10 December 2003
Dear Doctor,
The Public Health Laboratory Centre of the Department of Health confirmed a human case of influenza A (H9N2) infection yesterday. The patient was a 5-year-old boy with onset of illness in November 2003. He had good past health and no recent travel outside Hong Kong. He was admitted with a two-day history of fever, cough, and runny nose. His nasopharyngeal aspirate was tested positive for influenza A (H9N2) on 9 December. He made a complete recovery and was discharged.
Influenza A (H9N2) virus is commonly found in poultry and the avian population. In Hong Kong, human infection was first reported in 1999. Two girls, aged one and four, who suffered from influenza-like-illness were confirmed to have influenza A (H9N2) virus. Both girls recovered uneventfully. Subsequent serological studies conducted in Hong Kong suggested that human influenza A (H9N2) infection was uncommon in this local community. For more details, please make reference to the article "An Update on the Influenza A (H9N2) in the Hong Kong Special Administrative Region" of the Public Health and Epidemiology Bulletin at http://www.info.gov.hk/info/flu/eng/bulletin.htm .
Based on the experience from the three human cases, the initial clinical presentation of influenza A(H9N2) infection is similar to that of other influenza viruses, typically with fever and cough. The appropriate management consists of adequate rest, fluid replacement and antipyretic as necessary. Aspirin should be avoided because of possible occurrence of Reye's Syndrome. If there are signs of complications such as pneumonia, the patient should be hospitalized. There are commericially available rapid screening tests for detection of influenza A antigen. Virus isolation by culture is required for confirmation of H9N2. A four-fold or greater rise in antibody titre from the acute phase to the convalescent phase serum samples is indicative of recent infection.
On a territory basis, the number of hospital admissions for pneumonia and influenza recently has remained stable. Concerning the sentinel surveillance on influenza-like-illness, the consultation rates among general practitioners and general out-patient clinics did not show abnormal rise. For more details and statistics, please visit our website at http://www.chp.gov.hk/en/guideline1_year/29/134/441/304.html .
Your assistance is solicited to advise patients on the prevention of avian influenza. This includes avoidance of contact with live poultry / birds (especially in children), wash hands thoroughly after contact with live poultry / birds, observance of good personal hygiene, maintaining good ventilation, no smoking, and having a balanced diet, regular exercise and adequate rest to maintain body immunity.
The DH stands ready to offer advice and assistance to medical professionals who detect unusual or unexplained pattern of illnesses. Please notify such incidents to the respective Regional Office of the DH. The contact numbers are as follows:
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Regional Office
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Fax No.
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Tel. No.
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Hong Kong
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2572 7582
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2961 8729
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Kowloon
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2375 8451
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2199 9149
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New Territories East
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2699 7691
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2158 5107
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New Territories West
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2439 9622
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2615 8571
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