China has reported six new cases of deadly H5N6 avian flu – three of them in Guangdong – but the virus has not mutated to a human-to-human transmission, according to local officials.

H5N6 attacked lung tissue rapidly and was likely to be deadlier than the H7N9 strain detected in previous years, Guangzhou Daily reported yesterday.

All three of the H5N6 patients in Guangdong had contact with live poultry or had been to live poultry markets, the report said.

A 40-year-old woman from Zhaoqing (肇慶) is the latest case.

She was pregnant when she was diagnosed with the virus on January 1. Doctors performed a caesarean section and the patient remained in severe condition in a hospital intensive care unit.

A 26-year-old woman from Shenzhen’s Baoan district was diagnosed with the virus on December 29, three days after her symptoms emerged. She had bought a live duck from a local market and died on December 30.

The first H5N6 case in Guangdong, a 58-year-old man from Panyu district in Guangzhou, was recorded on December 15.

He tested positive for the virus after buying a chicken at a wet market but recovered after nearly a month of treatment.

No person in close contact with any of the patients had tested positive for H5N6, the report said.

One of the remaining three H5N6 cases was reported in Sichuan (四川) and the other two in Yunnan (雲南) province.

According to He Jianfeng, spokesman for the Guangdong Provincial Centre for Disease Control and Prevention, the virus had not mutated to be directly transmittable between people. He urged the public to avoid buying freshly slaughtered poultry.

However, many wet markets in Guangzhou are still offering freshly slaughtered poultry under the table despite campaigns in the last two years to curb the live trade.

No other H5N6 cases have been reported in the world this year.