Two more people have been diagnosed with acute pneumonia due to the H5N1 avian influenza virus, said the Ministry of Public Health on June 12.

A 29-year-old man from Sam Son, central Thanh Hoa province, was infected by the virus after eating meat from an infected duck, said Nguyen Huy Nga, head of the ministry’s Preventive Medicines Department.

The man left the Thanh Hoa hospital on June 6 after recovering from pneumonia-like symptoms, which were later diagnosed as H5N1.

The second case was a 28-year-old woman from Ha Nam province in the Red River Delta. She is in a critical condition at the National Hospital for Tropical Diseases in Hanoi.

Vietnam has now confirmed a total of four cases of human bird flu this year. Two people have recovered, while the other two patients remain in hospital.