Figure. Three clusters of pandemic (H1N1) 2009 presymptomatic transmission in May 2009 in Osaka, Japan. All cases were confirmed as pandemic (H1N1) 2009 virus infection by real-time reverse transcription PCR. Squares indicate male case-patients, and circles indicate female case-patients. Colors of the squares and circles denote the similar or different schools the students attended.
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.