Trends of SARS-CoV-2 antibody prevalence in selected regions across Ghana

Abstract

To estimate the level of community exposure to SARS–CoV–2 in Ghana, we conducted phased seroprevalence studies of 2729 participants in selected locations across Ghana. Phase I screening (August 2020) covered a total of 1305 individuals screened at major markets/lorry stations, major shopping malls, hospitals and research institutions involved in COVID–19 work. The screening was performed using a strip–in–cassette lateral flow type Rapid Diagnostic Test (RDT) kit that simultaneously and separately detected IgM and IgG antibodies against SARS–CoV–2 nucleocapsid protein. In Phase I, 252/1305 (19%) tested positive for IgM or IgG or both. Exposure rate was significantly higher among individuals tested at markets/lorry stations (26.9%) compared to those at Shopping Malls (9.4%). The 41—60–years age group had the highest exposure rate (27.2%). People with only a basic level or no formal education had a higher exposure rate (26.2%) than those with tertiary level education (13.1%); and higher in informally employed workers (24.0%) than those in the formal sector (15.0%). Phases II and III screening activities in October and December 2020, respectively, showed no evidence of increased seroprevalence, indicating either a reduced transmission rate or loss of antibody expression in a subset of the participants. The Upper East region has the lowest exposure rate, with only 4 of 200 participants (2%) seropositivity. Phase IV screening in February 2021 showed that exposure rates in the upper income earners (26.2%) had almost doubled since August 2020, reflective of Ghana′s second wave of symptomatic COVID–19 cases, which began in December 2020. The Phase IV results suggest that seroprevalence levels have become so high that the initial socioeconomic stratification of exposure has been lost. Overall, the data indicates a much higher COVID–19 seroprevalence in the Greater Accra Region than was officially acknowledged, likely implying a considerably lower case fatality rate than the current national figure of 0.84%. Additionally, the high exposure levels seen in the communities suggest that COVID–19 in Ghana still predominantly presents with none–to–mild symptoms. Our results lay the foundation for more extensive SARS–CoV–2 surveillance in Ghana and the West African sub–region, including deploying rapid antigen test kits in concert to determine the actual infection burden since antibody development lags infection.

The COVID-19 pandemic in the African continent

“…Nwosu et al [ 131 ] reported an antibody seroprevalence of up to 30% from sampling over 900 persons in Yaounde district, Cameroon, and this was more than 300 times the reported national case count from PCR testing. A study in Ghana with rapid kit detection of anti-nucleocapsid protein IgG and IgM reported up to 27% antibody seropositivity in populated areas such as lorry stations and markets, as compared to 10% seropositivity in shopping malls mostly patronized by the affluent [ 132 ], and these are much more than the reported infection rate from national case counts. A study among healthcare workers in Kenya found up to 20% IgG seropositivity against the SARS-CoV-2 spike protein in highly populous regions and about half that level of seropositivity in less populated areas [ 133 ].…”

Seroprevalence of SARS-CoV-2 Antibodies in Africa: A Systematic Review and Meta-Analysis

“… Overall seroprevalence of SARS-CoV-2 antibodies in Africa [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. …”

Modeling infections and deaths averted due to COVID-19 vaccination strategies in Ghana

“…We also assumed that for the base case scenario, at the beginning of the simulation, I =1, A=0, P=0, D=0, and V=0. We accounted for the age-specific seroprevalence of SARS-CoV-2 using estimates from Quarshie and colleagues in August 2020 ( 31 ). We, therefore, assumed that 17.5% of persons below 25 years, 43.6% of those between 25-64 years, and 18% of 65+ persons had been infected at the beginning of the simulation.…”

“…Studies on COVID- 19 vaccine hesitancy among Ghanaians reported that more than 35% of participants said they would not receive the vaccine because of concerns about vaccine efficacy and conspiracy theories ( 7, 10 ). Moreover, a seroprevalence study found that 19% of Ghanaians tested positive to anti-SARS-CoV-2 IgM or IgG or both in August 2020 ( 11 ). Thus, a majority of Ghanaians may be susceptible, and insight to effectively prioritize dispensation of limited vaccines would be the best approach to mitigating the pandemic.…”