of African countries implemented public health measures (2,3) to counter the spread of the virus, in particular sanitary cords, border closures and sometimes containment. These health governmental decisions were accompanied by sensitization campaigns on the wearing of a mask, social distancing measures, barrier gestures, hand washing, and also by increasing the capacities of national laboratories in terms of SARS-CoV-2 infection screening by Polymerase Chain Reaction (PCR) (4). The objective of this strategy was to interrupt the chains of transmission as quickly as possible, knowing that the capacity to handle severe cases in hospital was limited in most countries.…”

Characteristics and outcomes of patients with laboratory-confirmed COVID-19 during the first wave in Senegal

“…However, these data represent the lower extrema of estimation owing to the lack of testing and the high rate of asymptomatic or paucisymptomatic cases. Seroprevalence study performed in the Democratic republic of Congo has highlighted this point [13].…”