Poliomyelitis
Poliomyelitis is caused by infection with a poliovirus, one of group of viruses called enteroviruses. Enteroviruses are spread by the faecal-oral route. They come from a family called picorna viruses, all contain RNA (Ribonucleic Acid) as their genetic material, and are responsible for a number of different disorders besides polio. (Coxsackie viruses cause meningitis, gastroenteritis, pericarditis and bornholm disease, together with hand foot and mouth disease in children; echoviruses cause meningitis, and lots affect the respiratory tract producing symptoms of summer colds). Polio used to be widespread throughout the world. About seven days after infection the virus affects nerve cells in the spinal cord, causing paralysis of the muscles that the nerves supply. Infection by what is described as ‘wild polio’ is now extremely rare in the Western World as result of vaccination using an attenuated (i.e. e weakened) live virus given orally. It does occur, rarely, as a result of unvaccinated parents being infected by their vaccinated child. Some recommend that vaccination be repeated every 10 years, and that parents should be vaccinated at the same time as their children.
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