Avian influenza (H7N9) update

13 Feb 2014

The DoH has provided the AMA with a surveillance update on the H7N9 outbreak in southern China, current as at 6 February 2014. The outbreak continues unabated, mainly affecting elderly people in contact with domestic poultry. The WHO has reported 298 human infections including 63 deaths since February 2013. The disease is characterised by rapidly progressing severe pneumonia and/or Acute Respiratory Distress Syndrome (ARDS), although mild cases have been reported. As of 28 January 2014, the case fatality rate of all confirmed cases is 22 percent, but many cases are still hospitalised. No adaptation to efficient person-to-person transmission has been observed so far.

Since 1 October 2013 there have been 165 sporadic cases reported in a ‘second wave’ of human H7N9 infections. The first wave occurred in the first half of 2013 with a total of 136 cases. Accumulation of almost 300 cases in less than a year appears to be unprecedented for human cases of avian flu. For comparison, data from the WHO shows that the most active calendar year for the H5N1 strain in 2006 saw 115 cases.

Distribution of cumulative number of human cases of avian influenza A(H7N9), by province, China, to 13 February 2014

Distribution of cumulative number of human cases of avian influenza A(H7N9), by province, China, to 13 February 2014

Note: Chinese provinces with reported cases are shaded in blue. This figure includes cases and deaths confirmed by local authorities; some of these cases have not yet been acknowledged by WHO.

Chart by University of Minnesota

With Chinese New Year recently being celebrated, it is anticipated that during February there will be an increase in the number of incoming passengers to Australia from China. Given the steady increase of confirmed H7N9 cases since 1 January 2014, there is a possibility of cases of H7N9 presenting in Australia.

Surveillance Update 13 February 2014

More information is also available on the DoH website.

** Updated with new map and PDF download 18 February 2014 **