HIV Transmission Risk Highest Early in Infection
Posted by pozlife on March 11, 2007
Canadian researchers said Monday that a genetic analysis of newly HIV-infected patients showed that almost half of the infections occurred when their partners were also newly infected.
“The early infection stage can be entirely asymptomatic,” said study leader Dr. Mark Wainberg of Montreal’s McGill AIDS Center. “This is why people who are recently infected may not know it, and will probably often test negative by conventional antibody screening.”
“Hence, we must do a much better job of identifying recently infected people if we are to be able to counsel them to modify high-risk sexual behavior and desist from transmitting the virus,” Wainberg said.
Wainberg and colleagues from several Canadian hospitals and health centers studied HIV transmission among infected patients in Quebec through phylogenetic analysis. This analysis recorded viral mutations to help map out a family tree of the virus and provide an estimated time of infection. Based on the viral strains’ limited mutations, the study found that 49 percent of the early infections were clustered in a way suggesting transmission by people who were themselves in the early stages of HIV infection.
Because newly infected people have many copies of HIV in their blood, or a higher viral load, they have a higher risk of forward transmission.
The study, “High Rates of Forward Transmission Events After Acute/Early HIV-1 Infection,” was published in the Journal of Infectious Diseases (2007;195:951-959).
[This summary provided by the CDC National Center for HIV, STD, and TB Prevention | Reuters | March 5, 2007]
Source: HIV Plus