Health authorities in south Guangdong Province have identified the type of the virus that led to the death of a bus driver, but the cause of the bird flu remains unclear, a local disease control center confirmed Monday.

The receptor of the virus, a highly pathogenic H5N1, is poultry, according to a statement released by the Shenzhen Disease Control Center.

Though it is highly pathogenic to human beings, the virus can not spread among people, the center said in the statement, adding that there is no need for Shenzhen citizens to panic.

Genetic analysis also indicated that the virus was spread directly from poultry to human, according to the statement.

A 39-year-old man surnamed Chen in Bao'an district of Shenzhen was hospitalized for fever on December 21 and tested positive for the H5N1 avian influenza virus. Chen died of multiple organ failure Saturday afternoon.

Health authorities are trying to figure out where Chen acquired the virus.

The Guangdong Department of Agriculture announced Saturday that no epidemic of bird flu among poultry had been reported in the province.