A study of the rare strain of HIV reported in a New York City man last month that rapidly progressed to AIDS shows that the virus is particularly aggressive and better able to infect immune system cells than other HIV strains, The New York Times reports. The study, in the March 19 edition of The Lancet, shows that the virus can latch onto two types of receptors on the surface of CD4 cells--CCR5 and CXCR4; typically, HIV can attach to only one of the receptors. The virus also was shown to carry genetic mutations that make it resistant to all but one antiretroviral drug used to treat HIV disease. The study is based on the work of researchers at New York's Aaron Diamond AIDS Research Center, led by renowned AIDS researcher David Ho, chosen as Time magazine's Man of the Year in 1996 for his work on protease inhibitors.
The new strain of HIV was reported in a gay man in his late 40s who had likely been infected with the virus in the fall of 2004 but had progressed to an AIDS diagnosis within just a few months. HIV typically takes 10 years or more to progress to AIDS.
City health officials went public with the news of the man's infection in an effort to warn New Yorkers about the possibility of infection by the unusually virulent strain of the virus, particularly since the man reported recent unprotected sex with dozens of partners while using crystal methamphetamine. But some AIDS experts around the country were skeptical, saying that drug-resistant HIV is becoming more commonplace and that a single case study does not warrant widespread public concern. Some AIDS activists accused the New York health officials of trying to frighten sexually active gay men into limiting the number of sex partners they have and to use condoms.
City health officials say they publicized the case because although rapidly progressing HIV strains and those resistant to HIV drugs have been reported in the past, the combination of the two is unusual. New York health workers are still trying to track down the sexual partners of the man and test them to see if they've been infected. More than a dozen men have been identified and are in the process of having their blood samples screened.
"Only additional investigations will reveal whether this case is isolated or not," the researchers write in The Lancet. "Irrespective of the outcome, efforts to prevent HIV-1 transmission need to be intensified, with particular emphasis on the epidemic that is being propelled by the use of methamphetamine. However, in doing so, care should be taken to avoid punitive measures against the populations most vulnerable to HIV-1."