The standard methods to retreat tuberculosis (TB) is failing in low and middle-income settings, says study.
Researchers have called for improved access to rapid diagnostics for drug resistant TB, second-line TB treatment and antiretroviral HIV therapy.
Each year, between one in ten and one in five patients treated for TB see their disease return after failing, interrupting or relapsing from treatment.
This results in an estimated one million people in 90 countries being treated with an 8 month long regimen of five drugs. The therapy has been in use for over three decades and is recommended by the World Health Organisation.
But the study in Kampala, Uganda, of 140 HIV-infected patients and 148 HIV-uninfected patients found that the re-treatment TB regimen failed to work effectively in a significant proportion of patients - 26 percent of HIV-infected patients and 20 percent of HIV-uninfected patients.
Nearly a quarter of patients died, whilst 6 percent saw their TB disease return. Fatalities were particularly high amongst HIV-infected patients.
"Our study suggests that the recommended therapy for re-treating TB is failing as many as one in four people with recurrent TB in the developing world," said Edward Jones-Lopez, Assistant Professor of Medicine at Boston University School of Medicine.
The researchers believe that a number of reasons may be to blame. These include poor adherence to the drug regimen and the presence of drug-resistant forms of TB - including multi-drug resistant TB - some cases of which may have gone undiagnosed.
They call for improved access to rapid diagnostics for drug resistant TB, second-line TB treatment and antiretroviral HIV therapy.
The study has been published in the open access journal PLoS Medicine.