ROME, Nov. 30 (Xinhua) -- The Italian Health Ministry on Monday reported the first case of mutation of the A/H1N1 flu string.

    The ministry said the mutation was identified in a patient with a serious case of pneumonia, who has recovered after treatment with antiviral drugs.

    According to the country's Higher Institute of Health, the variant found in Italy is unrelated to the one blamed for three deaths in Norway and two others in France last week.

    Italian authorities have attributed 91 deaths to the new flu out of an estimated 3 million infections and the government has vaccinated nearly half a million of its citizens.

    Deputy Health Minister Ferruccio Fazio said the single mutation of the A/H1N1 flu virus reported in Italy so far was of no particular concern.

    "This variant is limited to a single patient that we know of ... (it) was kept from spreading," Fazio said.

    Vaccination and antiviral treatments were still effective against the mutation, according to the Health Ministry.

    Fazio said the government would likely extend the vaccination campaign this week to children between six months and 17 years of age, in addition to seniors over 65 suffering from chronic illnesses.

    Though the mutations have stirred fears about potentially dangerous new strains, the World Health Organization said over the weekend that none of them were resistant to the vaccine or antiviral drugs.

Special Report:  World Tackles A/H1N1 Flu