Pathogenesis (development of disease)
Poliovirus (genus: enterovirus; family: Picornaviridae) is ingested orally (“by mouth“). It then replicates in the cells of the gastrointestinal (GI) tract and lymph nodes. Via the bloodstream, it finally reaches the central nervous system (CNS), where it attacks motor nerve cells, which it destroys by dissolving the cell. Notice. Three serotypes are known: Type I (Brunhilde), which is considered to cause paresis (paralysis) most severely and tends to spread epidemically, alongside Type II (Lansing) and Type III (Leon). There is no cross-immunity between the three pathogen types. That is, infection with one of the three types does not protect against further infection with either of the other two types.
Etiology (causes)
Biographic causes
- Occupations
- Medical personnel who may have close contact with ill persons
- Personnel in laboratories with poliomyelitis risk diagnostics.
Causes related to the disease
- Trauma (injury) predisposes to paralysis following polio infection
Surgeries
- Tonsillectomy – removal of the palatine tonsil; predisposes to bulbar poliomyelitis after contact with the virus.
Medication
- “Vaccine polio” (vaccine-derived poliovirus) by live oral vaccineNote: The inactivated polio vaccine (IPV) confers vaccine protection without the risk of transmission.
Other causes
- Intramuscular injections predispose to paralysis of the affected limb in poliomyelitis
