National influenza surveillance in Vietnam, 2006-2007.
Nguyen HT., Dharan NJ., Le MTQ., Nguyen NB., Nguyen CT., Hoang DV., Tran HN., Bui CT., Dang DT., Pham DN., Nguyen HT., Phan TV., Dennis DT., Uyeki TM., Mott J., Nguyen YT., Vietnam National Influenza Surveillance and Evaluation Team None.
In 2006, national influenza surveillance was implemented in Vietnam. Epidemiologic and demographic data and a throat swab for influenza testing were collected from a subset of outpatients with influenza-like illness (ILI). During January 1, 2006 through December 31, 2007, of 184,521 ILI cases identified at surveillance sites, 11,082 were tested and 2112 (19%) were positive for influenza by reverse transcription polymerase chain reaction. Influenza viruses were detected year-round, and similar peaks in influenza activity were observed in all surveillance regions, coinciding with cooler and rainy periods. Studies are needed to ascertain the disease burden and impact of influenza in Vietnam.