Fears of AIDS 'Superbug' Eased
Viral Tests Show New York City Man Did Not Have a Uniquely Aggressive Virus
July 25, 2005 (Rio de Janeiro, Brazil) -- Fears of an AIDS superbug were
alleviated Monday when researchers reported that they have homed in on the
source of a New York City man's HIV infection.
Concerns had existed since February when officials from the New York City
Department of Health and Mental Hygiene announced that a middle-aged man had purportedly been infected with a new and unique
strain of HIV -- one that resists most medications used to treat HIV and
progresses to full-blown AIDS in a fraction of the usual time.
But viral testing shows that the man does not have a unique HIV strain, says
Gary Blick, MD, medical and research director of Circle Medicine in Norwalk,
Rather, the New York City man has the same viral strain as an HIV-infected
man in Connecticut, he says. The two men admit having unprotected sex with each
"The Connecticut patient's virus is a 99.5% match to the New York City
man. They're essentially identical," Blick tells WebMD.
Speaking at a meeting of the International AIDS Society, Blick says that the
52-year-old Connecticut man infected the New York City man with a potent viral
strain that is resistant to three of the four types of medications used to
Risky Behavior Blamed for Rapid Progression
One of the major reasons some health officials believed that a new AIDS
superbug was in our midst was that the New York City man developed AIDS in less
than 20 months, just two months after a positive HIV diagnosis was made.
Normally, progression from HIV to AIDS in an untreated patient takes 7 to 10
years, with death following months after that time.
But since the Connecticut man first tested positive for HIV in 1993, the
virus itself does not appear to be responsible for the rapid progression to
full-blown AIDS, Blick says.
So why did the New York City man get sick so quickly?
Most likely, his behavior is the culprit, Blick says. The New York City man
admitted not only to being promiscuous, but also to being a heavy user of
crystal methamphetamine, an illicit drug that lowers inhibitions and increases
risky sexual behavior.
Mark Wainberg, PhD, professor of medicine at McGill University in Montreal,
says multiple sex partners and repeated use of crystal "meth" may pack
a wallop to the immune system, facilitating infection with multidrug-resistant
Another indication that a fast-acting new strain of HIV was not behind the
man's rapid illness was a measurement of his CD4 cell count. Blick's study
shows that his CD4 cell count (an indication of disease progression) responded
to treatment, refuting the concept of a new aggressive strain.
Also, genetic susceptibility may have played a role in the man's condition,
Blick says. Because this type of supervirulent virus was seen in only one case
in February, some researchers had theorized that the man's individual genetic
susceptibility, not the virus itself, was responsible for its rapid
Wainberg tells WebMD that the study should end talk of a new AIDS superbug.
"It's a well-done analysis that shows the strains are virtually
identical," he says.