Pharmacist walks past package of anti-influenza virus medicine Tamiflu (File photo)
Japan and Hong Kong say they have each identified cases of the swineinfluenza A-H1N1 virus that are resistant to the anti-viral drugTamiflu. Denmark reported the first such case earlier this week.

Japan'sHealth Ministry said Friday that it discovered the resistance in apatient who had been given Tamiflu after being diagnosed with swineflu. The patient was recovering after taking Relenza, another medicineused to contain the pandemic.

Hong Kong health officials saythey found the Tamiflu-resistant strain in a sample from a 16-year-oldgirl who tested positive for swine flu when she returned from the cityof San Francisco in the U.S. state of California last month.

Thecompany that makes Tamiflu, Swiss drug maker Roche says about half ofone percent of all flu cases are resistant to the drug.

TheWorld Health Organization says more than 77,000 cases of swine flu havebeen confirmed worldwide, including more than 330 deaths.

The WHO recently declared a pandemic - the first in more than 40 years - as the H1N1 swine flu spread worldwide.

Some information for this report was provided by AFP, AP and Reuters.