摘要 : Influenza in the 2005/06 season (September 2005 - August 2006) in Sapporo, Japan, was characterized by mixed epidemics of the type AH3, AH1 and B viruses, and the predominant virus varied throughout the season. Epidemics of influe... 展开 Influenza in the 2005/06 season (September 2005 - August 2006) in Sapporo, Japan, was characterized by mixed epidemics of the type AH3, AH1 and B viruses, and the predominant virus varied throughout the season. Epidemics of influenza due to type B virus occurred late in the season, from May to June, which had not occurred before in Sapporo. In this report, we describe the epidemics of influenza in the 2005/06 season in Sapporo. In the Epidemiological Surveillance of Infectious Diseases in Sapporo, clinically diagnosed influenza cases per sentinel clinic per week exceeded 1.0 during week 52 of 2005, and increased thereafter. The number of cases per sentinel peaked at 23.9 in week 5 of 2006, and then decreased steadily until week 9. During weeks 10-11 and 20-21, the number of cases increased again and then decreased gradually. The height of the peak was the fourth highest of the most recent six seasons, but the totaLnumber of cases was the second largest, following only that of the 2004/05 season (Fig. 1). 收起