# 8318
A follow up to my earlier report on China’s Ministry of Agriculture’s H7N9 cases counts and fatalities (see China’s MOA: H7N9 Fatalities Higher Than Previously Announced) comes courtesy of sharp-eyed Lisa Schnirring at CIDRAP NEWS who spotted what I read right past this morning in the WHO’s Recommended Composition Of 2014-15 Northern Hemisphere Flu Vaccine report.
Embedded halfway down the second page is a brief synopsis with an even higher H7N9 fatality count (112 vs. 109) than we saw announced earlier today from the China’s MOA, although with an increase in the number of overall cases (355 vs. 347) the resultant CFR (Case Fatality Ratio) is only marginally higher.
Zoonotic influenza infections caused by A(H5N1), A(H7N9), A(H9N2) and A(H10N8) viruses
From 24 September 2013 to 17 February 2014, 15 confirmed human cases of A(H5N1), 9 of which were fatal, were reported from Cambodia, Canada, China, Indonesia and Viet Nam. Highly pathogenic avian influenza A(H5N1) is present in poultry in each of these countries except Canada. Since December 2003, a total of 652 cases with 387 deaths have been confirmed in 16 countries. To date there has been no evidence of sustained human-to-human transmission.During this period 220 additional human cases of avian influenza A(H7N9) virus infection have been reported. All cases were in China with the exception of a single case detected in Malaysia in an individual travelling from Guangdong Province, China. Since February 2013, a total of 355 cases with 112 deaths have been reported3
Two cases of A(H9N2) were reported in this period, one each in China, and China Hong Kong Special Administrative Region. The associated disease in both cases was mild with both viruses belonging to the A/chicken/Hong Kong/Y280/97 genetic lineage.
Three cases of A(H10N8) with two deaths were reported from Jiangxi Province, China during this period.
While these numbers are not an exact match (likely due to different report cutoff dates), this is a very useful confirmation of the Chinese MOA report from earlier today, which indicated a mortality rate of over 31% among known cases.
There are, almost certainly, some unknown number of mild or asymptomatic cases not being counted. So this doesn’t tell us the absolute CFR (case fatality ratio) of this infection, only the current mortality rate among patients ill enough to be hospitalized.
Given that there are a number of already counted cases that are currently hospitalized, but whose outcome is not yet known, it is also possible this ratio could go higher.
What we don’t seem to have at this point is a sense of whether this mortality rate has remained more-or-less constant since the outbreak began a year ago, or if it has increased during this second wave.
For now, despite the high mortality rate of this virus, the good news is that it hasn’t shown the ability to transmit efficiently between humans. But, like all influenza viruses, what we can say about it today may not hold true next week, or next year.
