Emerging and re-emerging infections.

Emerging infectious diseases are diseases of infectious origin whose incidence in humans has increased within the past decades or threatens to increase in the near future. The reappearance of a previously known infection after a period of disappearance or decline in incidence is known as re-emergence. Many factors are known to contribute to the emergence or re-emergence of a disease. For example research indicates that newly emergent infections may result from changes in or the evolution of existing organisms the spread of known diseases to new geographic areas or human populations or the appearance of previously unrecognized infections in persons living or working in areas undergoing ecologic changes which increases individual exposure to insects animals and environmental sources which may harbor new or unusual infectious agents. An infectious disease may re-emerge due to a range of reasons including the development of antimicrobial resistance and/or insecticide resistance among vectors and the collapse of public health systems. Pathology and emerging infections examples of emerging and re-emerging infections the contributions of pathology to emerging infections autopsy and emerging infections global microbial threats emerging and re-emerging infections in India tuberculosis nosocomial infections the current status of infectious disease pathology and combatting infectious disease threats are discussed.