With 2.1 billion airline passengers roaming the planet last year alone, infectious diseases are spreading faster than ever before, the World Health Organization said on August 23, calling on governments to follow revised rules for fighting health crises.

"Vulnerability is universal," WHO director-general Margaret Chan said in an introduction to the annual World Health Report, this year titled A Safer Future.

"New diseases are emerging at the historically unprecedented rate of one per year," said Chan.

A large part of WHO's attempt to protect global health has been through the revision of the International Health Regulations, which came into effect in June. The voluntary regulations govern how countries should report potentially dangerous health emergencies to the WHO.

While the regulations are meant to improve disease reporting worldwide, it is uncertain how much influence they actually have. For example, earlier this year, American officials anxiously tracked the European whereabouts of a US lawyer believed to have a highly dangerous form of tuberculosis.

Authorities eventually identified the roughly 127 people thought to have been exposed to his illness during two transatlantic flights.

But it was only after the lawyer had left Europe that US officials informed the WHO and other countries of the event - who were left powerless to act. The lawyer later turned out to have a less serious form of the disease.

"International public health security is both a collective aspiration and a mutual responsibility," Chan said.

While the governments of the WHO's 193 member states would ideally be the first source of information in any outbreak, that is often not the case. Nearly half of all of WHO's outbreak alerts come from the media and are then followed up with affected countries.

The annual report also urges countries to share viruses to help develop vaccines and to tighten domestic efforts to combat disease outbreaks.

But a continuing battle with Indonesia, the nation hardest hit by the H5N1 bird flu, has yet to be resolved. Indonesia has said it will send human bird flu virus samples to the WHO, but it has yet to fully share samples.

Jakarta has repeatedly demanded assurances that any pandemic vaccines developed would be affordable for developing nations. Instead of sharing viruses with the WHO, Indonesia has signed agreements with vaccine makers, promising to share samples in exchange for vaccine expertise.

China stopped sharing H5N1 specimens with the WHO for almost a year before finally sending samples in June, while Vietnam said it sent samples but encountered shipping road blocks.

In 1951, when the WHO issued its first set of health regulations to prevent the spread of diseases, the situation was stable, the report said. People traveled internationally by ship, slowing the spread of diseases around the world. New diseases were rare.

But today, high volumes of people can quickly travel worldwide, meaning an outbreak or epidemic in any part of the planet is only a few hours away from becoming an imminent threat somewhere else, the report said. Over the past five years, the WHO confirmed more than 1,100 outbreaks worldwide, such as cholera, polio and bird flu.

There are 39 new pathogens that were unknown a generation ago, including HIV/AIDS, Ebola hemorrhagic fever and SARS.