Hong Kong"e;s Department of Health"e;s Public Health Laboratory Services Branch (PHLSB) Monday announced that a strain of A/H1N1 influenza virus which is resistant to anti-virus drug oseltamivir (Tamiflu) was detected.

A department spokesman Monday said the virus was identified during PHLSB"e;s routine sensitivity tests of the A/H1N1 virus to oseltamivir and zanamivir.

"This is the seventh case of Tamiflu resistance to A/H1N1 flu virus detected in Hong Kong. Tests showed that this strain is sensitive to zanamivir (Relenza)," he said.

The virus was isolated from the specimen taken from a two-year-old boy who developed flu-like symptoms beginning Jan. 10. He was admitted to Tuen Mun Hospital on the same day and his nasopharyngeal aspirate specimen taken on the day of admission tested positive for A/H1N1 virus. He has been discharged and is now in stable condition.

Test results Monday showed that the virus isolated from the patient"e;s nasopharyngeal aspirate on Jan. 19 was resistant to Tamiflu but sensitive to Relenza.

The boy had been prescribed with Tamiflu during hospitalization and it is likely that Tamiflu resistance emerged during the course of drug treatment.

The spokesman said there was no evidence of further transmission of Tamiflu-resistant A/H1N1 from the patient.

The case will be reported to the World Health Organization.