Figure 1. Flow of each measure to identify infected individuals in Japan during the period April 28–June 18 and the number of individuals infected with Pandemic (H1N1) 2009 with international travel histories within 7 days of onset (n = 151).

Note: n is the number of individuals identified with Pandemic (H1N1) 2009 by each measure: 10 for Border Control Measures at Narita International Airport (4 from entry screening and 1 from quarantine in period I, 5 from entry screening in period II); 141 for Community Containment Measures (3 from health monitoring in period I, 5 from health monitoring and 133 from mandatory reporting in period II). The 24 missed cases are not shown as it is not known whether they were identified by health monitoring or enhanced surveillance. *Affected countries: Mexico, mainland U.S., Canada. **MHLW: Ministry of Health, Labour and Welfare of Japan.