Annual report of the Australian National Poliovirus Reference Laboratory, 2002

Acute flaccid paralysis is the main clinical manifestation of poliomyelitis. Faecal specimens from cases of acute flaccid paralysis in Australia are referred to the National Poliovirus Reference Laboratory for virus culture to determine if poliovirus is the causative agent. Isolations of poliovirus are tested to determine whether they have characteristics of the Sabin oral polio vaccine virus strains or wild type polioviruses. In 2002, a poliovirus type 3, which tested as Sabin vaccine-like, was isolated from an Australian patient with acute flaccid paralysis. A non-polio enterovirus, Echovirus type 18, was isolated from the faecal specimens of another case of acute flaccid paralysis. In the same period, the laboratory identified 35 Sabin-like polioviruses from 52 referred specimens and isolates from cases without acute flaccid paralysis. Australia is a member nation of the World Health Organization's Western Pacific region that was declared free of endemic wild poliovirus in October 2000. Poliomyelitis remains endemic in three of the WHO regions of the world and wild poliovirus may be re-introduced to Australia. While the number of polio-endemic countries has been reduced to seven, the total number of wild polioviruses identified increased in 2002 compared to 2001 due to a sharp rise in isolations of wild virus from Northern India. Until global eradication of poliomyelitis is achieved, it is essential that a high level of poliovirus vaccination coverage, and surveillance for cases of acute flaccid paralysis, be maintained in Australia.