Influenza is a highly infectious viral disease. It is caused by various types of influenza viral strains. New subtype variants of the virus appear from time to time and at irregular intervals. This is responsible for seasonal outbreaks. In Hong Kong, the disease is more common in periods from January to March and from July to August.
At the same time, local and overseas health experts have sounded a grave concern with the potential occurrence of an Influenza Pandemic. (A pandemic exists when a new virus has caused illness at epidemic levels involving the population of more than one country.) The threat is becoming more apparent in recent times with the occurrence of cases of both poultry and human avian influenza. 116 human cases were affected in 2004/05 with 60 deaths. These cases occurred in Vietnam, Thailand, Cambodia and Indonesia.
The periodic and seasonal influenza outbreaks arise as a result of minor genetic changes in the influenza viruses. For healthy individuals, this ‘ordinary influenza’ or human influenza (e.g. H3N2 and H1N1) is usually self-limiting with recovery in 2 to 7 days. However, Influenza Pandemic emerges as a result of major genetic changes in the influenza viruses against which the population have very little or no immunity. When people are concurrently infected with human and avian influenza virus strains (e.g. H5N1 and H9N2), they may serve as the ‘mixing vessel’ for the emergence of a novel subtype of virus having sufficient human influenza genes to facilitate transmission from person to person and this is one possible way leading to influenza pandemic. At time of the pandemic, more than 15% of the world population may be affected and the mortality rate is estimated to be about 50%.
The Department of Health has put in place a strategic plan in readiness for the occurrence of the pandemic. An alert system has been devised to initiate actions at different stages of the pandemic. Currently, the system is at the Alert Response level (or Yellow Alert) signifying the identification of human cases outside of Hong Kong. To enhance the preparedness of the local community, it recommends a series of action to build up general awareness and to provide guidelines for everybody for personal hygiene, as well as a range of preventive measures.
In light of the above, the Committee on Health Promotion and Protection (the Committee) has reviewed the current situation of Influenza and stepped up actions to prepare for the Influenza Outbreak and Pandemic. The Committee draws reference to the action plans of the Government to supplement and reinforce their action on campus. It encourages the University community to step up personal and environmental hygiene action and introduces preventive and other specific measures as follows:
- The Committee will continuously monitor the development of influenza outbreaks and coordinate action through Colleges/Departments/Units; obtain expert advice from Government and microbiologists; acquire and allocate resources; issue guidelines; and advise University activities such as examinations and classes at times of major outbreak/pandemic.
- Public information and awareness enhancement through various channels; and face-to-face forums with all staff and student groups.
- Medical surveillance: the Committee and the University Health Service (UHS) to keep track of government action; patient records; infected cases and contact tracing.
- Public preparedness: use of mask and its supply; hand washing skills; droplet precautions; thermometer use; issuing of guidelines; training; and communication.
- Prevention: vaccination programme; antiviral drug stockpiling; and environmental hygiene.
- Treatment service at UHS: UHS referral protocol; triaging system; UHS internal service contingency plan; stockpiling of treatment medication including antiviral drugs and PPE; laboratory readiness; deployment of health care staffing; and liaison with hospitals and Department of Health.
Influenza vaccination is one of the effective means in preventing ‘ordinary influenza’ and its complications. The Hong Kong Scientific Committee on Vaccine Preventable Diseases recommended 8 target groups for influenza vaccination:
- Elderly persons living in residential care homes
- Long-stay residents of institutions for the disabled
- Elderly persons aged 65 years or above
- Persons with chronic illnesses (those with chronic cardiovascular, lung, metabolic or renal disease)
- Health care workers
- Poultry workers
- Children aged 6 to 23 months
- Pregnant women in the second or third trimester
The seasonal influenza vaccine is ineffective against the new virus that can trigger off the pandemic. When an Influenza Pandemic occurs, a new vaccine will need to be developed to match the pandemic virus strain. The new vaccine for pandemic strains needs at least a few months to prepare and the limited production capacity is unlikely to meet the global demand.
Antiviral drugs (Oseltamivir [Tamiflu], and Zanamivir [Relenza]) can also be used for treatment and prophylaxis for ‘ordinary influenza’. The drugs need to be prescribed by doctors. During an Influenza Pandemic period, the drugs may be used for treating the patients.
Members of the University community, staff and students are advised to refer regularly to the Committee on Health Promotion and Protection website. The website contains useful information on the updated position in regard to outbreaks or the pandemic, and to guidelines of personal and University action at different stages of development of the disease.
UHS has introduced Influenza vaccination programme since September 2005. Staff and students are invited to come to UHS or consult their own doctor for the vaccination. Public announcement including posters are made regularly to invite all who wish to receive the vaccine, especially those belonging to the high risk group to come to UHS. The vaccination programme will continue for as long as stock is available.
A series of talks and briefing sessions are being organised for various groups of staff and student audience. The presentation will brief participants of the latest information regarding the influenza, the potential Influenza Pandemic, the action taken by the Government and the University as well as individual responsibilities. For enquiries, please contact UHS at Tel. 3943 6436.
Committee on Health Promotion and Protection
October 24, 2005