Ryan wrote:
According to the The Press Association their was 3,770 cases in the UK. Their was also 26 new deaths reported this week, which would give a fatality rate of 0.7% for the week. Normally the fatality rate is way below 0.1%. Surely this is a bit worrying ?
Not sure I really get your question, anyway the WHO press release issue 22 January states:
World Health Organization - Weekly epidemiological record22 january 2010, 85th year / 22 janvier 2010, 85e année
No. 4, 2010, 85, 21–28[… …]
"Based on currently available data shared with WHO, the prevalence of D222G substitution is <1.8%
(52 detections among >2755 HA sequences).
Of 364 fatal cases analysed to date, viruses from 26 cases (7.1%) had the D222G substitution. The clinical information about potential underlyingmedical conditions in these cases is limited. Surveillance and laboratory analysis efforts to study
this substitution have given priority to specimens from hospitalized and severely ill patients, leading to potential biases in the data. [… …]"
http://www.who.int/wer/2010/wer8504/en/index.htmlThere are at least 3 different ratios or quocients involving the change D225G and fatalities number:
1- From all pH1N1 sequences, which percentage had the change D225G?
2- Among all actual pH1N1 fatal outcomes which percentage had the change D225G?
3- From all detected D225G sequences, how many are associated with a fatal outcome?
All these 3 figures can be calculated from the WHO Weekly epidemiological record data,
although the release focus on the ratios 1 and 2:
Ans # 1 : <1.8% [= 52/2755]
Ans # 2: 7.1% [= 26/364]
Ans # 3: 50 % [= 26/52]
These ratios may or may not rise concern depending on the reader premises.
NOTE-The ratio # 3 was termed by Dr Niman a
CFR (Case Fatality Ratio), a common medical term,
tagged on the research context to the specific
case deffinition as [H3 HA D225G] change detection.
The usual medical use to CFR ratio is the overall
average of fatalities per infected person for a given disease, a less specific use.