Study Finds No Sign of Superinfection

A study of 33 HIV-positive couples who engaged in frequent unprotected sex found no evidence of HIV superinfection, the term given to infection by multiple variants of the virus, researchers from the Gladstone Institute of Virology and Immunology reported in July. In 28 of the 33 couples, one partner was infected with a strain of HIV that was slightly genetically different from the virus infecting the other partner. But despite numerous incidents of unprotected sex reported among the couples, none of the study participants were infected with a different HIV variant. A study of 30 HIV-positive single adults who engaged in unprotected sex with multiple HIV-positive partners also found no evidence of superinfection. The researchers recommend additional studies to determine how the body protects itself against HIV superinfection. 'The mechanisms preventing superinfection may include specific or nonspecific antiviral immune responses of viral interference,' they theorize.