Australian National Enterovirus Reference Laboratory annual report, 2022.

Abstract: Australia monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (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 2022, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.69 non-polio AFP cases per 100,000 children, thereby meeting the WHO's performance criterion for a sensitive surveillance system. The non-polio enteroviruses coxsackievirus A2, coxsackievirus A6, coxsackievirus A10, echovirus 18, enterovirus A71 and enterovirus C96 were identified from clinical specimens collected from AFP cases. Australia also performs enterovirus and environmental surveillance to complement the clinical system focussed on children. In 2022, thirty cases of wild poliovirus were reported from three countries (Afghanistan, Mozambique and Pakistan); 24 countries also reported cases of poliomyelitis due to circulating vaccine-derived poliovirus.

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.

Concurrent outbreaks of circulating vaccine-derived poliovirus types 1 and 2 affecting the Republic of the Philippines and Malaysia, 2019-2021.

Concurrent outbreaks of circulating vaccine-derived poliovirus serotypes 1 and 2 (cVDPV1, cVDPV2) were confirmed in the Republic of the Philippines in September 2019 and were subsequently confirmed in Malaysia by early 2020. There is continuous population subgroup movement in specific geographies between the two countries. Outbreak response efforts focused on sequential supplemental immunization activities with monovalent Sabin strain oral poliovirus vaccine type 2 (mOPV2) and bivalent oral poliovirus vaccines (bOPV, containing Sabin strain types 1 and 3) as well as activities to enhance poliovirus surveillance sensitivity to detect virus circulation. A total of six cVDPV1 cases, 13 cVDPV2 cases, and one immunodeficiency-associated vaccine-derived poliovirus type 2 case were detected, and there were 35 cVDPV1 and 31 cVDPV2 isolates from environmental surveillance sewage collection sites. No further cVDPV1 or cVDPV2 have been detected in either country since March 2020. Response efforts in both countries encountered challenges, particularly those caused by the global COVID-19 pandemic. Important lessons were identified and could be useful for other countries that experience outbreaks of concurrent cVDPV serotypes.

Australian Paediatric Surveillance Unit (APSU) Annual Surveillance Report 2021.

Abstract: The Australian Paediatric Surveillance Unit (APSU) has been conducting surveillance of rare communicable and non-communicable conditions in children since its inception in 1993. In this report, the results are described of surveillance of ten communicable diseases (and complications) for 2021, including the numbers of cases and incidence estimates; demographics; clinical features; and management and short-term outcomes. The included diseases are: acute flaccid paralysis (AFP); congenital cytomegalovirus (CMV); neonatal herpes simplex virus (HSV) infection; paediatric human immunodeficiency virus (HIV) infection; perinatal exposure to HIV; severe complications from influenza; juvenile-onset respiratory papillomatosis (JoRRP); congenital rubella syndrome; congenital varicella syndrome; and neonatal varicella infection. In 2021, cases of JoRRP were reported to the APSU for the first time since 2017, indicating potential gaps in HPV vaccination. AFP surveillance by APSU again contributed to Australia achieving a minimum target incidence of one AFP case per 100,000 children aged < 15 years. There were no cases of children with severe complications of influenza. No cases of varicella or congenital rubella were reported; however, at-risk populations, especially young migrant and refugee women from countries without universal vaccination programs, need to be screened and prioritised for vaccination prior to pregnancy. Cases of perinatal exposure to HIV continue to increase; however, the rate of mother-to-child-transmission remains at low levels due to the use of effective intervention strategies. Case numbers of congenital CMV and neonatal HSV remain steady in the absence of vaccines, prompting the need for greater awareness and education, with recent calls for target screening of at-risk infants for congenital CMV.

Australian National Enterovirus Reference Laboratory annual report, 2021.

Australia monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (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 2021, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.31 non-polio AFP cases per 100,000 children, thereby meeting the WHO's performance criterion for a sensitive surveillance system. The non-polio enteroviruses coxsackievirus A4, coxsackievirus A10, coxsackievirus A13 and enterovirus A71 were identified from clinical specimens collected from AFP cases. Australia also performs enterovirus and environmental surveillance to complement the clinical system focussed on children. In 2021, there were five cases of wild poliovirus reported from the two remaining endemic countries: Afghanistan and Pakistan. Including Afghanistan and Pakistan, 22 countries also reported cases of AFP due to circulating vaccine-derived poliovirus.

Using the Acute Flaccid Paralysis Surveillance System to Identify Cases of Acute Flaccid Myelitis, Australia, 2000‒2018.

Since 2012, the United States has reported a distinct syndrome of acute flaccid paralysis (AFP) with anterior myelitis, predominantly in children. This polio-like syndrome was termed acute flaccid myelitis (AFM). Australia routinely conducts AFP surveillance to exclude poliomyelitis. We reviewed 915 AFP cases in Australia for children <15 years of age during 2000‒2018 and reclassified a subset to AFM by using the US Council of State and Territorial Epidemiologists case definition. We confirmed 37 AFM cases by using magnetic resonance imaging findings and 4 probable AFM cases on the basis of cerebrospinal fluid pleocytosis. Nonpolio enteroviruses were detected in 33% of AFM cases from which stool samples were tested. Average annual AFM incidence was 0.07 cases/100,000 person-years in children <15 years of age. AFM occurred sporadically in Australia before 2010 but regularly since then, indicating sustained, albeit rare, clinical manifestation in children. The AFP surveillance system in Australia is well-positioned to identify future AFM cases.

Australian National Enterovirus Reference Laboratory annual report, 2020.

