Monday, November 30, 2009

ECDC Weekend Update

 

 

# 4100

 

On Monday morning we get an update from the ECDC on H1N1 pandemic activity in Europe over the previous 72 hours (Friday/Saturday/Sunday).

 

With this report we also get an update on the mutations seen in the HA1 gene of the H1N1 virus.

 

Main developments in past 72 hours

  • Influenza activity is high in 27 EU countries and 13 countries report a rising trend
  • More  mutations  have  been  reported  by  EU  countries,  with  a  few  in  the  haemagglutinin  gene  at location 222
  • A total of 858 fatal cases in Europe and EFTA countries and 7 710 in the rest of the world have been reported up to date.

 

 

Mutations in the haemagglutinin HA1 gene D222G

Following initial reports from Norway, WHO has noted that a spontaneous mutation in the haemagglutinin gene D222G has been observed in at least seven countries world-wide (1). These spontaneous mutations have been detected retrospectively following genetic sequencing. They were first detected in April and were seen in Mexico and the USA and so are not a recent phenomenon (1,2).

Finnish and French virologists reported another three cases last week (3).  As in a number of the cases the viruses were reported from two patients with very severe illness who died. WHO and ECDC are currently assessing the public health significance of this mutation (1,2). It is unclear whether the mutation is especially pathogenic or whether it is somehow selected for in very ill patients. 


However there is no evidence that the virus is transmitting, none of the patients are reported to be connected to each other and the mutation is not spreading in Europe. As further sequencing is undertaken reports of its detection in other European countries can be expected.

 

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