The study is based on blood samples taken at regular intervals over several years from two women infected with HIV.

The number of children infected globally with HIV decreased by more than a quarter (26 percent) between 2009 and last year, but more than 90 percent of the 3.4 million children living with HIV are in sub-Saharan Africa.

Released on Wednesday, the annual UNAids report revealed there were 34.2 million people living with HIV last year, more than ever before.

This was ascribed to the life-prolonging effects of antiretroviral therapy (ART). An estimated 23.5 million of these people were living in sub-Saharan Africa, including 3.1 million children.

UNAids reported a number of other achievements including:

l An increase of 20 percent in just one year of people accessing ART (8 million).

l A 20 percent reduction in the number of people newly infected with HIV (2.5 million).

l A 24 percent decline since the peak in 2005 in the number of people who died from Aids-related causes last year (1.7 million).

Tuberculosis remained the leading cause of death among people living with HIV, despite it being a preventable and curable disease.

Young people aged 15 to 24 accounted for 40 percent of new adult HIV infections.

Globally, infection rates in women between 15 and 24 are twice as high as among men of the same age, with a young woman acquiring HIV infection every minute.

There is agreement that this is mainly due to their lower economic and sociocultural status in many countries where women and girls are disadvantaged in negotiating safer sex and accessing HIV prevention information and services.

The statistics are:

l HIV is the leading cause of death for women of reproductive age worldwide.

l Only one female condom is available for every 36 women in sub-Saharan Africa.

l More than one third of women aged 20-24 in low- and middle-income countries marry before they are 18.

l Nearly 40 percent of pregnancies worldwide are unintended.

l Globally, less than 30 percent of young women have comprehensive and correct knowledge on HIV.

l Two thirds of the world’s 796 million illiterate adults are women.

l Between 11 and 45 percent of adolescent girls reported that their first sexual experience was forced.

A failure by many countries to implement and scale up some of the basic programmes that aim to reduce HIV transmission was cited as a reason for the high rates of infection among those aged 15 to 24.

These programmes include voluntary medical male circumcision, behavioural change programmes, condom promotion and key programmes for those populations at higher risk of HIV infection such as teenagers, men who have sex with men and injecting drug users.

Some achievements were reported in sub-Saharan Africa, where nearly 6.2 million people are receiving ART, up from just 100 000 in 2003. The most dramatic progress was in SA, Zimbabwe and Kenya.

Last year, at least 300 000 people in SA were enrolled in treatment.

The report cautions that as more people start ART, concerns are growing about a possible increase in resistance to the drugs.

Low to moderate levels of transmitted drug resistance have been observed – increasing from 1 percent in 2005 to 3 percent in 2010.

Recent surveys reported that among those initiating treatment in low- and middle-income countries, about 5 percent had drug resistance.

SA is listed in the report as one of eight countries showing a rapid decline in new HIV infections among children – 49 percent.

Most of the adult HIV infections in sub-Saharan Africa resulted from unprotected sex, including paid sex and sex between men.

The report also makes a case for treatment interventions to become increasingly community based. A systematic review of treatment programmes in sub-Saharan Africa reported that, on average, 70 percent of people receiving ART from specialist clinics were still receiving treatment after two years.

On the other hand, a Community ART Group model initiated by people receiving ART in Mozambique, to improve access and retention on treatment and decongest health services, resulted in 97.5 percent of people receiving treatment after 26 months.

Dr Eric Goemaere, senior HIV/TB adviser for Médecins Sans Frontières in Southern Africa, said the world was finally past the half-way mark with HIV treatment, but almost one in two people did not have access to the medicines they needed to stay alive.

“The pace of HIV treatment scale-up and the funding needed to pay for it have remained virtually stagnant over the last year,” he said.

“If we’re going to reach all people who need treatment, we have to double the pace of scale-up and double the funds. Every day, more people need to be put on treatment than the day before. This can only be done if we see a dramatic increase in global support to fight this plague.

“In places where we work, we see how fragile the progress is that has been achieved over the last decade. Health ministries are working hard to implement the latest treatment recommendations and policies to get ahead of the wave of new infections, but they can’t do it alone.” - Health-e News Service