A Chinese woman infected with the deadly H7N9 bird flu virus died of multiple organ failure, a Beijing hospital said, bringing the total fatalities from the disease to 45.

The 61-year-old tested positive for the virus on July 20 after she fell ill in Hebei province in northern China.

She was taken to Beijing's Chaoyang Hospital for treatment and died on Sunday, the hospital said in a statement.

A total of 134 cases have now been confirmed on the Chinese mainland, including one in Guangdong, the first in the southern province, which was reported on Saturday.

State news agency Xinhua said then that 44 people had died of the disease.

The virus was first reported in late March, with most cases confined to eastern China, and only one reported outside the mainland, in Taiwan.

Scientists reported last week the first likely case of direct person-to-person transmission of the H7N9.

But they said there was no cause for panic as the virus's transmissibility remained "limited and non-sustainable".

Cases of H7N9 have dropped significantly in recent months.