The Covid-19 pandemic has set the achievement of the United Nation's TB eradication target back with an estimated five years. Therefore, there is still an urgent need to prioritise TB services and research despite the huge challenges posed by Covid-19, according to researchers of the Immunology Research Group in the Division of Molecular Biology and Human Genetics (MBHG) of Stellenbosch University's Faculty of Medicine and Health Sciences.
Every year some 10 million people become ill with TB. In 2019, some 1,4 million people died from TB, making it the ninth leading cause of death globally. In South Africa there are approximately 500 000 new cases annually and TB caused nearly 60 000 deaths in 2019.
During 2020 TB services were restricted during the Covid-19 lockdowns. There was also less access to transport to reach health facilities. This meant fewer people were being tested and received treatment.
“In 2020 notification rates dropped dramatically by 25% to 50%," says Prof Gerhard Walzl, Head of the Division of Molecular Biology and Human Genetics. “So, there was a dramatic decrease in TB cases because fewer people are testing – not because TB has disappeared."
Infected individuals, who may not know they have TB, can infect others. “A single TB case can infect 10 to 15 people per year," says Walzl. “These individuals are only likely to report for testing when they become very ill. By then they will have a higher bacterial load and greater infectivity. The increased transmission will manifest in the next year or so. It has the potential to have a huge effect on the goal of eradicating TB."
“During 2020 the STOP-TB Partnership estimated that Covid has set us back five years in achieving the UN's Sustainable Development Goal TB eradication target of 2030," says Prof André Loxton, Deputy Director of the South African Medical Research Council (SAMRC) Centre for TB Research.
Lockdowns and the channelling of resources to fight Covid-19 also impacted on the research group's activities, requiring creativity and resourcefulness to keep projects going.
“Most of our research is funded by international grants," explains Walzl. “These projects are on tight timelines, with specific deliverables. Being barred from seeing participants in healthcare centres had serious knock-on effects. Losing grants due to inability to meet our targets will have a major impact on the group. For instance, most of the staff are paid by grants. They are highly trained individuals with skills acquired at great expense, so losing them would have a devastating effect on our ability to function – destroying years of building capacity and infrastructure."
Negotiation with funders and expanding the focus of some of the research to include Covid-19 enabled the projects to continue.
It was particularly important to understand the effect of Covid-19 on TB. “Early research suggested that people with latent TB might have poor outcomes if they contracted Covid-19," explains Walzl. “There is a different immune response to both and we didn't know the effects of Covid-19 on TB treatment outcomes."
Research is underway to diagnose TB early along with Covid-19. Questions include whether TB point-of-care tests, that measure immune-system protein markers, give false positive results in the presence of Covid-19, and also trying to understand the impact of Covid-19 infection on the outcome of TB infection and treatment.
“We responded to calls from funders to undertake Covid-19 research, but also looked at how we could bring Covid into the TB space; how we could apply our knowledge and experience to the new threat without drifting too far from our scope," says Loxton.
Although Covid has pushed the TB fight further onto the backburner, it has highlighted global interdependence and shown that some problems can't be solved by isolated pockets of research.
“There is more awareness of potential epidemics and the need to respond quicker with adapted, streamlined responses," says Walzl. “But, equally, there is more scepticism and misinformation regarding healthcare, which will impact on people's willingness to seek help for diseases like TB."
“TB is still seen as a problem of the developing world. TB research receives a fraction of the funding of diseases like HIV/AIDS. We need to change that," says Loxton. “We need bigger projects, moving faster to develop more sensitive, specific diagnostic tests, new drugs and more vaccine options. We need political will, funding and for all stakeholders to work together. Hopefully the momentum created by Covid-19 can be used for TB as well."
- Gerhard Walzl is a distinguished professor and head of the Immunology Research Group and Division of Molecular Biology and Human Genetics. He is also the executive head of the Department Biomedical Sciences at the Stellenbosch University's Faculty of Medicine and Health Sciences.
- André G Loxton is a professor and specialist scientist at the SAMRC. He is a principal investigator with the Immunology Research Group, and deputy director of the SAMRC Centre for Tuberculosis Research.