Emerging Infections

An emerging infectious disease can be one that has recently been recognised. Or it can be a disease where cases have increased (or look as though they might be on the increase) over the last 20 years, in a specific place or among a specific population.

Over the past 25 years, more than 30 new, or newly-recognised, infections have been identified around the world. The pattern of known infections also changes constantly, as the areas where disease is constantly present expand beyond traditional limits.

Emerging infections may be:

• A new infection resulting from changes in existing micro-organisms
• A recognised infections spreading to new areas or populations
• A previously unrecognised infection appearing in areas where the habitat is changing (e.g. deforestation)
• The discovery that a known disease is caused by an infection, for example, finding out that something infectious can cause a long-term (chronic) disease
• An old infection re-emerging because it has become resistant to treatment, or as a result of a breakdown in public health initiatives