The H1N1 flu pandemic is spreading not only in the Southern Hemisphere but also in such countries as the United States, China and Britain. The World Health Organization announced that as of July 10, the number of confirmed cases of infection in the world topped 100,000 in 142 countries. As of July 6, there were 429 deaths worldwide.

In Japan, as of July 15, the number of confirmed cases of infection topped 3,000, occurring in all the prefectures. Fortunately, no serious cases have been reported, perhaps thanks to early treatment of patients. But the possibility of a massive breakout during and after autumn cannot be ruled out. History shows that each new type of flu hits about 30 percent of the population in its first massive breakout.

The government should learn lessons from the mistakes it committed early on in executing programs to cope with H1N1 flu. It placed too much emphasis on efforts to block the virus at the nation's ports of entry. Such efforts have limitations because influenza has an incubation period of several days, and an infected person can transmit the virus on the day before symptoms appear. The system of having people first call fever- consultation centers to get advice on whether to go to designated hospitals did not work well.

In the event that the number of patients rapidly increases, care must be taken to prevent confusion at medical institutions. People with mild symptoms should stay home and receive treatment there. Only people with serious symptoms should be hospitalized.

Animal tests have shown that the H1N1 flu virus multiplies in the lungs and bronchial tubes — unlike ordinary flu virus. It is reported that Mexican patients who died of the new flu had serious pneumonia and that the damage to their lungs looked similar to that caused by the virus of the highly pathogenic avian flu.

Local governments and hospitals need to be well-prepared on how to best utilize a limited number of intensive-care units to treat people who have developed difficulty in breathing as a result of the new flu.