Just days after news of a swine flu outbreak in Mexico, the deadly virus has been jumping borders to spread quickly to other parts of the world, as many other countries have reported suspected or confirmed cases.

On Monday, the World Health Organization (WHO) raised its global pandemic flu alert level from Phase 3 to Phase 4, which means the swine flu virus can cause sustained human-to-human transmission and "community-level outbreaks."

The immediate risk of the epidemic spreading quickly other parts of the world has sent a signal that, in an increasingly globalized world, infectious diseases must be addressed with concerted efforts from all countries.

As globalization deepens, the movement of people and goods is becoming all the more frequent and fast. Consequently, an infectious disease could spread quickly to other parts of the world from where the outbreak originates -- a new phenomenon in the spread of infectious diseases in a globalized world.

In the wake of the swine flu outbreak in Mexico, many countries have adopted emergency measures to ward off the virus. Other countries in the Americas which are in proximity to the epicenter of the virus have also acted promptly raced to take preemptive measures, so have many Asian, European and Middle Eastern countries.

It's the first line of defense against the disease that countries from around the world take measures at home to prevent the virus from spilling over. However, the cross-border spread of the viruses makes it a matter of urgency that the international community as a whole pools their wisdom and resources to meet the global challenge.

Timely warnings and alerts from international organizations on the development of the epidemic are also key to strengthening international coordination and providing technical advice. After the flu outbreak, The WTO has urged all countries to step up their surveillance of suspicious outbreaks of flu and severe pneumonia.

International financial institutions have lent a helping hand -- a new, encouraging phenomenon in global disease control.

The World Bank announced on Sunday that it would provide more than US$200 million in credit to Mexico to help it fight the swine flu. As a developing country, Mexico is in dire need of technological and financial assistance from the international community in combatting the epidemic. So the loans from the World Bank could not be more timely.

As the current swine flu outbreak has shown the trend of becoming a pandemic, countries from around the world should join hands and spare no efforts in controlling the disease. In efforts to fend off the threat of infectious diseases to mankind, countries should make long-term strategies for strengthening cooperation in scientific research and epidemic prevention.

Scientists from different countries have previously worked together to deal with epidemics such as severe acute respiratory syndrome, or SARS, and bird flu. The fresh outbreak of swine flu calls for closer international cooperation in research.

As no country in the world can escape unscathed from the effects of common threats mankind is facing -- ranging from climate change, the food crisis to contagious diseases, a joint response to global challenges is indispensable.

It must be stressed that in global efforts to curb infectious diseases, developed countries and international organizations should provide developing countries with necessary help. It is a natural obligation in global coordination to fight infectious diseases.