Tuberculosis (TB) kills 1.6 million people every year and is one of the top 10 causes of death globally. And while it’s been kept under control in most places, more than 95 percent of cases and deaths are in developing countries, according to the World Health Organization (WHO).
Traditionally, it’s been difficult to prevent and treat TB in such regions, which is why Southwest National Primate Research Center (SNPRC) researcher Professor Jordi Torrelles, PhD, is focused on making a change. He developed a TB test that has been adapted for the challenging conditions typically encountered when diagnosing TB in developing countries.
“The way it’s done now, it takes 42 to 60 days before you get results from a TB test,” Torrelles said. “That’s before the patient is informed of results. When you factor that in, it’s more like 65 to 80 days from when the patient gives a sputum sample to when they learn whether they have TB.”
Torrelles traveled to Mozambique, Swaziland and South Africa in early 2019 to establish research collaborations for testing this cheaper, faster, easier way to diagnose TB. The current widely-used, commercially available TB test costs 608 USD. Torrelles’ improved version has a projected cost of just 9 USD.
What’s more, the current test does not indicate if a person is infected with drug-resistant strains of TB. Patients with these strains are even more difficult to treat, as they do not respond to the most commonly used TB drugs, requiring expensive, lengthy treatment. Torrelles and team started with what’s known as an “agar” test—which shows if the patient is infected with TB and whether the bacteria type or strain is resistant to three commonly used drugs for treatment—and developed a special color plate that can test for resistance to 11 drugs. They created two versions: one diagnostic, the other a treatment-tracking version to check if the patient is responding to the treatment.
In the past, results have usually been returned in 21 days for TB strains that can be treated with drugs, and up to 80 days for drug-resistant strains. If the SNPRC team’s new test plates are kept refrigerated, results can be seen as soon as three to 14 days, Torrelles said. And while many health care facilities in developing countries don’t have access to refrigeration, the improved diagnostic test doesn’t require it. Even if kept at room temperature, results can be interpreted between three and 19 days.
TB research is a top priority for scientists across the National Primate Research Centers (NPRC) network. Check out more ways we’re working to eliminate the disease for good.
