Review - Reviewer's Assessment

1. Short summary / abstract
Earlier this year there was international interest when three children died during the spring influenza epidemics in Hong Kong. (1,2) Following these cases, and the hospital admission of five school children from the same primary school with influenza-like illness, the authorities decided in response to parental concern to bring forward closure for Easter holidays of all primary schools in Hong Kong by 10 days. This was the first school closure since 2003 during the SARS outbreak. The Authorities in Hong Kong have now reported the government ordered investigation that followed these deaths. (3)
The Expert Group that conducted the investigation concluded that influenza was directly related to the death of one of the children, namely the seven-year-old boy who died on March 11 with acute necrotising encephalopathy due to influenza A H1N1. The death of a three-year-old girl on March 1 was likely to be related to an acute cardiac arrhythmia produced by an underlying condition. In this case the influenza A H3N2 virus that was isolated might have acted as one of the possible triggering factors. A third case was a two-year-old boy who died on February 26. The most likely cause of his death was an acute myocarditis of unknown microbial aetiology, as no influenza or other virus could be found in his body despite extensive investigations.(3)

2. What question is the document addressing?
When these cases were first reported in March 2008, ECDC produced a rapid risk assessment highlighting that the cases and fatalities in Hong Kong were tragic, but unexceptional, and that they posed no enhanced risk to Europe though it is important that those travelling to Hong Kong and other equatorial areas appreciate that they may encounter influenza there at any time of the year but especially in what is the spring and early summer in Europe (1,2,5). The Hong Kong Health Protection Centre is a reliable source of information on what current infection hazards can be encountered. Influenza virus can cause severe disease in children and, occasionally can lead to death (4). It is therefore not expected that during seasonal influenza epidemics, cases of children hospitalised or died for severe influenza disease are reported. Efforts should be made protect children during Influenza epidemics including annual vaccination of those aged >6 months with medical conditions predisposing them to more severe influenza disease. These are standard recommendations in most European countries.

3. Type of study

4. Methods valid & appropriate?


5. Results / recommendations reliable?

6. Any major problems and biases?

7. Any other important / relevant studies which confirm or contradict?
1) ECDC Influenza News, 13th March 2008: Recent Deaths in children associated with seasonal influenza in Hong Kong SAR, China. (
2) ECDC threat assessment - 14 March 2008: Influenza situation in Hong Kong, China
3) Report on the investigation of acute febrile deaths in three children during the 2008 seasonal influenza outbreak in HKSAR: Summary and Recommendations. (
4) ECDC Seasonal influenza fact sheet: Seasonal Human Influenza and Vaccination – The Facts (
5) Editorial team. Influenza activity in the Southern Hemisphere: a preliminary look at the winter 2007 season. Euro Surveill. 2007;12(34):pii=3256. Available online:

8. Keywords
Influenza Seasonal Influenza Children

Reviewer's Details:

(Society / Organisation / Advisory Committee):

*** Note: These are the views of a professional expert rather than an official statement from his or her society, organisation or advisory committee.

Twitter FeedTwitter Feed