Polio outbreak in Tajikistan is cause for alarm

We are now witnessing the first persistent outbreak of poliomyelitis in the world in a previously certified
polio-free zone. This dreadful disease has no cure and causes paralysis and even death. In April 2010, WHO confirmed that seven children with acute flaccid paralysis in Tajikistan had wild poliovirus type 1. By June 1, a mere five weeks later, over 560 cases of acute flaccid paralysis have been reported, with 183 already laboratory confirmed as WPV-1. This rapidly growing outbreak represents 75% of the world cases of poliomyelitis this year, far outstripping usual hotspots in India and Nigeria.1 How did this happen in the WHO Euro region, a region certified as polio-free since 2002?

The spread of poliovirus can be insidious, because more than 95% of infected people are asymptomatic; however, the virus is shed in stool for up to four to eight weeks, which allows it to spread rapidly, widely and initially silently in unimmunized or underimmunized communities. Spread of the virus can only be prevented if more than 90% of people in a community are vaccinated.

Full CMAJ editorial at: http://www.cmaj.ca/cgi/rapidpdf/cmaj.100831v1