Pandemic
- Defined by the World Health Organization to include 6 stages of development. At stage 6, a pandemic is is reached.
Definition
A pandemic is the rapid spread of disease to a large population spread across a large region outside of normal local boundaries within a short period of time (1-2 weeks)
Development
Phase I
Phase I is the period before any new infectious subtypes have been detected in animals, a stage that is often missed since new subtypes are occur yearly
Phase II
Phase II begins after the new virus has been shown to infect humans
Phase III
Phase 3 begins when cases of the new virus appear in humans throughout the world for example during H5NI virus, or avian flu, a disease that spread from birds to humans but not from humans to humans. [1]
Phase IV
Phase IV occurs when the virus can easily transmit between humans and results in this results in community-level epidemics
Phase V
Phase V involves disease spread across continents and WHO regions[2] and often is inevitibel until true pandemic is reached.
Phase VI
Phase VI is the definition of a pandemic and requires documentation of the disease in multiple continents or two WHO regions[2]
See Also
References
- ↑ WHO H5N1http://www.who.int/influenza/human_animal_interface/en/
- ↑ 2.0 2.1 WHO Disease Regions http://www.who.int/healthinfo/global_burden_disease/definition_regions/en/