The death toll from the H7N9 bird flu outbreak in China has risen to 43, national health authorities said in their latest monthly update on the disease.

A total of 132 human infections of the virus had been confirmed on the Chinese mainland by the end of June, the National Health and Family Planning Commission said late Wednesday.

The figures represent one more case and four deaths during the month.

The Shanghai government reported last month that a 56-year-old man, the husband of an earlier victim, had died bringing the death toll up to 40.

National health authorities did not provide details on the three remaining fatalities, but said that 85 H7N9 patients had been discharged from hospitals after treatment.

That would leave just four people still in hospital following the outbreak.

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

Experts fear the possibility of the virus mutating into a form easily transmissible between humans, with the potential to trigger a pandemic.

But the World Health Organization has said there is no evidence of human-to-human transmission.