Biologists at Bangalore's Jawaharlal Nehru Centre for Advanced Scientific Research recently discovered a new HIV strain in the southern Indian states. Led by Ranga Udaykumar, the researchers have been studying subtype C, the predominant strain of HIV in India, over the last three years. While analysing 115 samples, most of them from Karnataka, they spotted a recombinant strain between subtype B (HIV strain common in developed countries) and subtype C in three instances. The strain may just vanish, but there is also a possibility that it causes a new epidemic, cautions Udaykumar.

One year ago there were only eight official recombinants of HIV in India, now there are 22. The scientists had discovered a strain between subtype B and subtype C in 2004, sparking off interest in the genetic variation in HIV.

Recombinant HIV strains have surfaced in Thailand, China and West Africa. The discovery of a non-subtype C envelope in the new recombinant is also significant. "We are still two years away from concrete evidence regarding its pathogenecity,' says the scientist whose study is to be published in the June issue of the American journal AIDS .

"While TB took 20-40 years to gene rate drug-resistant varieties, HIV does it in a year or less,' says Udaykumar.