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Polio (poliomyelitis)

Polio (poliomyelitis)

Poliomyelitis (polio) is a paralytic disease caused by poliovirus, a highly infectious virus. Poliovirus is transmitted primarily from person-to-person via the fecal-oral route. At its peak in the United States, an estimated 21,000 cases of poliomyelitis were recorded in 1952. Polio vaccine was introduced in 1955, and the disease was declared eradicated from the Western Hemisphere in 1991, from the Western Pacific in 1997, and from Europe in 1998. The illness still occurs in some developing countries such as Afghanistan, India, Nigeria, and Pakistan and can be imported into countries where the disease has been eradicated, causing infections in susceptible or unvaccinated persons.


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Polio in King County

Purpose of surveillance:

  • To identify cases of imported poliomyelitis
  • To identify cases and susceptible contacts of cases for immunization and to institute infection control measures
  • To differentiate naturally-occurring and vaccine-associated polio viruses
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