A major study has found that giving HIV patients an inexpensive antibiotic could save tens of thousands of lives.

The study of 3,179 newly-diagnosed patients in Uganda found that giving them a course of co-trimoxazole significantly reduced the death toll, the BBC reports.

Patients diagnosed with HIV usually begin their treatment with anti-retroviral drugs, which work by slowing down HIV infection.

But newly-diagnosed patients are also susceptible to infections and it is estimated that a quarter of people in sub-Saharan Africa die within one year of being diagnosed with HIV.

The study, published in The Lancet, found that giving people co-trimoxazole, as an addition to anti-retroviral drugs, lowered the death toll by 59 per in the first 12 weeks, and 44 per cent between 12 and 72 weeks.

The use of the antibiotic was also found to cut deaths from malaria by a quarter.

Although the treatment is already endorsed by the World Health Organisation, the scientists involved in the study said that it was not available to all who need it and that drug treatment programmes must move faster to keep up with developments.

Professor Charles Gilks, who led the study, said that questions over how well the treatment works were now “well and truly answered”.

He added: “Tens of thousands of lives can be saved by more universal use of the drug, costing just a few pence a day.”