Resistance to HIV drugs skyrockets

In 1996, only one percent of people with HIV in Britain were resistant to all three of the main classes of antiretroviral drugs. Today, that number has skyrocketed to about 13%, according to that nation’s Health Protection Agency (HPA).

It was the first report from the (British) National HIV Resistance Database, published in the HPA’s Communicable Disease Report (CDR) and shows that HIV drug resistance is increasing.

The increase in resistance is causing treatment to fail for many people who had initially responded well to the drugs.

Even more surprising was the percentage of people who had not yet received any drug treatment but who were infected with a strain of HIV that is already resistant. That figure increased from 10% in 1996 to 14% in 2001. Preliminary data indicates that the figure for 2002 may be as high as 21%. “This shows us that a number of people are contracting their infection from someone who is receiving or has in the past already received drug therapy,” the report noted.

The agency admits that the reality may be much worse than the figures show.

“We may not be aware of all patients whose drug therapy is not working, however those patients we have tested represent a small proportion (4%) of the 19,312 patients known to be currently receiving HIV therapy. Of these 4%, 21% had no level of resistance, 24% were resistant to one drug, 43% to two drugs and 13% to three types of drug.”

The analysis of the report is based on 2,025 resistance tests on individuals not on treatment (152 of whom were recently infected with HIV) and 4,577 tests on individuals taking treatment.

Resistance to antiretroviral drugs is caused by the virus’s ability to mutate in order to survive.  The rise of resistance to the drugs is similar to the crisis faced with antibiotics, in which bacteria have mutated into “superbacteria” resistant to most commonly used antibiotics.

SOURCE: Health Protection Agency (Great Britain), October 23, 2003.