Poliomyelitis is a viral disease that destroys nerve cells and, in the most severe cases, causes acute flaccid paralysis. The virus replicates in the motor neurons of the anterior horn and brain stem resulting in cell destruction causing the typical manifestations of polio and sometimes resulting in death. Polio incidence fell rapidly following the introduction of polio vaccines in the 1950s (IPV) and early 1960s (OPV). The world is almost polio free now, with the last case in the United States caused by wild poliovirus occurring in 1979. The Americas were declared polio free in 1994, and very few countries in the world report polio cases now.
Poliomyelitis reporting serves to: 1) detect importation of wild poliovirus into the U.S. and 2) detect the presence of vaccine-derived poliovirus in the U.S. Because of the severity of poliomyelitis disease (it is a paralytic disease), timely reporting of suspected cases is extremely important, especially among unvaccinated groups. Disease reporting by clinicians is often delayed, because it is only after other differential diagnoses are ruled out that the diagnosis of poliomyelitis is considered. Efforts should be made to promote physicians’ awareness of the importance of prompt reporting of suspected cases to the state and local health department and the Centers for Disease Control and Prevention (CDC), and the need to obtain stool and serum specimens early in the disease course.
Poliovirus is mainly passed through person-to-person contact. The virus enters the environment through feces of infected people, then is passed to others, especially in situations with poor hygiene.