Two deaths in France from mutated H1N1

Two patients who were infected by a swine flu mutation that was also recently detected in Norway have died in France, health officials say.

"This mutation could increase the ability of the virus to affect the respiratory tracts and, in particular, the lung tissue," a statement from the French government's Health Surveillance Institute (InVS) said on Friday.

"For one of these patients, this mutation was accompanied by another mutation known to confer resistance to oseltamivir," it added, referring to the main drug being used to treat swine flu, under the brand name Tamiflu.

The case was the first drug-resistant strain found in France among the 1,200 strains experts have analysed here, the InVS said, adding that "the effectiveness of vaccines currently available is not being questioned".

The two patients were not related and had been hospitalised in two different cities in France, it said.

The death toll in mainland France now stood at 76, the InVS statement said.

The World Health Organisation said on Thursday it was investigating reports of mutations in the swine flu virus, after half a dozen countries recorded cases in which the virus was transforming.