somewhat good news -- the "super AIDS" strand story seems to have been overreported, somewhat hysterically, and the strand itself is not new.
AIDS Case in N.Y. May Not Be a Harbinger of Supervirus
Drug-Resistant HIV Strain Shows Similarities to Virus in Canadian Patients Who Were Successfully Treated
By David Brown
Washington Post Staff Writer
Saturday, February 19, 2005; Page A09
The virulent and highly drug-resistant case of AIDS recently found in a New York City man is similar in some ways to two Canadian cases that appeared in 2001 and did not lead to the spread of a "supervirus," as some fear may happen in New York.
The Canadian cases turned out to be readily treatable despite their worrisome features. The infected patients -- two men who had no contact with each other -- are alive and in good health, said the physician who treated them. He originally described the unusual findings two years ago in a medical journal.
"They have done well. Everything is fine. But they did get into the race with a bit of a handicap," said Julio Montaner, chairman of AIDS research at the University of British Columbia. He acknowledged, however, that the New York case was "more florid, with more resistance and the patient more sick" than his patients were, and their experience may not predict the fate of the New York man or the people he may have infected.
New York City's health commissioner, Thomas R. Frieden, announced a week ago that a man in his forties had advanced AIDS diagnosed in January, 20 months after he had tested negative for HIV. Tests on the virus in his blood showed it was resistant to three of the four families of anti-retroviral medicines.
The man, who is gay, reportedly had more than 100 sexual contacts over the past six months, including many anonymous partners he met through the Internet. He engaged in unprotected intercourse while under the influence of methamphetamine, also known as "crystal." At the time he tested HIV-positive, his CD4 cell count -- a gauge of the health of his immune system -- was lower than 100, a sign of advanced AIDS. A normal CD4 cell count is more than 650, and U.S. patients generally are infected 10 years before the CD4 count drops that low.
The appearance of galloping AIDS and triply resistant virus in the same patient raised the possibility that a previously unseen, supervirulent strain of HIV had emerged. Worrisome under any circumstances, the appearance of such a pathogen in the subculture of drug-using gay men, in which anonymous sexual encounters are common and safe sex practices are rare, is especially frightening.
Public health officials are urgently trying to find the man's partners. As of last week, at least two had come forward. One has been infected for years, is on treatment and could not have gotten the virus from the man with the recent diagnosis. The other person refused to be tested for HIV and did not want to discuss matters further, said a person familiar with the case.
A strain of HIV with a very similar, although not identical, genetic profile as the one in New York was recently found in the archive of a national AIDS testing lab in California. The strain was originally reported to have come from a patient in San Diego.
Yesterday, however, San Diego County's public health officer, Nancy Bowen, said further research showed the patient was not from her area and she did not know where the patient was. New York City health officials have asked the commercial lab to help trace the source of that sample.
The British Columbia cases also involved a drug-resistant virus and disease that progressed rapidly -- although neither was as extreme as the New York case.
According to a report in the journal AIDS, one patient was infected by injecting drugs. His CD4 cell count fell from 680 in April 1999 to 240 in March 2001. The HIV in his blood was resistant to two of the three classes of anti-retroviral drugs available at the time.
In the second case, a man developed in January 2001 the flulike symptoms that are common immediately after HIV infection. He got the virus from sexual contact with a long-infected partner. By June, his CD4 count had fallen to 330, although it was back up to 510 in July. Steep CD4 declines followed by partial rebounds are common soon after infection; his case may have been an exaggerated version of that. His virus was also resistant to drugs in two classes of anti-retrovirals.
Both men were eventually put on three- or four-drug combinations, Montaner said this week. The growth of HIV is fully suppressed, and there is no virus detectable now in either patient's bloodstream, which is the goal of treatment. In both cases, their drug combinations include drugs in the same class as medications that their virus was resistant to in lab tests.
The New York patient was started on anti-retroviral therapy two weeks ago, and it is too early to tell whether it is working.
In practice, many patients respond well to drug combinations that include medicines in classes to which they are resistant, in lab tests. In addition, resistance can sometimes be overcome by giving higher doses or several drugs from the same class.
Curiously, when someone who has developed drug resistance after years of treatment stops taking anti-retrovirals, the HIV in their blood often becomes susceptible to the same drugs again.
The dramatic downhill course the New York patient took could have meant that his HIV was especially virulent, but it could equally reflect preexisting weakness in his immune system that has nothing to do with the strain of virus.
"We know the whole progression to disease is multifactorial. It has to do with the patient, and it has to do with the virus. We don't know yet why some viruses cause rapid disease and some don't," said Miguel Quiñones-Mateu, a virologist at the Cleveland Clinic.
If tracing of the New York man's partners leads to many newly infected people who have also had very rapid progression of disease, however, that will tend to implicate the virus, not the hosts.
Tests on the New York man's virus show it has a trait known as "dual-tropism." When HIV invades a cell, it attaches to a CD4 receptor on the cell's surface and to a co-receptor, labeled R5 or X4. Most HIV strains attach to one or the other co-receptor. The New York virus can use both -- an unusual but not unique ability.