An influenza pandemic is a global spread of disease caused by a novel
influenza virus against which the human population has low or no immunity.
The pandemic may not necessarily be caused by avian influenza virus, as seen
from the human swine influenza pandemic in 2009.
2. This document sets out the Hong Kong Special Administrative Region
Government’s preparedness and response plan in case of an influenza pandemic.
It defines the response levels, the corresponding command structures to be set
up, and measures to be taken having regard to the development of the pandemic
situation at each response level. Relevant agencies, companies and
organisations should take note of this plan in devising their contingency plans
and response measures.
3. This plan was updated in 2012 and includes the following key features –
。three response levels, each representing a graded risk of the pandemic
affecting Hong Kong and its health impact on the community;
。examples of possible scenario depicting each response level;
。the standing down mechanism for each response level; and
。fine-tuned response measures based on the latest practical experience.
B. The Government’s Response Systems
4. The Government’s plan includes three response levels – Alert, Serious
and Emergency. These response levels are based on risk assessment of an
influenza pandemic that may affect Hong Kong and its health impact on the
community. Key factors to be considered in the risk assessment include –
。transmissibility of the infection, such as evidence of human-to-human
transmission capable of sustaining community level outbreaks;
。geographical spread of the disease in humans or animals, such as the
global distribution of affected areas, the volume of trade and travel
between the affected areas and Hong Kong;
。clinical severity of the illness, such as serious complications,
hospitalisations and deaths;
。vulnerability of the population, including pre-existing immunity, target
groups with higher attack rates or increased risk of serious disease;
。availability of preventive measures, such as vaccine and antiviral agents;
。recommendations by international health authorities, such as the World
Health Organization (WHO).
5. The assessment of risk is based on the prevailing situation. It should be
noted that information available at the beginning of a pandemic is often limited.
As the pandemic progresses, crucial information to support assessment of the
aforementioned factors, such as the population at increased risk, case fatality
ratio, complication rate, reproductive number and other transmission
characteristics, will gradually come to light. The Government will review the
risk assessment from time to time, having regard to the development of
scientific knowledge and evolving situation, to ensure that the appropriate
response level is activated and corresponding measures are adopted.
Alert Response Level
6. Alert Response Level corresponds to a situation where the risk of a novel
influenza virus causing new and serious health impact in Hong Kong is low.
Generally, it depicts the existence of a novel influenza virus capable of causing
more serious illness than seasonal influenza in neighbouring regions of Hong
Kong, but without imminent risk of causing any human infection in Hong Kong.
Illustrative scenarios are provided in Box 1.
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