Role of Emerging Infectious Diseases

Krupa Patel Midterm Assignment Microbiologist and Nobel Prize winner Joshua Lederberg first coined the phrase “emerging infectious diseases” to describe infections that were newly appearing in a population or having existed but rapidly increasing in incidence or geographic range.1 Emerging diseases can be attributed to either true emergence (i.e. a newly appearing pathogen that has not been present), increased recognition (i.e. a pathogen that was present in a population but has only recently been recognized due to improved diagnostic tests\capabilities), and increased incidence of previously recognized diseases mainly due to increased globalization, travel, urbanization, and susceptibility of host population4. When there is a disturbance to the natural environment, for example logging and urbanization, pathogens and reservoirs are disturbed and displaced leading to emergence in the human population and increased infection rates. Many emerging viral diseases are caused by some variety of RNA viruses, which compared to DNA viruses, have a higher susceptibility to mutation. For example, influenza is caused by RNA viruses of the family Orthomyxoviridae and known for strain mutation year after year, thus the need for reformulation of the vaccine for what will hopefully be the most common strains to infect people that particular season. Though the factors responsible for disease emergence can often be recognized, intervention and defense against these diseases has proven to be difficult. The definition of emerging disease has evolved rapidly over the last few decades. In 1992, the Institute of Medicine released a statement defining “emerging infectious diseases [as] diseases of infectious origin whose incidence in humans has increased within the past two decades or threatens to increase in the near future.2 The IOM definition was too restrictive, not accounting properly for animal and zoonotic diseases and their impact on the public. Even though specific

References: 2. Institute of Medicine. Emerging Infections: Microbial Threats to Health in the United States. Washington, D.C.: National Academy Press, 1992. 5. “Antimicrobial resistance.” medical-dictionary.thefreedictionary.com, 2012. Web. 20 Nov 2012.