Two studies supported by the World Health Organisation have confirmed that antiretroviral therapy can drastically reduce the incidence of HIV-related opportunistic infections and deaths. The approach appears to be effective both for infected adults and children.

In recent years, antiretroviral therapy (ART) has been recognised as the best option to slow the spread of the virus and to prevent other infections from taking advantage of people's weakened immune system. There has also been robust evidence that the drugs can successfully be given in prevention to high risk populations to prevent them from becoming infected with HIV.

These two latest studies draw on past scientific literature to compare the risks of serious HIV-related infections in people who have already contracted the disease, before and after starting ART, in Africa, Latin America and Asia.

The researchers from Columbia University, the London School of Hygiene and Tropical Medicine, and McGill University, also estimated the global number of cases of infection that would have been prevented, and the costs saved, if therapy had been started earlier.

Large risk reduction in first year

In the first research, published in Clinical Infectious Diseases, scientists reviewed 126 studies involving nearly half a million HIV-infected adults, over a 20-year period. They found out that the risk of getting opportunistic infections such as tuberculosis, oral candidiasis, herpes zoster, toxoplasmosis or even bacterial pneumonias was higher for people with no access to antiretroviral therapy.

In contrast, they noted a reduction in incidence for all infections, except tuberculosis when people started antiretroviral therapy, in particular during the first year of treatment.

World Aids Day 2014
WHO says the use of antiretrovirals is essential in the fight against HIV/Aids and can reduce the risk of opportunistic infectionsReuters

In the second paper, also published in Clinical Infectious Diseases, researchers investigated if this was also the case for children. They conducted a systematic review and meta-analysis of 88 studies in the same regions and over the same time-period to evaluate the incidence and prevalence of 14 opportunistic infections, as well as the effects of antiretroviral therapy in 55, 679 HIV-infected children.

There again, the scientists found that there was a notable decrease in the risk of infections after starting ART – with the smaller impact being observed on bacterial sepsis and pneumonia, and varicella zoster.

More healthy, less costly

Both studies also highlight that many deadly infections could have been adverted if ART had been given earlier. The scientists estimate that 857,828 opportunistic infections could have been avoided in adults and 161,000 in children. This could have led to health saving costs of at least of $46.7m (£31.6m) per year for adults and $17m per year in children.

"We know that ART has a dramatic effect in reducing death rates as well as new HIV infections. These findings demonstrate that ART has the same effect in reducing the risk of serious HIV-related infections in adults and children – thus, further explaining the reduction in death rates. This reinforces the need to continually prioritise the expansion of access to ART", Dr Gottfried Hirnschall, director of WHO's HIV Department, concluded.