CDC: 2 Americans Infected With ‘Dual Mutant’ Flu Strain That Is Immune To Some Drugs

Scientist examines the result of a plaque assay, which is a test that allows scientists to count how many flu virus particles (virions) are in a mixture. (CDC)

A ‘dual mutant’ flu virus has been detected in the US that could make medications less effective, officials are warning.

At least two Americans were infected with a new strain of H1N1, which contains two new major mutations, last flu season, a study found, in a warning sign it may be gaining a foothold.

Across the world, 101 cases were detected out of 15,000 infections analyzed — or 0.67 percent — in five continents, in another sign it is spreading.

Scientists at the CDC are calling the strain a ‘dual mutant’ because it carries two major mutations that make it up to 16-fold more resistant to the main antiviral for flu, oseltamivir, which is prescribed to almost every patient with the infection.

There are no indications at this stage the strain is more infectious or more deadly than other currently circulating viruses.

H1N1 is the strain of flu behind the 2009 flu pandemic, which killed 12,000 people, that spread from pigs to humans. It differs from the H5N1 strain currently sparking alarm in official circles, which is causing an outbreak among US cattle.

Although the strain was found to be more resistant to oseltamivir, further research showed it had no effect on other antivirals for treating flu like baloxavir.

Scientists first detected an H1N1 strain that was more resistant to flu, but had different mutations, in the US during 2007 and 2008.

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