Zambia study casts doubt on the assumption that COVID-19 skipped Africa

A new study concluding out of Lusaka, Zambia last summer has found that as many as 19% (almost 1 in 5) of recently-deceased people tested positive for COVID-19. A new Boston University School of Public Health (BUSPH) study in Lusaka, Zambia's capital, challenges the common belief that Africa somehow "dodged" the COVID-19 pandemic.

The findings indicate that low numbers of reported infections and deaths across Africa may simply be from lack of testing, with the coronavirus taking a terrible but invisible toll on the continent.

Published in The BMJ, the study found that at least 15% and as many as 19% of recently-deceased people arriving at Lusaka's main morgue over the summer had the coronavirus, peaking at 31% in July. Despite most having had COVID symptoms, few were tested before death.

"Our findings cast doubt on the assumption that COVID-19 somehow skipped Africa or has not impacted the continent as heavily," says study co-author Dr. Lawrence Mwananyanda, a BUSPH adjunct research assistant professor of global health based in Lusaka. "This study shows that with proper diagnostics and testing, we can begin to identify the scale of COVID-19 in African countries such as Zambia. I hope this study will encourage African governments to look closer at the rollout of COVID-19 testing, as well as empower Africans to take proactive steps--such as wearing masks, physically distancing, and skipping handshakes--to protect themselves from COVID-19."

The findings also have important implications for global health decision makers, says study corresponding author Dr. Christopher Gill, associate professor of global health at BUSPH. "We will only end the COVID-19 pandemic if we ensure equitable access to a vaccine. Without the full data picture of the spread of COVID-19 in Africa, it will be impossible to ensure COVID-19 vaccines can get to the people and places that need it most," he says.

An estimated 80% of people who die in Lusaka pass through the University Teaching Hospital morgue. From June to September, polymerase chain reaction tests on 364 recently-deceased people found the coronavirus in 70 of them. While the majority of COVID-19 deaths in the United States and Europe have been in older adults, most of the deceased people who tested positive in this study were under 60 years old, including seven children. The researchers say that such a high proportion of pediatric deaths was particularly surprising given how rare COVID-19 deaths in children have been reported elsewhere.

Of the 70 people who tested positive, the researchers sought information about the symptoms they had been experiencing leading up to their fatal illness. "In nearly all cases where we had those data, we found typical symptoms for COVID-19, yet only 6 had been tested before death," Gill says. And among the 75% of deaths that occurred outside of the hospital, none had been tested before they died.

However, detecting the coronavirus in any country is no easy feat, much less in countries with limited resources. The researchers say Zambia's Ministry of Health has been very proactive and supportive of this and other COVID studies.

They're really grateful that we can provide them this data, and they can make informed decisions moving forward with this epidemic."

Dr. Lawrence Mwananyanda, Study Co-Author

The researchers were well-positioned to track COVID in Zambia. With funding from the Bill & Melinda Gates Foundation, they have been conducting the Zambia Pertussis/RSV Infant Mortality Estimation Study (ZPRIME) at the University Teaching Hospital morgue in Lusaka since 2017. In that ongoing study, nurses and physicians' assistants approach families who have lost a child between the ages of four days and six months for consent to conduct a nasal swab of the infant, and to offer grief counseling.

"Building studies such as this from scratch can take time and resources that can be difficult in the time needed to tackle the COVID-19 pandemic. We invested a lot of time and money and human resources to building infrastructure that allowed for that extensive surveillance," says study co-author Rachel Pieciak a research fellow at BUSPH. "So, what we've done was repurpose ZPRIME study capacity to focus on enrolling all deaths across all ages and testing for COVID-19."

Other research teams in similar situations might also be able to pivot in this way, Pieciak says. While many governments don't have the resources to effectively track COVID rates, "there's a lot of research money in places where we're not seeing really great COVID data," she says. "I would encourage other groups like us to think creatively about the resources that they have available, and to contribute to this effort."

For their part, the research team's findings will help inform COVID-19 efforts not just in Zambia, but many other countries. "What this study tells us is that when we looked for COVID-19 in Zambia, we found it--and there are a whole lot of other countries where there's similar lack of testing," says study co-author Dr. William MacLeod, research associate professor of global health at BUSPH.