(Repeats, removing garble in lines 28/29)

By Kamil Zaheer

NEW DELHI, June 9 (Reuters) - The number of people with HIV in India, thought to have the world's highest caseload, could be lower than estimated, with infections possibly distorted by more than 2 million, officials said on Saturday.

The United Nations AIDS agency has said India has 5.7 million cases, followed by South Africa with some 5 million, but the officials said the high Indian figure could be due to faulty data-collection methodology.

A new population-based study, partly funded by the United States, indicated that India had about 3 million HIV-positive people at most, a senior official involved in New Delhi's AIDS control efforts told Reuters.

"It will definitely be lower than four million and most probably lower than 3 million cases," said the official, who asked not to be identified.

The survey findings were likely to show that India's HIV prevalence rate of 0.9 percent was too high and that the real percentage was close to half of that, he added.

Sujatha Rao, head of the state-run National Aids Control Organisation, agreed that the number could be lower.

The new data by the population-based study, called the National Family Health Survey, which took blood samples of 102,000 people from across the country, showed India had fewer cases than thought, she said.

"The figure is lower. How much lower, I don't know," she said.

Top Indian government and medical officials and international agencies such as the World Health Organisation (WHO) are expected to meet in New Delhi in the first week of July to announce the new HIV numbers.

NOT REPRESENTATIVE?

India has been recording its HIV epidemic through surveillance sites where, for four months a year, blood samples are taken from groups like pregnant women, men having sex with men, female prostitutes and intravenous drug users.

The overall number of cases and prevalence rates are deduced from those data. India has around 1,100 HIV surveillance sites, with more than half of them in six high-prevalence states in the south and northeast.

However, some officials said that surveillance sites gave an idea of trends within high-risk groups but did not allow experts to accurately estimate the overall national figure.

This could mean that the methodology was flawed as the sites are run by the state health sector, where poor people -- most affected by India's HIV epidemic -- go, causing the overall HIV number to be pushed upwards.

Another reason, said the senior official, was that surveillance sites covered female prostitutes working in brothels but not women who worked as prostitutes from home or from the streets, who "make up more than half the sex workers".

"These women have fewer customers than prostitutes in brothels and are less likely to be HIV-positive. This was not taken into account when figuring out HIV infection rates among sex workers," he said.

This year, India significantly increased its budget for fighting AIDS to 9.7 billion rupees ($238 million) for the fiscal year ending March 2008. AIDS campaigners said whatever the HIV figure, India could not relax in its anti-AIDS drive.

"We need to understand we have enough people in need of services and are not getting them. Whatever the figure is, it is large enough to be frightening," said Anjali Gopalan, head of Naz Foundation India Trust, a leading anti-AIDS voluntary group.

AlertNet news is provided by