Thursday, March 14, 2013

WHO: March H5N1 Update

 

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Credit WHO

 

# 7006

 


The World Health Organization now provides a monthly summary of H5N1 activity, generally around the mid-point of each month on their Influenza at the Human-Animal Interface (HAI) page.


The latest report, dated March 12th, provides an updated table (see Cumulative number of confirmed human cases of avian influenza A(H5N1) reported to WHO, and narrative (see Human-Animal Interface risk assessment summary), from which I’ve provided excerpts below.

 

Since the first of the year, there have been 12 human infections from the H5N1 virus reported from 3 different countries (China, Cambodia, & Egypt), with 11 of those being fatal.  

 

Two new cases (both previously reported in Cambodia) are included in this latest report.

 

 

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Influenza at the human-animal interface


Summary and assessment as of 12 March 2013

Human infection with avian influenza A(H5N1) viruses and associated animal health events


From 2003 through 12 March 2013, 622 laboratory-confirmed human cases with avian influenza A(H5N1) virus infection have been officially reported to WHO from 15 countries, of which 371 died.


Since the last update on 15 February 2013, 2 new fatal laboratory-confirmed human cases with influenza A(H5N1) virus infection were reported to WHO from Cambodia. China reported 2 deaths in the human cases previously reported (http://www.who.int/influenza/human_animal_interface/HAI_Risk_Assessment/en/index.html).


Since the beginning of 2013, Cambodia reported nine human cases with influenza A(H5N1) virus infection including eight fatal cases. These cases come from five provinces all located in southern Cambodia. These cases do not seem to be linked epidemiologically, and most had contact with sick poultry in their villages. The clade 1.1 viruses that have been isolated from cases are very similar to those isolated from poultry in the region. Investigations around these cases did not detect additional cases. This evidence suggests sporadic infections from exposure to infected poultry or contaminated environments, rather than human-to-human transmission. It has been suggested that the A(H5N1) virus is circulating endemically in poultry in Cambodia1 , as such, additional sporadic human cases might be expected.

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Public health risk assessment of avian influenza A(H5N1) viruses: Any time influenza viruses are circulating in poultry, sporadic infections or small clusters of human cases are possible especially in people exposed to infected poultry kept in households or contaminated environments. However, currently, this A(H5N1) virus does not appear to transmit easily among people and therefore the risk of community level spread of this virus remains low. Therefore, the public health risk associated with this virus remains unchanged.


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