Infants born with HIV infection have a greater chance of survival if they receive early treatment - before they show signs of a weakened immune system or HIV-related illness, according to a report presented Tuesday at the 4th International AIDS Society Conference on HIV Pathogenesis, Treatment & Prevention.

A study of infants in Cape Town and Soweto in South Africa found that infants given immediate drug treatment had a significantly greater survival rate compared with children whose treatment was deferred.

The study, sponsored by the U.S. National Institute of Allergy and Infectious Disease (NIAID), was so successful that it was amended in 2007, ending enrollment in the deferred treatment group.

An estimated 2.3 million children are currently HIV infected, with around 600,000 new HIV infections in children each year. Without treatment half of all babies infected with HIV die before their second birthday.

“Children with HIV infection frequently show rapid disease progression within the first year of life due to their developing immune systems and susceptibility to other serious infections,” said Dr. Elias Zerhouni, director of the U.S. National Institute of Health, commented in a statement.

“This is the first randomized clinical trial that shows that infants treated before 3 months of age will do better than infants who have their treatment delayed,” Zerhouni pointed out.

The study of 337 babies, between 6 and 12 weeks old, was initially aimed at examining whether early antiretroviral drug therapy over a limited period would delay HIV progression.

Doctors had hoped that early treatment would allow a child’s immune system to develop and possibly allow the child to stop treatment for a period of time and avoid continuous therapy.

A preliminary data review in 2007 found a significant difference in survival rates and these interim results were forwarded to the World Health Organisation.

“The results of this trial could have significant public health implications worldwide because these findings will cause experts to consider changes in standards of care in many parts of the world,” said NIAID director Dr. Anthony Fauci.

The current standard of HIV care in many parts of the world is to treat infants with antiretroviral therapy, but only after they show signs of illness or a weakened immune system.

Medecins Sans Frontieres (MSF) said children were the “silent victims” of the global AIDS epidemic, with 9 out of 10 children with HIV infected through mother-to-child transmission during pregnancy, childbirth or breast-feeding, known as “vertical transmission.”

About 87 percent of children with HIV live in sub-Saharan Africa, with the vast majority beyond health services. Of the 540,000 children newly infected in 2006, the vast majority - 470,000 - live in Africa and only 700 in Europe or North America, said MSF.

MSF said vertical transmission of HIV is almost wiped out in wealthy countries by treating infected pregnant mothers and their infants with antiretroviral drugs within a few hours of birth.

The vertical transmission rate in wealthy nations was below 1 percent, compared with rates as high as 25 to 45 percent in poorer nations in Africa, said MSF.

The United Nations says close to 40 million people are infected with the AIDS virus and that treatment had dramatically expanded from 240,000 people in 2001 to 1.3 million by 2005.

In June, world powers at the Group of Eight (G8) summit in Germany set a target of providing AIDS drugs over the next few years to approximately 5 million people.