A new study conducted by scientists at the University of Ghana, has revealed that about 20 per cent of people living within Accra and Kasoa may have been exposed to the COVID-19 virus.
The study, which was led by scientists at the West African Centre for Cell Biology of Infectious Pathogens (WACCBIP) in collaboration with the Noguchi Memorial Institute for Medical Research (NMIMR), found that significantly more people have been infected by SARS-CoV-2, the virus that causes COVID-19, than Ghana’s 47,991 confirmed cases would suggest.
Professor Gordon Awandare, Director of WACCBIP, indicated that the study was conducted in public places including municipal markets and lorry stations in Accra and Kasoa.
The study also took place in shopping malls in Accra, COVID-19 testing centres and other research institutions/health facilities in Accra. Overall, 1,305 consenting individuals participated in the study.
Using a pre-validated antibody rapid diagnostic test (RDT), the scientists were able to determine exposure to SARS-CoV-2, by detecting COVID-19 antibodies in blood samples taken from the participants, it stated.
Antibodies are blood proteins produced by the immune system to counteract a specific foreign disease-causing agent.
According to the scientists, these tests were only able to detect exposure to the virus with about 70 per cent accuracy because antibodies wane after sometime and may be hard to detect in some individuals.
“What we are reporting is probably an underestimation because, first of all, these tests that we use are not 100 per cent sensitive so they could miss quite a good percentage of people who have been exposed,” said Professor Awandare.
It said though the Ghana Health Service was reporting about 47, 000 cases nationally, with an estimated prevalence in Accra of about 20 per cent, and a population in Accra of about 6 million, this brings the number of people infected in the past to about 1.2 million.
Professor Awandare together with other scientists also disclosed the evolution of the virus in Ghana following further genome sequencing.
It said evidence from the genome sequences also suggested that the virus had changed its genetic make-up and some unique variants could now be found in Ghana, which have not been identified anywhere else in the world.
“We have just completed the first detailed molecular analysis of SARS-CoV-2 viruses sequenced in Africa and, in two batches of samples—15 for the first batch and 31 in the second batch. We identified five clades of the virus that are circulating within Ghana,” said Dr. Peter Quashie, a Senior Research Fellow at WACCBIP.
“Because of the quality of our sequences, we were able to actually track and link the different samples to each other and see which samples likely had similar ancestry”.
“We were able to identify unique substitutions or genetic changes, in Ghana which have not been either identified elsewhere or are known stochastic mutations that occur in-country,” it said.
The scientists believed that the results of both studies provide evidence that COVID-19 was not in decline as current daily confirmed case numbers would suggest, but rather on the rise and spreading in communities.
“I think these are somewhat cautionary results,” said Dr. Yaw Bediako, a Research Fellow at WACCBIP, stated.
“We know these things can switch in an instant. So, we have to be vigilant and we have to be aware that COVID-19 is, indeed, circulating freely in our country and [that] our current testing protocols, which are focused on symptomatic people, will only capture a very small fraction,” it said.
The report said analysing the genetic structure of various strains of the virus, the scientists also found evidence of transmission from the Greater Accra Region, through the Central Region, to the Western Region.
“The most transmissible variants, according to the data, were found in Ayawaso, which was a hotbed for the disease when it first broke out in Ghana,” it stated.
Results of the seroprevalence study show that the exposure rate was higher among people tested at the markets and lorry stations (about 27 per cent) than those at the malls (around 9 per cent).
It indicated that the study also showed that differences in socio-economic status could determine risk of exposure to the virus.
“Having a higher level of education and a high level of income also significantly reduces your risk of being exposed compared to those who have lower levels of education and those who earn low incomes.”
“We also found that individuals working in the informal sector are at a two-fold increased risk of being exposed,” Dr. Peter Quashie said.
A majority of the participants who were found to have been exposed to the virus are between the ages of 41 and 60. A majority also work in the informal sector, many sampled from the markets and lorry stations.
Dr. Kofi Bonney, a Senior Research Fellow at NMIMR, cautioned that the virus was still circulating, thus all needed to be wary of that and adhere to the protocols strictly. Otherwise, what is happening in the Western world may surface here as well.”