POLIO

Poliomyelitis is an enterovirus of the Picornavirus family that causes a GI infection that spreads to the CNS. Polio has almost been eradicated from planet Earth, but it still stubbornly lingers in isolated rural communities in Pakistan and Afghanistan. 

What does the typical patient look like?

A child from Pakistan or Afghanistan

Wait, it's a GI infection?

Yep. It causes mild gastroenteritis or a sore throat. In less than 1% of cases, polio can spread to the spine. There it can damage the nervous system.

How does it damage the nervous system?

Polio kills α-motor neurons. That causes flaccid paralysis (legs > arms).

Is it deadly?

Yep. 10% of patients who develop neurological symptoms die (from respiratory paralysis). 

Diagnosis?

↑Protein and ↑WBCs in the CSF. 

Treatment?

Supportive. Iron lungs were used to assist the muscles of respiration. 

Prevention?

The polio vaccine. Extra polio vaccine info: the dead attenuated vaccine is used in the developed world. That’s because it can’t cause sporadic cases of polio. But it doesn’t store well. So the live attenuated vaccine is used more often in the developing world. It’s super cheap, easy to store and comes as a pill. But… it can theoretically cause polio. In the developed world, the inactivated vaccine is preferred.