Seroprevalence of SARS-CoV-2 antibodies in Republic of Congo, February 2022

Abstract

In resource-limited countries, the lack of widespread screening masks the true situation of COVID-19. We conducted this study to assess SARS-CoV-2 spread by detection of specific antibodies and to determine associated factors. A population-based cross-sectional study was conducted. Subjects were tested for the presence of two antibodies (IgM and IgG) specific to SARS-CoV-2. Data collection was done using a smartphone with the KoboCollect application. Prevalence of antibodies was estimated with 95% confidence intervals. Logistic regression was used to determine factors associated with positive serological test. A total of 9,094 persons were tested in 4,340 households. The mean age was 30.18 ± 18.65 years, 46.5% male. The overall seroprevalence (prevalence, 95% CI) of SARS-CoV-2 antibodies was (48.2% [47.2%–49.2%]). Being vaccinated, having been in contact with a COVID-19 patient, being older than 50 years, living in a union, having secondary education and having tertiary education were factors independently associated with the likelihood of having anti-sars-CoV-2. We estimate in February 2022 that 48% persons had antibodies against the COVID-19 virus, more among those vaccinated. Vaccination intensification in low prevalence departments will reduce the risk of new outbreaks.

High pre‐Delta and early‐Omicron SARS‐CoV‐2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

“…Although lower, the 76.5% seroprevalence reported in Kenya by Awandu et al greatly surpasses PCR confirmed cases 25 . A 2022 rapid‐assay based survey in the Republic of the Congo reported a much lower seroprevalence (48.2%) 15 . This result is consistent with the aforementioned 2021 study in the country and, as per the results presented, reflects an exponential increase in infections from 31.8% to 48.2%.…”

“…In contrast, studies in the DRC have found seroprevalences ranging from 48% 12 to 70% 13,14 . A similar phenomenon has occurred in neighboring countries such as Republic of the Congo, 15 Cameroon, 16 Gambia, 17 Somalia, 18 Uganda, 12,14,19 Tanzania, 20 Nigeria 12,21,22 and Kenya, 23–25 where growing evidence indicates pandemic burden has been grossly underestimated.…”