Vaccines, Immunology and Clinical Trials

Emerging and Infectious Diseases

Emerging infectious diseases are infections that have recently appeared within a population or those whose incidence or geographic range is rapidly increasing or threatens to increase soon. Emerging infections can be caused by:

• Previously undetected or unknown infectious agents.
• Known agents that have spread to new geographic locations or new populations.
• Previously known agents whose role in specific diseases has previously gone unrecognized.
• Re-emergence of agents whose incidence of disease had significantly declined in the past, but whose incidence of the disease has reappeared. This class of diseases is known as re-emerging infectious diseases.