[Novel influenza H1N1 pandemic: lesson learned].

The efforts made by the government of Japan and its people to prevent and control the spread of the disease and to limit its health impact had three major characteristics: (1) Suspension of schools in wide geographical areas particularly at the early stage of the outbreak. (2) High proportion of the infected persons who were given antiviral drugs. (3) High level of public awareness and personal hygiene such as regular hand washing. Although more research needs to be done, it seems fair to say that the three characteristics mentioned above contributed to Japan's globally one of the lowest mortality rate associated with the 2009 H1N1 influenza pandemic. Nonetheless, in the process of implementing prevention and control measures, the following four major lessons have been learned: (1) At the early stage of the outbreak, when the epidemiological information by definition is limited, control measures have to be based upon the worst case scenario. And as more information becomes available, measures have to be adjusted accordingly. (2) Risk communication is certainly one of the areas where more improvement have to be made, because some key messages did not reach the general public in a timely and accurate manner. (3) Essential is the development of "situation-based" intervention strategies, which take into consideration both infectivity and health impact such as mortality rate. (4) Decision making process is another area where there is more room for improvement, for example, clarification has to be made as to who are responsible for what.