24 Oct 2019
Why do we need a polio laboratory in Australia? Aren’t we polio-free?
Today is World Polio Day, we asked Associate Professor Bruce Thorley head of our WHO Polio Regional Reference Laboratory for his insights into polio in Australia and our region.
“Why do we need a polio laboratory in Australia? Aren’t we polio-free?”
I am often asked those questions when people hear that I actually do work in such a laboratory at the Peter Doherty Institute for Infection and Immunity (Doherty Institute).
While it’s true Australia is free of the wild poliovirus that caused large outbreaks and paralysed thousands of people last century, three countries still remain endemic for wild polio: Afghanistan, Nigeria and Pakistan.
Until the global eradication of wild poliovirus has been certified, all countries remain at risk of a wild poliovirus importation from one of these countries as last occurred in Australia in 2007.
The major symptom of poliovirus infection is acute onset of paralysis in one or more limbs but there are other viral and non-viral causes of paralysis.
Each country must have a reference laboratory to test specimens from cases of suspected polio to confirm or exclude poliovirus as the cause.
Not all countries have the resources to host such a laboratory, which must be accredited by the World Health Organization, and so the polio lab at the Doherty Institute also acts as the national reference laboratory for Brunei Darussalam, the Pacific Island countries and territories and Papua New Guinea. More than 140 laboratories make up the Global Polio Laboratory Network.
I’m also struck by the number of people who tell me they know someone or have a family member who contracted polio.
Most people infected with poliovirus don’t have any symptoms and it took many years for scientists to unravel how the virus is spread, to realise, in fact, there are three types of poliovirus and that it’s possible to prevent the disease through vaccination.
The key to a polio-free world is vaccination, which wasn’t available in Australia until 1956. It is important that high rates of polio vaccination are maintained in all countries to stop transmission of wild poliovirus in the endemic countries and to protect the population of polio-free countries from importations of wild poliovirus or when travelling.
The global eradication of polio is founded on the three pillars of vaccination, surveillance for suspected cases and laboratory testing of specimens.
The number of wild poliovirus cases has decreased from more than 1,000 new cases per day when the program commenced in 1988 to 88 so far in 2019, and all in Afghanistan and Pakistan.
Wild poliovirus type 2 was certified as eradicated in 2015 and eradication of type 3 is expected to be certified this year leaving only type 1 in the endemic countries.
The world is very close to being polio-free.