HONG KONG Oct 12 Vietnam has detected three
cases of swine flu that were resistant to the antiviral drug
Tamiflu, but an expert said there was no evidence the mutant
strains had infected other people.
The three were admitted to the Hospital for Tropical
Diseases in Ho Chi Minh city in late August and September and
have all recovered, said Rogier van Doorn, a clinical
microbiologist and doctor at the hospital.
"The viruses that were isolated when they were admitted
were still sensitive (to the drug), but during treatment with
oseltamivir, resistance built up," said van Doorn, referring to
the generic form of Tamiflu.
"So it was not transmission of resistant viruses, but we
observed that it developed during treatment of these three
patients ... we have no evidence to show that (there was
further transmission of resistant viruses)," he told Reuters.
Tamiflu is made by Roche ROG.VX and Gilead Sciences Inc
(GILD.O) and is one of two drugs shown to work well against
H1N1 swine flu.
The three drug-resistant cases were among more than 600
H1N1 patients who were treated at the hospital.
Two of the patients had very mild disease and the third, a
3-year-old child, was admitted to intensive care but made a
full recovery within 10 days.
Tamiflu-resistant swine flu cases have been reported in
Japan, Hong Kong, Denmark and the United States.
Flu viruses are mutation-prone and experts are not
surprised that they would evolve resistance, just as bacteria
develop resistance to antibiotics.
However, experts fear such resistance may spread and
complicate efforts to treat victims with the approach of what
is likely to be a second wave of swine flu infections as the
Northern Hemisphere enters the winter season.
(Reporting by Tan Ee Lyn; Editing by Alex Richardson)