Scientists Probe How HIV Infection Turns Into AIDS

(Page 3)

"In an individual with advanced disease, if you look at the number of cells that are actually infected [with HIV], we are talking less than 1 percent," he said. "But, in reality, that individual may have lost 20, 30, 50 percent of his immune cells."

Rodriguez also questioned the importance of multiple strains of HIV infecting the same immune cell. "The data that we already have in hand shows that multiple infection is relatively infrequent," he said.

The bottom line, according to the Cleveland expert: As with any mathematical model, this one needs to be tested out in the laboratory.

Wodarz agreed that experimental verification is necessary, but he said mathematical disease models more often than not prove to be right.

In fact, he said, it was just such a model that led scientists to discover that HIV never stops evolving in the body -- even during infection's years-long asymptomatic phase.

"In HIV, mathematical models have led to great progress before," Wodarz said.

More information

To find out more about HIV/AIDS, head to the U.S. National Institute of Allergy and Infectious Disease.