The DORSCON Alert codes describe the risk of acquiring an infectious disease. It provides a guide for planning and execution in the event of an influenza pandemic. However, if the progression of the disease is very fast, it may not be operationally feasible to have a clear, sequentially graduated response.
Alert GREEN Level 0 (WHO Phase 1).
· Low Threat with no novel influenza virus outbreaks anywhere in the world.
Alert GREEN Level 1 (WHO Phase 2 - 3)
· Present of global concern about the possible emergence of a novel virus with isolated animal to human spread from closed prolonged contact. The disease is basically limited to animals and the threat of human-to-human infection remains low.
Alert YELLOW (WHO Phase 4).
· There are inefficient human-to-human transmissions of influenza caused by a novel virus requiring close and sustained contact to an index case. Further spread can be prevented through public health measures to isolate cases and quarantine contacts. The risk of import into Singapore is elevated. Isolated imported cases may occur but there is no sustained transmission.
Alert ORANGE (WHO Phase 5).
· Globally and/or locally, larger cluster(s) but human-to-human spread is still localized suggesting that virus is becoming increasingly better adapted to humans but may not yet be fully transmissible, requiring close contact with an index case (substantial pandemic risk). In most instances, there will be dead end transmissions. But in some instances, a cluster of cases may develop from an index case.
Alert RED (WHO Phase 6).
· A pandemic is underway. The virus is fully transmissible between humans. Import into Singapore is inevitable. Sources of infection are undefined and there is a high risk of acquiring the disease from the community once it spreads to Singapore.
Alert BLACK (WHO Phase 6).
· There are high rates of severe disease and deaths. The healthcare and other social support systems are overwhelmed by the pandemic. Economic activities are severely disrupted.
Ref: http://www.mhchealthcare.net/definition-of-dorscon-flu-alert-codes/
