The Chinese National Health and Family Planning Commission announced the confirmation of a human case of avian influenza A(H5N6) Saturday affecting a 37-year-old woman in Yunnan province.

China /CIA
China /CIA

The patient, presented with fever and cough with sputum since July 6, was admitted to a local hospital on July 9 and died on July 10.

This is the fourth human case of this strain of bird flu with two cases reported in 2014 HERE and HERE, and one case reported at the beginning of 2015. Three of the four cases have resulted in death.

In September, the Food and Agricultural Organization of the United Nations (FAO) released a report concerning this avian flu virus calling it “worrisome” as a threat to birds.

Chinese authorities first reported the influenza A(H5N6) virus in poultry in April 2014. Since then, the Lao People’s Democratic Republic and Viet Nam have also detected the H5N6 virus in poultry.

Related: H5 Avian influenza rising in China

“Influenza viruses are constantly mixing and recombining to form new threats,” said FAO’s Chief Veterinary Officer, Juan Lubroth. “However, H5N6 is particularly worrisome, since it has been detected in several places so far from one another, and because it is so highly pathogenic, meaning infected poultry quickly become sick and, within 72 hours, death rates are very high.”