FIG. 1.

Influenza epidemiological and laboratory data for the period from January 2001 to March 2007 in Okinawa, Japan. The numbers of influenza cases identified at designated clinical sentinels in Okinawa are plotted in a broken line. The monthly numbers of influenza virus isolates recovered at the microbiology division of the Okinawa Prefectural Institute of Health and Environment are also shown. Weekly data from the source were converted to monthly values. Names of months are abbreviated by first letters.