A California man has been superinfected with two separate strains of HIV, picking up a wild-type strain months after he was initially infected with a drug-resistant form of the virus, researchers report in the May 2 edition of the journal AIDS. The patient was enrolled in a study of people initially infected with drug-resistant HIV, but researchers detected the second strain four months after the study began. The presence of the second distinct strain of the virus was confirmed with a genetic test that showed the second infection was not resistant to reverse transcriptase inhibitors. The initial infection was with virus that was resistant to the drugs. Superinfection had a negative impact on the health of the man, who was not taking anti-HIV drugs during the course of the study. His viral load increased from a stable level of 2,400 copies during the first four months of the study to over 200,000 two months later. His T-cell count dropped from about 800 at the time of superinfection to just 282 at the 11-month mark of the study.