Poliomyelitis

A highly contagious picornavirus, faecal-oral transmission — specifically infects spinal cord anterior horn cells. 95% of infections are asymptomatic. Rare in Australia due to vaccination.

Clinical stages

1. Flu-like prodrome — fever, sore throat.
2. Pre-paralytic stage — nausea, vomiting, headache, stiff neck.
3. Paralytic stage (0.1% of infections) — LMN lesion (flaccid paralysis), may include spinal polio (especially lower limbs) and/or bulbar polio ± respiratory failure. No sensory loss. Two severity tiers: minor (recovery within days) and major.

Investigations

PCR of throat and faeces; serology; CSF (lymphocytic leucocytosis).

Management

Symptomatic polio needs hospital referral. Vaccination is the mainstay of prevention.

Post-polio syndrome — new muscle weakness and pain, 20–40 years after the primary infection, from dysfunction of surviving motor neurons. Refer to a specialist unit.