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The Department of Health's Public Health Laboratory Services Branch (PHLSB) today (January 31) detected a strain of Human Swine Influenza (HSI) virus which is resistant to oseltamivir (Tamiflu).
A department spokesman said the virus was identified during PHLSB's routine sensitivity tests of the HSI virus to oseltamivir and zanamivir.
"This is the seventh case of Tamiflu resistance to HSI 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 January 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 HSI virus. He has been discharged and is now in stable condition.
Test results today showed that the virus isolated from the patient's nasopharyngeal aspirate on January 19 was resistant to Tamiflu but sensitive to Relenza.
The boy had been prescribed with Tamiflu during hospitalisation 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 HSI from the patient.
The case will be reported to the World Health Organization (WHO).
The spokesman said that Hong Kong has an intensive surveillance system for antiviral resistant influenza viruses. The PHLSB conducts routine sensitivity tests on specimens taken from confirmed HSI patients.
"So far more than 6,500 HSI samples have been tested for antiviral sensitivity in Hong Kong," he said.
"We will closely liaise with the WHO and overseas health authorities to monitor the global development of antiviral-resistant HSI virus."
Ends/Monday, January 31, 2011
Issued at HKT 17:44
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