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HIV strains in India traced back to 1958

HIV strains in India traced back to 1958
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First Published: Wed, Dec 01 2010. 11 31 PM IST
Updated: Wed, Dec 01 2010. 11 31 PM IST
New Delhi: On World AIDS Day, even as governments and health experts cheerfully report a significant global decline in fresh cases, a band of researchers from India and Sweden report that before HIV (Human Immunodeficiency Virus) was identified for the first time in India among sex workers in Chennai in 1986, it was present for nearly three decades within the country.
The fact that the virus was dormant yet rapidly mutating, suggests that unlike what the decline in fatality numbers may lead us to believe, the dangerous potential of the HIV virus hasn’t gone away and could complicate efforts to develop a vaccine.
The study presented at an ongoing conference of the French-Indian Inter Academic Symposium on Infectious Diseases at the National Institute of Immunology here says that the earliest progenitor of HIV strains in India could be traced to 1958, and by the time HIV-AIDS had become lethally pandemic in the 1990s, different strains of HIV had quickly evolved to gain distinct identities even within the country.
India has the fourth largest population of people infected with HIV, which according to the latest estimates annually infects around 2.2 million, and is among the most resilient viruses.
Its intractability, experts suggest, is largely due to its ability to rapidly mutate and recombine with itself.
As of today, nearly nine sub-types of the virus circulate across the globe—each with different infection rates and prevalence.
India is dominated by the C sub-type, just as in Africa, and unlike the West, which is dominated by the B sub-type.
For instance, studies suggest that sub-type B is spread mostly by homosexual contact and intravenous drug use while sub-type C is significantly associated with heterosexual epidemics.
“What we’ve shown is how mutation has occurred within the HIV-1C strains in India. Though a vaccine is still elusive, most researchers believe that what will work against one sub-type may not be effective against another. Therefore, understanding the evolution of the strains in India is fairly important,” said Ujjwal Neogi, one of the lead researchers associated with the study and based out of St John’s Medical College, Bangalore.
For the study, Neogi along with researchers from the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, and the Karolinska Institute in Stockholm, collected blood samples from HIV patients in Karnataka, Punjab and Haryana, and compared it to a global database of HIV sub-types using bio-informatics tools, making it possible to establish that the virus existed in India from 1958.
“One of the key findings was the variability of the north Indian and south Indian strains. So we have some sense of how fast these strains have recombined and diverged among themselves to reach their present-day form. However, this rate might not necessarily hold in the future. It could be faster or slower,” said Neogi.
Interestingly, their analysis also suggested that the closest relatives of the Indian strains were in Tanzania, Zambia and Botswana, and quite distinct from the strains commonly found in China.
Independent experts suggest that though the study is immensely interesting, it might not affect or change the way scientists develop drugs for combating the virus.
“It’s very interesting and useful to trace the origins of the Indian sub-types,” said Shahid Jameel, a virologist at the International Centre for Genetic Engineering and Biotechnology, New Delhi, “but current drug approaches only look at different targets. At that level, sub-types don’t really matter, though it’s a different story altogether when developing vaccines.”
jacob.k@livemint.com
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First Published: Wed, Dec 01 2010. 11 31 PM IST
More Topics: HIV | AIDS | India | Healthcare | Video story |