Real-time Surveillance of Pneumonia and Influenza Mortalities via the National Death Certificate System

Wan-Jen Wu

2009 Vol.25 NO.10

Correspondence Author: Jen-Hsiang Chuang


After the outbreak of 2009 pandemic influenza A (H1N1) in April of
2009, Taiwan CDC and the Department of Health Office of Statistics
cooperated to establish a real-time pneumonia and influenza mortality
surveillance system, utilizing daily mortality reports sent by the Office of
Statistics. The goal was to achieve close surveillance of the epidemics and
to respond in an appropriate and timely fashion.
This report utilized mortality case data between January 1, 2008 and
June 27, 2009 (up to 2009 week 26), analyzing 150,551 reports submitted
via the National Death Certificate System. The 4-week moving average
showed the number of pneumonia and influenza mortality cases began to
rise in 2008 week 49, peaked in 2009 week 6, and finally started to decline
in 2009 week 14. The average during non-epidemic period was 217 cases
per week, which rose to 290 cases per week during epidemic period. The
˙Received : July 28, 2009. ˙Accepted : August 19, 2009.
˙Correspondence : Jen-Hsiang Chuang
˙Address : No.6, Linsen S. Rd., Taipei 10050, Taiwan (R.O.C.)
˙e-mail :
728 October 25, 2009
peak was 2009 week 5, which had 373 mortality cases.
Comparison of 2008 pneumonia and influenza mortality case statistics provided by the Office of Statistics, against data collected by the real-time surveillance system, revealed the data from the latter may have overestimated the situation. Analysis of both data sets found a correlation coefficient of 0.85 (p value <0.0001). At present, this surveillance system has been incorporated into the CDC influenza surveillance network. Joining with 3 other systems, they are expected to attain complete surveillance of the evolving influenza epidemic, in order to provide real-time monitoring and early warning.
Keywords: mortality report, pneumonia and influenza, 2009 pandemic influenza A (H1N1)