Acute Flaccid Paralysis in Australian Children from 2007 to 2017.

INTRODUCTION: Acute flaccid paralysis (AFP) surveillance continues globally as part of the World Health Organization's goal to eradicate poliomyelitis. The Australian Paediatric Surveillance Unit (APSU), Paediatric Active Enhanced Disease Surveillance (PAEDS) network, and National Enterovirus Reference Laboratory (NERL) collaborate in AFP surveillance in Australia, capturing and reviewing cases of AFP for all aetiologies in order to exclude poliovirus. We aimed to describe the AFP epidemiology in childhood over an 11 year period. METHODS: Data were reported nationally by paediatricians via prospective APSU surveillance, PAEDS surveillance nurses at five tertiary paediatric hospitals and NERL from 2007 to 2017. Children aged 0-15 years with AFP were included. We combined APSU, PAEDS, and NERL datasets, analysed epidemiological trends, and described clinical features and investigations for major diagnoses. RESULTS: Of 590 AFP-compatible cases, 49% were male; 47% were aged 0-4 years, 9% aged <1 year. Annual incidence of AFP was 1.3 cases per 100,000 children aged <15 years. Lower limb paralysis was the most frequent presenting symptom. The most frequent diagnoses were Guillain-Barre syndrome (GBS; 36%), transverse myelitis (TM; 17%), and acute disseminated encephalomyelitis (ADEM; 15%). No secular trend was seen in frequency of AFP cases nor amongst major diagnoses. Seasonality was observed with ADEM occurring more frequently in winter. We observed periods of increased AFP frequency in 2013 and 2016, coinciding with increased reporting of non-polio anterior horn cell disease (AHCD) and detection of non-polio enterovirus (NPEV). CONCLUSIONS: Estimated incidence of GBS, ADEM, and TM in Australian children was comparable with international rates. There was stable incidence of AFP in Australian children between 2007 and 2017. GBS, ADEM, and TM are the major causes of AFP. We observed clustering of cases associated with NPEV that emphasises a need for ongoing vigilance in surveillance given continue emerging infectious disease threats.

Polio - The old foe and new challenges: An update for clinicians.

The Global Polio Eradication Initiative since 1988 has seen the impact of poliovirus decline from frequent global epidemics in the early 1900s to being now only endemic in two countries today. Global vaccination programmes and surveillance for the disease have resulted in the landmark eradication of two of the three poliovirus strains in the last 5 years. Australia continues to contribute to global surveillance efforts for the disease via the Australian Paediatric Surveillance Unit and the Paediatric Active Enhanced Disease Surveillance Network, which aim to detect cases of acute flaccid paralysis in children, the key clinical feature of poliomyelitis. Today, in the era of the polio 'endgame', there is growing recognition of non-polio enteroviruses causing paralytic diseases that are polio-like, particularly in children, with an increased need for awareness and vigilance by paediatric clinicians.

Acute flaccid myelitis - has it gone unrecognised in Australian children?

We have identified a previously unrecognised cluster of a newly recognised condition - acute flaccid myelitis (AFM) - among acute flaccid paralysis (AFP) cases identified by the Australian Paediatric Active Enhanced Disease Surveillance Network (PAEDS) 2007-2017. In the 12 months before and after detection of enterovirus D68 (EV-D68) from a single AFP case in April 2016, 24 of 97 notified cases of AFP were found to be clinically compatible with AFM; of these 24 cases, ten, clustered in early 2016, met magnetic resonance imaging (MRI) criteria for AFM. Detection of emerging enteroviruses requires collection of respiratory, cerebrospinal fluid and stool specimens, and should be routine practice for all AFP cases.