A couple weeks following infection by HIV, the acute phase of HIV disease begins. This is characterized by flu-like symptoms at times, and a spike in the viral load in the body. This acute phase may last one or more months. In the past, this acute phase has been associated in a huge increase risk of spreading HIV, even when controlling for the spike in viral load. Some researchers have even claimed that a majority of HIV transmission occurs from people who have been recently infected. However, a recent study done at the University of Texas at Austin has shown that the extremely high level of infectivity estimated to be associated with acute infection is too high. 20 times too high to be more precise.
Not surprisingly, it can prove to be very difficult to estimate a person’s infectivity during HIV disease, especially during the acute-phase. This particular study had two parts. In one part, the researchers reanalyzed data that looked at acute-phase infectivity in heterosexual couples in Rakai, Uganda and controlled for additional elements that were ignored in previous studies (not specified). In addition to this analysis, they also estimated the risk of infection based on virus levels over the course of the acute phase.
While the results of this study were consistent in saying that the risk of transmission during the acute phase is higher than that of the chronic stage, the difference is much less substantial than previously believed.