The strain of the H5N6 virus that caused the world's first human death is highly pathogenic to poultry, a health expert has warned.

A 49-year-old man from Nanbu county, Sichuan province, who recently died of pneumonia in a hospital, is the world's first case of human contamination of H5N6, said Ni Daxin, an epidemiologist with the Public Health Emergency Center with the Chinese Center for Disease Control and Prevention.

Ni said the virus has previously been discovered in Taiwan, as well as Germany, Sweden and the United States.

"Yet the previous strains were all of low pathogenic level to poultry, while the virus discovered this time is highly pathogenic to poultry," he said.