The World Health Organization says emerging diseases, climate change and chemical, radioactive and biological terror threats are putting all nations at risk. To mark World Health Day, WHO is urging greater cooperation among nations to better tackle international threats to health security. Lisa Schlein reports for VOA from Geneva.

Globalization has brought many benefits. It also has brought many risks. Health risks are among the most lethal. The World Health Organization says outbreaks of emerging and epidemic-prone diseases constitute one of the greatest direct threats to international health security.

WHO Director-General Margaret Chan says all nations are at risk. In a highly interconnected world, diseases spread fast and recognize no boundaries. Therefore, she says cooperation among nations is crucial. She says countries must share the responsibility for defending themselves against disease.

"In a sense, no one institution, organization or country can manage a public health emergency of international concern single handedly. So, we are beginning to see that," she said.

The World Health Organization reports disease is a much larger menace today than three decades ago and new diseases have emerged in unprecedented numbers. Diseases such as Ebola and HIV/AIDS, new forms of epidemic cholera and meningitis, and H5N1 avian influenza have killed hundreds of thousands of people.

Dr. Chan says better cooperation and collaboration among nations has resulted in positive developments in the global response to threats arising from bird flu. She says countries are making preparations to safeguard their citizens from a potential pandemic.

She warns there must be no let-up in these preparations.

"My sense is that we need to maintain our vigilance. We cannot let our guard down," she said. "The next pandemic will certainly happen. But, it is a real challenge. Nobody can predict the timing and nobody can predict whether it is going to be a severe or mild pandemic. And, no scientist can predict which avian influenza virus will ignite the next pandemic."

The World Health Organization says public health dangers also have economic consequences.

For example, fewer than 10,000 people became ill from SARS a few years ago. Yet, the SARS epidemic cost Asian countries $60 billion dollars in losses in the second quarter of 2003 alone.

Chief Executive of Cathay Pacific Airways, Philip Chen, steered the airline through the 2003 outbreak of SARS. He says no country can deal with SARS alone. Cooperation and transparency are crucial for combating this and other global diseases.

"If you do not tell people about the shortcomings even in baby food or in pain killer or a faulty engine or whatever," he said. "If you hide those facts ... If we do not report the SARS cases, than what would be the consequences. It would be far worse than coming clean and regaining the confidence of your consumers and actually building up, enhancing your reputation."

The World Health Organization says countries must take pre-emptive action against emerging and epidemic-prone diseases before they have a chance to become an international threat.