US researchers unravelled the DNA identity of the mutated virus after it was found in a New York man who is believed to have progressed to full-blown AIDS just months after becoming infected, rather than years, as is usually the case.

The unidentified man, aged in his late 40s, had had unprotected anal sex with multiple male partners and regularly took methamphetamine, or "ice" -- an outlawed stimulant that heightens sexual appetite and lowers inhibitions.

In a study published on Saturday in The Lancet, a team led by Martin Markowitz of the Aaron Diamond AIDS Research Center in New York, identify the 3-DCR virus as a mutated strain of the B subtype of HIV-1, the most widespread of the two main branches of AIDS virus.

Its genetic map shows it to have, unusually, a double option for penetrating human immune cells, able to latch onto its target via two docking points, called receptors, on the cell surface.

In addition, the virus' mutated shape means it is impervious to the three of the four classes of anti-retroviral drugs designed to stop the virus from replicating in the immune cell.

The other class of drug, a small and very expensive category of treatments called fusion inhibitors, which are designed to prevent the virus from docking to the cell, may make headway against it, according to the DNA analysis.

The patient went to his doctor on December 16, complaining of a sore throat and fatigue, the study says.

An HIV test was conducted, and it was positive. However, he had had five previous tests, between September 2000 and May 2003, and all were negative.

At a follow-up examination on January 13, he bore the hallmarks of full-blown AIDS -- severe weight loss, with the shedding of four kilos (8.8 pounds) in just three weeks, a sense of sickness, anorexia, sore throat and difficulty in swallowing.

Comparing his test results and record of sexual activities, the researchers believe the patient progressed from infection to AIDS in a timeframe of four to 20 months, a speed that has no parallel in the known history of the disease.

The virus was first reported at an AIDS conference in New York in February.

Its discovery was considered so important that the team alerted the city authorities, who began to trace the man's sex partners and held a press conference to urge the public to practice safe sex.

The emergence of a new, resistant strain of virus is a nightmare for AIDS campaigners, who worry it could negate the precious antiretroviral drugs that have turned HIV into a manageable if still incurable disease.

But the discovery also ignited controversy.

Other researchers blasted the alert as premature and some gay activists branded it hype.

Drug-resistant strains have sporadically popped up in the long history of AIDS, as have strains that swiftly cause transition to full-blown AIDS.

In addition, some people are highly susceptible to HIV while others can live almost problem-free for a decade or more before their immune system is compromised.

Markowitz's team stress it remains unclear how widespread 3-DCR virus is, how easily it can be transmitted, and whether some people may be genetically more vulnerable to it others.

But they also say the new virus is exceptional.

Normally, drug-resistant strains are less virulent -- they gain their resistance at the cost of their ability to replicate.

In this case, though, the agent -- but in laboratory conditions -- replicated as easily as non-resistant types.

"This case serves a reminder that HIV remains a frighteningly versatile foe, one that can mutate to escape immune attack or to acquire drug resistance with surprising speed," The Lancet said in an editorial.

"(...) Despite all the progress that has been made in developing new drugs, prevention remains the most effective strategy to combat HIV, especially efforts that target high-risk groups."

WASHINGTON (AFP) - Changes in sexual behavior helped more to slow the spread of HIV in the early 1990s than the ensuing introduction of AIDS therapy drugs, a study revealed.

"Since 1990 there have been important changes in Britain's social attitudes and awareness of HIV-1 and AIDS," wrote Dr. Deenan Pillay of UCL.

"Despite a very recent increase in high-risk behavior among men having sex with men, a significant increase in condom use has been reported since 1990, which could explain the equilibrium reached for the number of infections.

"Antiretroviral therapy may also have impacted on transmission rates, but our evidence does not demonstrate this," said Pillay.

Unlike what was generally believed about the AIDS epidemic in Britain, evidence in the study was found for "at least six larger sub-epidemics", contradicting "assumptions that the HIV-1 epidemic is composed of smaller, independent epidemics defined by risk group."

More than 57,000 people in Britain have been infected by HIV-1 since it was first identified in 1982.

HIV-1 is the most most common form worldwide of the AIDS virus, which falls into three groups --- M, N and O, according to different genetic characteristics. HIV-2 is the other form of the virus.

AIDS Virus Came to Britain Six Times, Study Shows

Mon Mar 14, 2005 05:42 PM ET

WASHINGTON (Reuters) - The AIDS virus came to Britain at least six separate times in the early and mid-1980s, not once as has been widely believed, researchers reported on Monday.

The team lead by University College London researchers found that HIV-1 subtype B -- that most commonly found in Britain -- spread quickly via at least six large transmission chains of men having sex with men.

There seems to be no geographic center for any of the epidemics, suggesting that men who carried the virus moved around the country, the researchers said in the report, published in the Proceedings of the National Academy of Sciences.

