Australian National Enterovirus Reference Laboratory annual report, 2024

Having been declared polio-free by the World Health Organization (WHO) in 2000, Australia remains at risk of poliovirus importation until the virus is eradicated globally. Australia monitors for poliovirus by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the WHO. Cases of AFP in children are notified to the Australian Paediatric Surveillance Unit or the Paediatric Active Enhanced Disease Surveillance System, and faecal specimens are referred for virological investigation to the National Enterovirus Reference Laboratory. In 2024, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 2.04 non-polio AFP cases per 100,000 children, thereby meeting the WHO's performance criterion for a sensitive surveillance system. Non-polio enteroviruses including enterovirus A71 were identified from clinical specimens collected from 14 AFP cases. Australia also performs enterovirus and wastewater surveillance to complement the clinical surveillance system focussed on children. In 2024, there were 21 different non-polio enterovirus types detected in 764 clinical specimens referred for enterovirus typing, while an ambiguous vaccine-derived poliovirus type 2 was detected through wastewater surveillance. In 2024, there were 99 cases of wild poliovirus reported from the two remaining endemic countries, Afghanistan and Pakistan. Another 319 cases of poliomyelitis due to circulating vaccine-derived poliovirus were reported across 21 countries.