Better screening takes the fight to drug-resistant HIV

[Guest guest]

Better screening takes the fight to drug-resistant HIV

T. V. Padma

5 July 2007. Source: SciDev.Net

[NEW DELHI] Scientists in United States have developed a faster and

cheaper method of screening for drug-resistant HIV.

Screening patients for drug-resistant strains of HIV helps doctors

choose the most effective drug combination, and helps prevent

treatment failure.

Treatment of patients infected with even small numbers of these

resistant strains can often fail, because the small resistant

populations survive drug treatment and continue the infection.

The increased availability of antiretroviral drugs to treat HIV/AIDS

in developing countries is expected to contribute to a global rise in

drug-resistant HIV strains.

Most developing countries across Africa and Asia cannot afford

current methods to detect resistant strains. In addition, current

methods are time-consuming, and not sensitive enough to detect small

numbers of drug-resistant HIV.

The new technique, developed by scientists at the University of

Pennsylvania School of Medicine in the United States, combines two

genetic methods. They first analysed DNA from seven HIV mutant

strains, including three showing resistance to many drugs. The

scientists then indexed the DNA sequences using a genetic marker as a

tag.

Using the index, they then characterised mutations in the drug

resistant strains using a DNA sequencing technique

called 'pyrosequencing' that can analyse millions of DNA sequences in

a single-day test. Thus, they were able to identify mutations that

contribute to drug resistance.

The researchers say the new method is faster and cheaper than current

methods because it can analyse multiple sequences in a short time.

The findings of were published last week (28 June) in Nucleic Acids

Research.

In a related development, Joanne Stekler and Coombs from the

Center for AIDS and STD in Seattle, United States, note that anti-

retroviral resistance is an emerging issue in resource-poor countries

with limited experience in dealing with resistant strains of HIV.

In an article in the June issue of the Journal of Infectious

Diseases, the authors suggest that treatment programmes should be

coupled with HIV drug-resistance surveillance programmes.

Reference:

Nucleic Acids Research doi:10.1093/nar/gkm435 (2007)

Journal of Infectious Diseases 96, 336 (2007)

http://www.scidev.net/News/index.cfm?

fuseaction=readNews & itemid=3730 & language=1