Figures show that the number of deaths from the disease has fallen 47% to an 11-year low.

The fall in the death rate is due to the increased use of cocktails of drugs to treat the condition, the US Government said.

However, the rate of infection with HIV, the virus that can lead to aids, has remained steady, leading to calls for improved preventive measures.

Health statistics

Figures from America's National Center for Health Statistics for 1996 to 1997 showed that there were 5.9 deaths per 100,000 people - the lowest figure since 1987.

Campaigners call for better education about the disease

This takes the condition from the 8th most common cause of death in America to 14th.

The US health secretary Donna Shalala said the fall was due to people with HIV living longer.

"These new figures mean that new treatments have been very effective in extending the lives of people who already have HIV infection - but they do not mean that we have significantly reduced HIV transmission.

"Our ultimate goal is to prevent the estimated 40,000 new HIV infections that occur each year," she said.

Hilary Curtis, executive director of the BMA Foundation for AIDS, said preventing the disease remained important.

"It is important to understand that this fall in the AIDS death rate is due to improved treatment for people with HIV.

"There has not been a drop in the rate of spread of HIV and that means people need to continue to practise safe sex."

Record deaths

The mortality rate for the disease also fell last year, although the reduction followed a record year for aids-related deaths

In 1995 the death rate from AIDs was 15.6 people per 100,000, its highest ever level and almost three times Wednesday's figure.

"This is a dramatic step forward," said Daniel Zingale of AIDS Action, a lobbying group in Washington.

"What we're seeing is essentially a cutting in half of the numbers. That's remarkable progress."

The new combinations of drugs reduce the amount of virus present in the patient's blood.

However, it does not eliminate all traces of the virus and patients have been known to experience side-effects.

Treatment costs

The drugs are also expensive, which means only developed countries can afford to use them, even though the disease is more common in developing countries.

Mr Zingale said: "We must provide young people and women with the unvarnished facts about how HIV is spread as well as the sober truth about the new AIDS treatments.

"AIDS drugs cost $40 a day - condoms cost 40 cents."

Rene Durazzo, programmes director at the San Francisco AIDS Foundation, said people were still getting infected with the disease and prevention should be the priority.