December 10, 1997
Judging from the investigation of the 4 H5N1 influenza cases, the initial clinical presentation is not different from ordinary influenza cases. However, complications like viral pneumonia, respiratory distress syndrome and renal failure set in rapidly in three cases. Hence, doctors taking care of influenza patients are advised to watch out for symptoms and signs of complications and early hospitalization is advised once the clinical conditions warrant.
There has been concern about the availability of laboratory services to diagnose H5N1 infections. Doctors are advised that they should not wait for the laboratory diagnosis of H5N1 infection before they start appropriate treatment. The laboratory diagnosis would usually take 7 to 10 days because of the time needed for viral culture and sending of specimens to Centres for Disease Control and Prevention in Atlanta, USA. It is prudent to note that treatment for H5N1 infection is essentially the same as for other influenza viruses. Appropriate treatment, including the use of amantadine, should be guided by the clinical assessment and should be started immediately once influenza with complications is clinically diagnosed.
As recommended by the Special Investigation Group on H5N1 Influenza, the surveillance system for influenza has been extended to all the general out-patient clinics under the Department of Health. These centres would undertake the surveillance functions including laboratory investigation of specimens taken from surveillance subjects. This would yield useful information about the incidence and time trend of the H5N1 infection in the local community. At this stage, the laboratory facilities in the Government Virus Unit would be conserved for surveillance activities and for providing support to hospitals.
*This advice will be updated when further information becomes available.