HIV replicative capacity of the virus would have decreased

HIV has lost its replicative capacity since the 80s, according to Belgian researchers have published their work in the journal "AIDS."

Kevin Ariën, Institute of Tropical Antwerp (Belgium) Medicine and colleagues compared the replicative capacity of 24 HIV strains (12 isolated between 1986 and 1989 and 12 collected between 2002 and 2003) found patients n ' who never received treatment. 238 experiments on co-infection, 176 were concluded by a higher replicative capacity of old viruses from recent viruses.

The researchers then compared the replicative capacity of strains from patients with similar levels of CD4. For 9 of the 12 pairs, the oldest strain outweighed the latest.

The results for the 15 strains belonging to the same evolutionary branch (the only clade B) are similar to those of the rest of the study, say the Belgian researchers, who conclude that the observed attenuation effect is not due to differences between virus types.

According to them, "the attenuation of the virus over time could be caused by successive phenomena throttle during transmission."

"Several studies have shown that the replicative capacity of the virus increases the patient during the infection", they said. However, "when the virus infects a new person, its population is less diverse and so it has a lower than in the first individual replicative capacity. If the loss of capacity in the second person after the transmission is greater than the gain achieved in the first person just before transmission, several cycles attenuate the virus over time, "the researchers suggested.

"Although our findings need to be tested on a larger scale, we believe they can lead to a way of understanding the evolution of HIV," they concluded.