ISLAMABAD -- Pakistan has largely escaped the global HIV/AIDS epidemic, but health experts said on Friday that the country of 140 million people needed to take advantage of a window of opportunity to stop the disease from spreading.

Kristan Schoultz, country program advisor for the United Nations' UNAIDS agency in Pakistan, said the current low rates of HIV/AIDS infection presented the country with a chance to beat the virus.

"Unfortunately, I think this window of opportunity is probably very short," she told a news conference.

Schoultz cited the example of Pakistan's neighbor India, where the number of new cases has risen sharply and now only trails South Africa in total people infected.

Official data show Pakistan had an estimated 1,813 HIV/AIDS cases as of October 2001.

"We now know that the HIV/AIDS epidemic is rapidly evolving in south Asia. Fortunately the epidemic has yet to take firm hold in Pakistan, though there are signs that the nation is vulnerable in many ways," UNAIDS said.

"Pakistan's admirable response to AIDS so far will have to be strengthened and sustained over many years to come."

Factors contributing to the spread of HIV in Pakistan include poverty, power imbalances between men and women, low levels of education and literacy, and challenges in the areas of governance and human rights, the statement said.

Sexual contact and drug injecting are the most common modes of HIV transmission in Pakistan, Reuters quoted Schoultz as saying.