Those infected with HIV in the United Kingdom have one of the highest rates of resistance to anti-HIV drugs of anywhere in the world, prompting fears of a second wave epidemic of resistant virus, a new study claims in this weeks British Medical Journal.
The study authors are concerned that the large reductions in deaths and improvements to health since people with HIV were given combinations of drugs (combination antiretroviral therapy) may be compromised because of this.
Using national data on HIV positive cases, the researchers tested patients for resistance to the antiretroviral drugs before embarking on the treatment. Tests were conducted on 2,357 patients between 1996 and 2003 thus researchers could track if there were changes to resistance patterns as time went on.
They found that 335 people showed some degree of resistance to one or more antiretroviral drugs in total. Most of these people 257 were resistant to drugs within one class only, 44 cases showed resistance to drugs within two classes and 34 showed resistance to drugs within all three commonly used drug classes.
Overall, this equates to a 14 percent rate of resistance to one or more of these drugs among the group studied over the whole time period. The resistance had reached an estimated 19 percent for the most recent time period of 2002-2003.
The UKs 14 percent rate of resistance was considerably higher than the 7 percent estimate for chronically infected patients in the U.S., 6 percent in France and 10 percent elsewhere in Europe. Direct comparisons should be treated cautiously, however, as different studies have used different definitions of resistance. Using a more conservative definition of resistance (high level resistance to at least one drug) gives an overall estimate of 9 percent for the UK for the years 1996-2003, with the rate being 12 percent in 2002-2003.
The authors say, The United Kingdom has among the highest reported rates of primary resistance to HIV drugs worldwide. By limiting the therapeutic options for a significant number of patients, the secondary epidemic of drug resistant HIV represents a major clinical and public health problem.
Source: British Medical Journal