Possible New Strain of HIV Investigated
Resistance to Treatment and Rapid Progression to AIDS Give Rise to Superbug Fears
WebMD News Archive
New HIV Case a Wake-Up Call continued...
The potentially new strain of HIV is known only as 3-DCR HIV. And New York health officials say it has been identified in only one patient. This initially led some researchers to theorize that the man's individual genetic susceptibility, not the virus itself, may be responsible for its rapid progression.
But this idea came into question on Monday when it was announced that two more cases could be on the horizon.
In New York City, officials announced another man may be harboring a similar strain of the virus, while in California, a San Diego man has tested positive for a similar infection. According to published reports, this man was diagnosed with HIV last fall, around the same time the New York City man was diagnosed, though there is no positive link between the two.
And while experts say more testing is needed to determine if all three viruses are really the same, New York City health officials have issued a nationwide alert for doctors and health departments to retest all patients recently diagnosed with HIV and to look for the new strains.
Is a Superbug Really Here?
Despite the frightening possibilities, many AIDS researchers remain skeptical that a superbug is in our midst.
"Right now there are two very basic questions that are not being answered publicly, and they are intrinsic to how frightening this story really is," says Valentine.
The first question: Is the New York City man infected by more than one strain of HIV?
The second question: Did his CD4 cell count (an indication of disease progression) ever respond to treatment, even for just a short while?
Why is this information critical? Valentine says it's not unheard of for one person to be infected with two strains of HIV: one a "wild" or unmutated strain that progresses rapidly but responds well to drugs, and a second "mutated" strain that replicates slowly but does not respond to treatment.
Although the "wild" strain becomes the basis for initial diagnosis, once treatment is started that virus recedes, allowing the mutated virus, which does not respond to drugs, to come forward. If medication is then stopped in response to the drug-resistant virus, the "wild," rapidly progressing strain moves forward again.
It is this back-and-forth motion, says Valentine, that can make it appear as if one superbug is at work when it's really the work of two separate strains.
"If at any point the New York patient had responded to drugs, there's good reason to believe this dual diagnosis holds the key to what we are seeing now, " says Valentine.