The risk of contracting HIV from a recently infected person may not be as high as previously believed, a new study in the journal PLOS Medicine has revealed.

Experts said that the findings could improve global efforts to prevent transmission of the deadly virtuous; and particularly bolster the strategy of treating patients with antiretroviral drugs before the onset of Aids.

The study, by researchers at the University of Texas, USA, notes that a few weeks after people are infected with HIV, they enter a month-long acute phase of infection when levels of the virus in the bloodstream spike.

If left untreated, this is followed by a decade-long chronic phase of infection that precedes Aids. The acute phase has been previously associated with elevated risk of spreading HIV, even higher than expected from the viral spike.

However, the new analysis finds that previous estimates of infectivity during this acute phase may not be too high.

"We found that people are less likely to spread HIV to others during this early stage than has been believed for many years,” said Steve Bellan, a professor at the University of Texas and lead researcher.

"Our new estimates imply that some novel strategies to control HIV may be even more effective”.

Estimating infectivity during acute-phase HIV is difficult, and only one study, involving heterosexual couples in Rakai, Uganda, has ever measured it directly.

"If newly infected people are not as infectious as previously believed, then we can be more optimistic about the global impact of HIV ‘treatment as prevention’ efforts,” said Lauren Meyers, a biology professor at the university, who authored the study.

In Rwanda, statistics from the Ministry of Health show that on average, one person is infected with HIV every 30 minutes; putting HIV/Aids prevalence 3 per cent.

By the end of 2013, the country had registered 48 per cent success in eliminating new infections and reduced the number of infected people from five to two per hour in the last five years.

HIV transmission from mother to child also reduced from 9 per cent in 2003 to 1 per cent in 2013. And the incidence of mortality and morbidity due to HIV/Aids has reduced by 3 per cent in the last ten years.

According to the head of HIV division at Rwanda Biomedical Centre (RBC), Dr Sabin Nsanzimana, they aim to promote condom use by 13 per cent, reduce new infections in children from 1,000 to less than 200 and increase the fraction of male adult circumcision from 13 per cent to 66 per cent by 2018.

About 700,000 men are expected to undergo non-surgical male circumcision by 2016 according to the Ministry of Health.