HIV tests in men should be accompanied also by examination of sperm in the semen. Because apparently the existing population of HIV in semen is different from the ones in the blood, so that it is not represented only by blood tests alone.
This difference was revealed when researchers compared the genetic code on the surface of HIV protein that exist in both types of these body fluids. Presumably, the differences arise from changes that occur in the genital tract where semen is produced.
Inside these channels, researchers have revealed two virus growth mechanisms that causes AIDS. Although both originated from blood, HIV will experience a change in accordance with the mechanism of growth experienced.
According to HealthDay, the first mechanism occurs in short term and produces viral populations which are relatively similar to more complex populations in the blood. Because of its rapid growth, there is no interaction with existing cells in the genital tract.
Interactions that occur in the second mechanism, which is the long-term growth in the genital tract. Before multiplying, HIV occupies T-cell or white blood cells that holds a role in the immune system at the cell level resulting a virus with different genetic code.
This study has not uncovered further whether the transmission affects the virulence and characteristics of the virus, and its influence on modes of transmission. However, these findings prove that blood tests alone do not represent the population of virus in semen.
This study was done by ateam from the University of North Carolina (USA), Edward Jenner Institute for Vaccine Research (England) and Baylor Pediatric Center of Excellence (Malawi). Review has been published online in the PLoS Pathogens journal August 19, 2010 edition.