Today pandemic, used as a noun, is often coupled with flu, as in pandemic flu.
According to the World Health Organization (WHO) pandemic flu is a new disease that would affect people around the world, arriving even to the most remote corners of the world. Three criteria determine a pandemic flu and determine the pandemic phase.
- A new influenza subtype emerges to which humans have no immunity.
- Humans are infected and become very sick (or die).
- Is is contagious and spreads from person-to-person efficiently.
Pandemic as a noun: Health officials fear that a new type of bird flu could cause a pandemic.
Pandemic as adjective: Currently the H5N1 virus lacks one property to make it the next pandemic flu candidate, it is not very contagious.
Sources: World Health Organization (WHO) Avian Influenza Frequently Asked Questions (FAQs), http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/index.html#areall
