A round of tests for H7N9 bird flu on samples taken from Beijing's poultry markets have so far not found any positive samples, local authorities said on Sunday.

The tests have been carried out since December 23 on 22,595 samples from 12,000 poultry farms and households in the city. A total of 6.05 million poultry from 27,000 farms and households have received compulsory immunizations since December 22.

Bird flu, or avian influenza, is a contagious disease of animal origin caused by viruses that normally only infect birds and, less commonly, pigs. It can be fatal to humans.

Several regions, including Shanghai, Beijing, Zhejiang, Jiangsu,Guangdong, Fujian, have reported H7N9 human infections so far this year.

Beijing reported its first human infection case of this year on January 23.

With the forthcoming Chinese Lunar New Year, health experts have called on the public to stay away from live poultry and to maintain good hygiene habits as there is typically a boom in poultry consumption during the festivities. Birds carrying H7N9 are the sources of sporadic infections.