In the mystery of the Scot and the disappearing HIV, it could be the vitamins that did it. But the culprit is far more likely to be an inaccurate blood test or a hidden viral infection.
Recently, a 25-year-old Scot living in London said in paid interviews with two British tabloids that he was “the first in the world to be cured of HIV”. Andrew Stimpson made his claims after testing HIV-positive, but later repeatedly testing negative.
But sceptical doctors say the “miracle cure” is more likely to reflect an initial false positive test result, or that the later negative results were inaccurate because Stimpson’s body was failing to produce the antibodies against HIV that the tests look for. Anecdotal reports of people spontaneously clearing themselves of HIV, which hides in the DNA of human cells, have never been substantiated. Dr Francois Venter, president of the Southern African HIV Clinicians Society, urged caution. “Maybe this was a laboratory or labelling mistake, or other error, or even an elaborate scam.
“The fact that he presented his case in the tabloids rather than through his London clinic, which is staffed by world-famous doctors, makes me very sceptical. We would like his story to be true, but the scientific community wants a lot more information from him before we believe this.”
The discrepancy between test results reportedly led Stimpson to attempt to sue the hospital where he was diagnosed. The hospital stands by the accuracy of its tests.
Antibody tests track traces of the virus by registering the body’s immune response. Detecting the virus itself requires a PCR test, which looks for viral genetic material. Although HIV antibody tests are among the most accurate tools available, false positive and false negative results do occur, albeit very rarely.
Antibody tests are calibrated according to the conditions in which they are used. The level of false positive results in a high HIV prevalent country such as South Africa would be lower than in a low prevalence setting. Local doctors say that in the United Kingdom, with its low HIV prevalence, three tests should be done to give a positive diagnosis of HIV infection.
It could be that Stimpson’s initial positive results were correct. In that case, the test may have registered a transient infection — he may have had exposure to HIV, but the virus failed successfully to infect him. One reason could be that he was being “vaccinated” by repeated exposure to HIV through sex with his HIV-carrying partner. This situation has been documented before, most famously in a group of Kenyan prostitutes who appeared to be resistant to HIV possibly as a result of being repeatedly “inoculated” by their clients.
Alternatively, Dr Adrian Puuren of the National Institute of Communicable Diseases says that Stimpson may still be infected with HIV, but that the antibodies against the virus have disappeared. Such situations have been described in medical literature, and researchers are still trying to understand why. A PCR test would tell if he was carrying the virus.
Stimpson said the original hospital had played Russian roulette with his life, by telling him that once he was HIV-positive he could have unprotected sex with his infected partner. Local doctors express surprise at such a statement, saying that even HIV-infected couples should practise safe sex in case they are infected with different strains.