Report: AIDS virus most infectious in early stages

Schwartz AIDS workers have long known that the disease is most infectious during the early and late stages, but researches from London's Imperial College have found that it is even more infectious than previously thought. However, they found that those stages are shorter than previously thought, as well.

"We have always known that," said Dr. Bob Schwartz, director of The Bob Rauschenberg Center For Living. "It reaffirms what we already know. The problem is before people even know they have the disease. This does point out that it is extremely dangerous in terms of spreading when people don't know they're positive."

The results of the London study were released in the September issue of the Journal of Infectious Diseases. Researchers studied heterosexual couples in Rakai, Uganda.

Researchers found that primary infection, which is often a symptomatic, is an estimated 26 times more infectious and lasts about three months after the development of antibodies in blood serum.

"Once the immune system kicks in, it produces HIV antibodies, which slows it down," said Kris Thompson, supervisor of HIV and hepatitis prevention program with the Lee County Health Department. "People are always more infectious when they are first infected. That's why we do contacts and interviews, especially if they are newly infected. It all has to do with your immune system."

Thompson said it sometimes takes up to six months after infection to test positive for the disease because the test looks specifically for the HIV antibodies and those take time to produce.

The study said the late-stages of the disease is about seven times more infectious and kicks in between 10 and 19 months before death.

"It's a battle between the immune system and HIV," said Thompson. "The immune system holds it at bay but ultimately HIV wins and the immune system loses. Once that happens, you're at the end stages of the disease. At the end, it replicates so fast and the immune system is attacked so badly, it can't fight it off anymore."

Although AIDS was not formally recognized until 1981, some new research suggests it may be traced as far back as 1908. According to the Centers for Disease Control and Prevention, there are some 1.1 million Americans infected with HIV.