Could one pill a week end TB?
TB kills more South Africans than any other disease. Now, Tembisa could hold the key to stopping the infectious bug in its tracks
In 2016, a tornado ripped through the community of Tembisa, northeast of Johannesburg. The whirling funnel of wind sent debris hurtling into the sky, threatening to come crashing down on homes and businesses.
Tuberculosis made a much less dramatic entrance to the community, moving in with residents as soon as the township was first established 60 years ago at the height of apartheid.
It’s killed thousands ever since. Today, TB is the leading cause of death in South Africa, according to
Statistics South Africa’s most recent data from 2016. The World Health Organisation (WHO) estimates that 322000 people developed active TB in the country in 2017.
Infections spread through the air, when a person with TB coughs, sneezes or spits.
One needs only to breathe the air in the vicinity of someone with active TB to be at risk. But not everyone who contracts TB will develop the active disease. Instead, the bacteria lie dormant for what could be years or even decades — what’s come to be called “latent infection”.
Today, research estimates that one in four people around the world is living with latent TB, a 2016 study published in the journal PLOS Medicine argues. In about 10% of people, this latent bug will develop into active TB, a 1999 report from the International Union Against Tuberculosis and Lung Disease says. But in some people, like those who live with TB patients or in poor, overcrowded conditions, this risk can be far higher. For instance, people living with HIV are 20 to 30 times more likely to move from latent to active TB, the WHO says.
For years, South Africa tried to stave off new TB cases by using one of the two drugs commonly used to treat active TB — isoniazid — to prevent it. But many people found the six- to nine-month antibiotic course too difficult to complete. Hiv-positive people had to take the treatment for up to three years — too long a period of time for most people, especially considering that these were otherwise healthy people.
Up to two-thirds of TB high-burden countries did not report using isoniazid preventative TB therapy widely, according to a 2015 WHO report.
But in 2016 a tornado wasn’t the only thing to touch down in Tembisa. The community was one of the first places to get access to a new onceweekly, three-month-long treatment to prevent TB. The two-drug combination still includes isoniazid but now pairs it with the antibiotic rifapentine, in a regimen known as 3HP — “3” for its duration (once-weekly doses for three months) and “H” and “P” for the abbreviations of the drugs it contains, INH and RPT.
In September 2018, the United Nations held its first high-level meeting on TB, committing the world to — among other goals — preventing 30-million new TB cases between 2018 and 2022. Preventative TB therapies such as 3HP remained at the heart of a recent The Lancet Commission on Tuberculosis report that recognises that our failure to implement TB prevention strategies is one of the key reasons we still have not made enough progress against the disease.
Unless we quickly tackle the seedbed of the epidemic — latent TB infection — we stand no chance of removing this health hazard from impoverished communities around the world.
The WHO has endorsed 3HP treatment to prevent active TB disease and health authorities in countries such as Canada are planning to implement the new 3HP treatment because it’s shorter and easier to tolerate for many — even in children as young as two years old or in people who are on antiretrovirals, including the newer drug dolutegravir, as was recently shown at the 2019 conference on retroviruses and opportunistic infections.
Many high-burden countries are in the process of revising their guidelines so that 3HP treatments can get to those in need. Pakistan, India and Indonesia are also exploring how to roll out the shorter preventive treatment under research conditions that will help them better understand how to roll it out nationally.
But many more nations and regions have yet to step forward.
In South Africa, the national department of health is exploring the introduction of 3HP to prevent TB for people with HIV and children living in Tb-affected households.
We cannot prevent tornadoes. We can prevent the global threat of TB, but any effort to do so must reach all of the poorest corners of the globe and our country, where the burden is great and the risk of disease is high.
Gavin Churchyard is the CEO for South Africa’s Aurum Institute and served on The Lancet Commission on TB. Follow the organisation on Twitter @Auruminstitute