With around 1.5 million deaths a year, Tuberculosis is the world’s deadliest infectious disease. Over the years, the infection has developed resistance against Rifampicin, a standardized drug that is used to treat Tuberculosis.

Rifampicin is the most effective drug against Tuberculosis, yet it no longer works against all strains. Therefore, it’s important to know as early as possible whether the strain that has infected a patient is rifampicin-resistant.

When a patient is diagnosed with a resistant infection, they are put on more improved drugs which are more expensive and have intense side effects.

Recently, a group of researchers at Rwanda Biomedical Centre (RBC) discovered that a standard algorithm that was used to diagnose provides faulty results.

Many patients were thus found to have resistance against Rifampicin while they actually didn’t.

According to the research, half of the patients diagnosed with Rifampicin resistance in fact had Rifampicin-susceptible.

Because of the false resistance diagnosis, these patients were treated without Rifampicin. They received a longer ‘second line’ treatment with higher toxicity drugs.

Researchers identified this false resistance problem to arise when patients have few bacteria in their sputum, whereby the current algorithm erroneously interprets insufficient DNA binding as evidence of resistance.

Dr Jean Claude Semuto, with his team of researchers, exposed a serious problem in Rwandan patients with tests that detect resistance to Tuberculosis drugs.

Half of the tested patients infected with resistant Tuberculosis were falsely diagnosed and did not get the correct treatment.

Based on their findings, the National Tuberculosis Programme in Rwanda changed its diagnostic algorithm and patients now receive proper care.

"Our new algorithm involves multiple testing and most of the time second results come out different which means the first results were false. Such patients are treated with Rifampicin and it works,” Semuto explained.

Number of patients of patients with resistant strain cut by half

Since January 2020 when the new algorithm was applied, Tuberculosis patients with Rifampicin-resistant strains have been cut by a half as of June 2020.

At Kabutare Hospital, one of three centers where Tuberculosis patients are treated, in Huye district, Dr Frank Cibunga who works at the hospital witnessed a change brought by the new algorithm.

"I can count Rifampicin-resistant cases we had since January because they are very few. It is not only good financially but also to our patients because Rifampicin has less harmful effects on their health,” he said.

Dr Semuto added that the new algorithm will help in treating patients in a faster, healthy way which might reduce a number of Tuberculosis patients.