As New York City public health officials Tuesday attempted to track down the sexual contacts of a man with what has been termed a “super-strain” of HIV, other AIDS experts questioned why such an uproar has emerged over a single case.
New York officials had announced Friday that they had identified a newly infected individual, a man in his mid-40s, who had a strain of the virus that was resistant to three of the four classes of anti-AIDS drugs and that progressed rapidly to full-blown AIDS in months, rather than years, as is typical.
Because the man had a large number of homosexual contacts, Health Commissioner Dr. Thomas R. Frieden raised the specter of an outbreak that could be substantially harder to treat.
Concern increased Monday when San Diego County Public Health Officer Nancy Bowen said an unidentified man in San Diego was infected with a virus with a “similar molecular makeup.” On Tuesday, physicians in Massachusetts also said they might have seen similar cases.
But some experts cautioned that there still was not enough information to determine whether the cases represented an evolution of the disease.
“I’m not ready to call this a super-bug,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and a leading AIDS expert. “We are having extrapolations that go beyond the data that are available....Show me 10 people that have this, and then I will say, ‘Whoa, we’ve got a problem here.’ ”
Dr. Irwin Chen, director of the UCLA AIDS Institute, echoed Fauci’s conclusion. “This is something we need to be aware of ... [but] we’d have to see a cluster or group in the same area before it becomes more of a serious issue.”
In 2001, a University of British Columbia physician reported two patients infected with a highly resistant strain of HIV that rapidly progressed to AIDS. But the patients apparently didn’t transmit the virus to anyone else.
New York officials said Tuesday that they were unaware of the British Columbia cases.
The latest case began in December, when the New York man went to a clinic run by Dr. David Ho of the Aaron Diamond AIDS Research Center in Manhattan. He had a low CD4 white blood cell count, an indicator that the infection was progressing rapidly.
The isolated virus was found to be resistant to 19 of the 20 drugs tested -- that is, to three of the four major classes of HIV medications. The infection, however, is responding to at least one and possibly two drugs.
Neither the rapid progression of the disease nor the drug resistance is in itself unique. About 1% of HIV patients are so-called rapid responders, whose infection progresses rapidly to AIDS. And 40% of the newly infected carry a virus resistant to at least one HIV drug. One study has shown that about 13% of those viruses are resistant to three classes of drugs.
It is the combination of the two factors that is unusual and alarming, said Dr. Ron Valdiserri of the Centers for Disease Control and Prevention.
But experts also noted that the man frequently used crystal methamphetamine during sex. The illicit drug severely compromises the immune system, possibly setting the stage for a more rapid progression. The drug destroys key white blood cells in the immune system, “the very cells that are crucial in fighting off HIV,” said Dr. Jonathan Fielding, Los Angeles County’s public health director.
New York officials said Tuesday that they had tracked down a dozen of the man’s sexual contacts and were testing them for HIV.
Much less is known about the San Diego case. Last fall a San Diego physician sent a blood sample to the testing company ViroLogic Inc. in South San Francisco, which found the virus to be multi-drug resistant. Officials were not particularly concerned until the New York announcement Friday.
After the announcement, ViroLogic compared the virus with others in its database and found that it was similar to the New York man’s and that in one other New York case.
But San Diego officials do not yet know who the patient is, so they do not know whether his infection is rapidly progressing.
The Massachusetts cases appear to be resistant to only two classes of drugs and so do not elicit as much concern.
Public health officials are divided on whether the New York announcement was premature.
“I really wish that more studies had been done and that we had a much better understanding of the properties of this virus before these alarming announcements,” said Dr. Warner Greene, director of the Gladstone Institute of Virology and Immunology in San Francisco.
Dr. Jeffrey Klausner, head of the sexually transmitted disease unit at the San Francisco Department of Public Health, said that even though he was not yet convinced that the virus really represented a new form of HIV, he supported the New York decision to publicize the HIV case.
San Francisco, he said, probably would have also released the information, though perhaps in a less dramatic format, such as quietly notifying physicians.
But Dr. Steven Tierney, San Francisco’s director of HIV prevention, said New York’s dramatic press release on the man’s condition amounted to scare tactics -- and might backfire.
“One model of prevention is to say that if we scare people enough, they’ll change their behavior,” Tierney said. “But 25 years into the epidemic, that hasn’t happened.... If some of your messages are phony and trumped up, then what reason do people have to respond to any of your messages?
New York officials are standing by their decision.
“We needed to warn people about this virus,” said Dr. Isaac Weisfue, deputy commissioner of the New York City Department of Health and Mental Hygiene. “We’re here to prevent virologic outbreaks, not just to report on them and study them.”