Public health experts called Friday for far-reaching measures against prison "incubators" of HIV, tuberculosis and hepatitis.

Inmates are much more likely to carry infectious diseases than the general public, they said, and will spread the deadly germs as soon as they are released.

Yet the response to the HIV, tuberculosis and hepatitis epidemics in prisons had been "slow and piecemeal", said Chris Beyrer, president of the International AIDS Society and lead author of a series of papers published by The Lancet.

"The majority of governments continue to ignore the strategic importance of prison healthcare to public health," he added.

The series was published ahead of Monday's opening of the 21st International AIDS Conference in Durban, South Africa.

It called for improvements in prison sanitation and overcrowding, the issuing of condoms, sterile needles to drug users, and for inmates to be vaccinated and given antiretroviral drugs against AIDS.

"Prisons can act as incubators of tuberculosis, hepatitis C, and HIV and the high level of mobility between prison and the community means that the health of prisoners should be a major public health concern," said Beyrer.

"Yet, screening and treatment for infectious diseases are rarely made available to inmates."

The series authors said HIV infection levels were 20 times higher among prisoners than civilians in western Europe, and about three times higher in parts of Africa and North America.

TB prevalence was higher in prisons everywhere.

At any given time, there are some 10.2 million people behind bars, both pre- and post-sentence, nearly 2.2 million in the United States alone.

An estimated 30 million people move in and out of prisons worldwide every year.

A major factor in virus and bacteria spread, the experts said, was injecting drug use among inmates, who often share needles.

- Zero-tolerance 'does not work' -

As the number of injecting drug users in prison has soared, partly because of the global "war on drugs", so has infectious disease.

According to recent estimates, "up to half of all new HIV infections over the next 15 years in eastern Europe will stem from increased HIV transmission risk among inmates who inject drugs", said a statement from The Lancet.

Furthermore, "imprisonment could be responsible for three-quarters of new tuberculosis infections among people who inject drugs, and around six percent of all yearly tuberculosis infections."

The authors said between 56 percent and 90 percent of people who inject drugs will be incarcerated at one point or another.

In parts of Europe, where 0.3 percent of the general population inject drugs, the percentage among inmates was 38 percent, while in Australia (0.2 percent) it was more than half.

But there was a dearth of treatment programmes for prison drug users. And only one percent of prisoners worldwide who need legal medicines to replace hardcore drugs such as heroin, receive it.

"Most strategies for dealing with infectious diseases in prisons focus on a zero-tolerance approach to drug users," said Beyrer. The fact that infection rates are still climbing confirms that this approach does not work."

The authors called for a reform of laws that criminalise drug use, and for non-violent addicts to be given treatment instead of jail time.

"The most effective way of controlling infection in prisoners and the wider community is to reduce mass imprisonment of injecting drug users," according to Beyrer.