Nations of the world today face common enemies in deadly pandemic diseases such as HIV/Aids and bird flu and unless there is close international cooperation in such battles, it is not hard to guess which side will emerge the winners.

Prime Minister Lee Hsien Loong, who said such diseases cross borders with ease and speed these days, warned that unless countries share information, combine their efforts and pool resources, future global health threats, which are yet unknown but possibly catastrophic, will triumph.

Speaking at a ceremony to mark World Health Day at the Suntec Convention City this afternoon, Mr Lee expressed disappointment that despite such perilous threats, scientific agencies today are still holding back information.

"We need to move away from this dangerous, oudated mindset. In the war on terrorism, necessity forced intelligence agencies in many countries to share information about terrorists threats and activities with one another. There is no reason why health agencies cannot develop a similar culture."

He noted that some countries have been reluctant to share viral samples for vaccine research because they want to ensure access to vaccines for themselves at reasonable prices.

Added PM: "Pharmaceutical companies assume big risks when funding research for vaccines. They need assurances that intellectual property arising from their research will be protected, so as to earn adequate return on their investments."

The challenge here is to strike the right balance between addressing the urgent public health needs of developing countries and protecting the intellectual property rights of the patent holder but so far, a completely satisfactory solution has not been found.

Citing the case of Indonesia as a possible model for sample and information sharing involving countries, Mr Lee said: "Both sides have recently reached an agreement for Indonesia to resume sending viral samples to the World Health Organisation, on the understanding that these will only be used for research purposes.

"At the same time, the WHO will set more transparent rules governing the sharing of these samples, mobilise financial support for vaccine stockpiles, and develop guidelines for the equitable distribution of vaccines to countries if a pandemic occurs."

He says Singapore's experience with the deadly Sars (Severe Affective Respiratory Syndrome) epidemic demonstrated the importance of rapid and transparent information exchange between countries and the WHO.

"In the early phase of the Sars epidemic, the failure of some governments to deal transparently with the problem contributed to the further spread of the virus within and between countries. It also hindered work to understand the nature of the disease and its causative agent, and to determine appropriate responses."

Stressing the need to build relationships of trust, Mr Lee said: "We face a common enemy which disregards national bureaucracies, politics and boundaries, and our response must be a united, global one."

Expressing grave concern about HIV/AIDS, PM Lee cited Sub-Saharan Africa, where some countries there see more than one-quarter of the adult population carrying the Aids virus. Describing this illness as a major concern affecting the whole world, he said that Asia is already emerging as the new epicentre of the HIV epidemic. An estimated 8.6 million people are living with HIV in Asia and there is an alarming trend of rising HIV infections in China and India, the world's two most populous nations.

In Asia, he added, the prevalence of HIV is highest in Southeast Asia, fuelled by unprotected sex and unsafe drug injections.

"Beyond a certain threshold, the HIV epidemic will explode. We are not there yet, but we must act now to control and prevent the spread of HIV/AIDS before it is too late," he warned.

Earlier in his speech, Mr Lee said that with international travel expanding, public health care has also taken on a trans-national perspective so that outbreaks spread quickly from one country to another.

Citing the Sars outbreak, he also pointed out that such pestilence can also wreak havoc on economies and societies.

Sars in Singapore in 2003 caused lives to be lost. International travellers, both tourists and businessmen, stayed away from Singapore. Even Singaporeans stayed indoors and this affected local businesses.

PM Lee said the government, employers and Singaporeans fortunately rallied behind the team of "courageous and dedicated healthcare professionals," and brought the outbreak under control.

On the need to translate words into action, Mr Lee stressed that the challenge is to bring plans on paper into fruition. He says that different countries are at different levels of development and thus have different resources and capacities, including infrastructures and technical expertise.

So it is important that action plans must take this ground condition into account.

"This can only come about when there is a constructive engagement based on mutual respect and trust. The solutions need to be adapted, customised and worked out together, and not be based on a single one-size-fits-all template," he emphasised.