COPENHAGEN, Denmark – The H5N2 avian influenza virus that is killing poultry flocks in the United States and abroad isn’t known to infect humans. However, sporadic infections in humans with subtypes of the H5 virus have been documented.

That’s why the World Health Organization’ Regional Office for Europe released an overview of avian influenza viruses known to cause illness in humans.

According to WHO, three subtypes of avian influenza A (H5, H7 and H9) are known to infect people. Since 2013, several new LPAI viruses (A(H7N9), A(H6N1), A(H10N8)) have infected humans and sometimes led to severe or lethal cases, WHO noted. HPAI A(H5N1) has been detected in humans since 2003 and regularly causes new fatalities. One novel HPAI A(H5N6) virus has been reported to cause human disease for the first time in 2014.

WHO developed the overview for public health professionals. The report, which includes data from countries from all six WHO regions, provides a comprehensive picture of avian influenza strains and their spread across the world.