The virus was passed on less often by the 1990s -- most likely because men began using condoms, they added.

The HIV virus, which causes AIDS, affects 40 million people worldwide, with 14,000 new infections every day. There are at least six different subtypes, named A through E.

More than 57,700 people in Britain have been infected. The B subtype is transmitted mostly among men having sex with men. Elsewhere, HIV is most commonly transmitted among heterosexuals.

"Our study suggests that the HIV-1 subtype B epidemic currently circulating the U.K. is made up of at least six established chains of transmission, introduced in the early and mid 1980s," Dr. Deenan Pillay of University College London's Center for Virology said in a statement.

"This goes against the prevailing belief that one initial entry of HIV-1 was responsible for the spread of the epidemic."

For their study, Pillay and colleagues created a genetic family tree for HIV in Britain using samples taken from 1,645 British patients and 1,784 samples of subtype B from around the world.

Pillay said condom use may account for the slowed rate of new transmissions, and said his team found no evidence that HIV drug cocktails, which can suppress the virus and keep patients relatively healthy, had much of an effect on its spread.

SINGAPORE (AFP) - Singapore may introduce legislation empowering health workers to ask HIV patients for information on their sexual partners, a senior health official said in remarks published.

The lack of data is hindering the ability of the government's Communicable Disease Centre (CDC) to rein in the spread of new infections, Minister of State for Health Balaji Sadasivan was quoted as saying by the Today newspaper.

"The CDC is working blindfolded," Balaji told local media on Sunday.

Under existing regulations, HIV patients are not compelled to reveal the names of people they have been in sexual contact with. New regulations to fight the HIV/AIDS problem are expected to come into force as early as June.

Balaji had caused a stir last week when he suggested that one of Asia's most popular gay and lesbian festivals may be behind a sharp rise in the number of new HIV infections in Singapore.

He told parliament a record 311 people in Singapore had contracted HIV last year, 28 percent more than in 2003, adding that 90 percent of the people who contracted the virus were men, a third of them gay.

There are now more than 2,000 HIV or AIDS confirmed patients in Singapore.

Last year, the city-state included non-compulsory HIV testing as part of a routine medical checkup for pregnant women in a bid to stem the rise of new infections.

Fridae.com, which bills itself as Asia's largest website for gays, has hosted the increasingly popular Nation festival on the Sentosa resort island since 2001. More than 8,000 people attended last year's event.

Its chief executive Stuart Koe reacted angrily to Balaji's comments on the festival. He said they would fuel homophobia and he blamed inaction by the government as the main driver of the increase in HIV among gays.

But the legislation faces huge resistance from the ruling coalition's communist allies and opposition parties who are concerned about the availability of affordable drugs in India.

Domestic pharmaceutical companies and aid organizations working in developing countries have also expressed concerns.

The existing patent law has allowed drug makers to copy patented drugs as long as they use a different process. It has fostered a strong drug manufacturing industry in India for more than three decades.

The government argues, however, that patent recognition is an essential pre-condition for India's drug industry to further its own drug research and development or attract foreign partners.

The country is already the world's fourth-largest producer of medicines by volume but ranks only 13th by value, reflecting the very low prices of products in the local market.

India issued a presidential decree at the end of December but the change needs to be ratified by parliament within six months.

CONCERNS AT HOME AND OVERSEAS

Y K Hamied, chairman of drug maker Cipla Ltd., argued in a recent article published by the Indian Drug Manufacturers Association, that the amended law should make provision to grant compulsory licenses to Indian manufacturers to prevent monopolies, with the inventor given a suitable royalty.

He said the government should also have the freedom to grant automatic licenses to Indian companies for national health programs such as drugs for cancer, tuberculosis, malaria, asthma, hepatitis and HIV/AIDS.

Another local industry concern is that multinationals will be granted patents even when they make minor changes to drugs so that their patent lives get extended, thereby delaying the introduction of generic medicines.

Relief agency Medecins Sans Frontieres, or Doctors Without Borders, has said it is concerned about the availability of cheap medicines to patients in developing countries.

"We believe they (the amendments) will drastically restrict, perhaps even prevent, the production and supply of vital therapies by Indian pharmaceutical companies to other developing countries," Ellen 't Hoen, director of policy advocacy and research at MSF, said in a statement earlier this week.

MSF said about half of the 700,000 people receiving antiretroviral treatment for HIV/AIDS in developing countries relied on drugs from Indian generic drug makers.

Indian companies have also developed combination pills from drugs patented by different companies, which have become popular in HIV/AIDS treatment in developing countries. This was possible only because Indian law hitherto had no product patent constraints. (Additional reporting by Rosemary Arackaparambil)