ABSTRACT: Australia monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (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 2020, no cases of poliomyelitis were reported from clinical surveillance; Australia reported 1.09 non-polio AFP cases per 100,000 children, thereby meeting the WHO's performance criterion for a sensitive surveillance system. The non-polio enteroviruses coxsackievirus A10 and coxsackievirus A16 were identified from clinical specimens collected from AFP cases. Australia also performs enterovirus surveillance and environmental surveillance to complement the clinical system focussed on children. In 2020, there were 140 cases of wild poliovirus reported from the two remaining endemic countries: Afghanistan and Pakistan. Another 28 countries reported cases of circulating vaccine-derived poliovirus.

Australian Paediatric Surveillance Unit (APSU) Annual Surveillance Report 2020.

ABSTRACT: For 27 years, national prospective data on selected rare childhood diseases have been collected monthly by the Australian Paediatric Surveillance Unit (APSU) from paediatricians and other clinical specialists who report cases in children aged up to 16 years. We report here the annual results of APSU surveillance in 2020 for ten rare communicable diseases and complications of communicable diseases, namely: acute flaccid paralysis (AFP); congenital cytomegalovirus (CMV) infection; neonatal herpes simplex virus (HSV) infection; perinatal exposure to human immunodeficiency virus (HIV); paediatric HIV infection; severe complications of seasonal influenza; juvenile onset recurrent respiratory papillomatosis (JoRRP); congenital rubella syndrome; congenital varicella syndrome; and neonatal varicella infection. We describe the results for each disease in the context of the total period of study, including demographics, clinical characteristics, treatment and short-term outcomes. Despite challenges presented by the coronavirus disease 2019 (COVID-19) pandemic in 2020, more than 1,400 paediatricians reported regularly to the APSU and an overall monthly reporting rate of > 90% was achieved. The minimum AFP target of 1 case per 100,000 children aged less than 15 years was achieved and there were few cases of vaccine-preventable diseases (JoRRP, rubella, varicella). However, high cases of congenital CMV, neonatal HSV and perinatal exposure to HIV persist. There were no severe complications of seasonal influenza reported for the first time in 13 years. This is consistent with other surveillance data reporting a decline of influenza and other communicable diseases in 2020, and likely reflects the wider effects of public health measures to reduce transmission of SARS-CoV-2 in the Australian community.

Passive Sampling of SARS-CoV-2 for Wastewater Surveillance.

The shedding of pathogens by infected humans enables the use of sewage monitoring to conduct wastewater-based epidemiology (WBE). Although most WBE studies use data from large sewage treatment plants, timely data from smaller catchments are needed for targeted public health action. Traditional sampling methods, like autosamplers or grab sampling, are not conducive to quick ad hoc deployments and high-resolution monitoring at these smaller scales. This study develops and validates a cheap and easily deployable passive sampler unit, made from readily available consumables, with relevance to the COVID-19 pandemic but with broader use for WBE. We provide the first evidence that passive samplers can be used to detect SARS-CoV-2 in wastewater from populations with low prevalence of active COVID-19 infections (0.034 to 0.34 per 10,000), demonstrating their ability for early detection of infections at three different scales (lot, suburb, and city). A side by side evaluation of passive samplers (n = 245) and traditionally collected wastewater samples (n = 183) verified that the passive samplers were sensitive at detecting SARS-CoV-2 in wastewater. On all 33 days where we directly compared traditional and passive sampling techniques, at least one passive sampler was positive when the average SARS-CoV-2 concentration in the wastewater equaled or exceeded the quantification limit of 1.8 gene copies per mL (n = 7). Moreover, on 13 occasions where wastewater SARS-CoV-2 concentrations were less than 1.8 gene copies per mL, one or more passive samplers were positive. Finally, there was a statistically significant (p < 0.001) positive relationship between the concentrations of SARS-CoV-2 in wastewater and the levels found on the passive samplers, indicating that with further evaluation, these devices could yield semi-quantitative results in the future. Passive samplers have the potential for wide use in WBE with attractive feasibility attributes of cost, ease of deployment at small-scale locations, and continuous sampling of the wastewater. Further research will focus on the optimization of laboratory methods including elution and extraction and continued parallel deployment and evaluations in a variety of settings to inform optimal use in wastewater surveillance.

Decreased incidence of enterovirus and norovirus infections during the COVID-19 pandemic, Victoria, Australia, 2020.

ABSTRACT: Significant reductions in the incidence of enteroviruses and noroviruses, both transmitted primarily by the faecal-oral route, were noted in 2020 compared to the previous decade, in Victoria, Australia. The enterovirus specimen positivity rate was reduced by 84.2% in 2020, while the norovirus outbreak positivity rate declined by 49.0%. The most likely explanation for these reductions is the concurrence of social restrictions, physical distancing, personal hygiene awareness and international and domestic border closures in response to the COVID-19 pandemic.

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.

Australian Paediatric Surveillance Unit (APSU) Annual Surveillance Report 2019.

The Australian Paediatric Surveillance Unit (APSU) has been prospectively collecting national data on rare childhood conditions since 1993, with monthly reporting of cases by paediatricians. In this report we describe annual results from studies for ten communicable diseases and complications of communicable diseases that were conducted using APSU surveillance in 2019 and place these in an historic context. Results are reported on acute flaccid paralysis, congenital cytomegalovirus infection, neonatal herpes simplex virus infection, perinatal exposure to HIV, paediatric HIV infection, severe complications of seasonal influenza, juvenile onset recurrent respiratory papillomatosis (JoRRP), congenital rubella syndrome, congenital varicella syndrome and neonatal varicella infection. APSU provides rich clinical data to complement data collected from other surveillance systems and to improve understanding and response to rare childhood infections.

Australian National Enterovirus Reference Laboratory annual report, 2015.

Australia conducts surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years as recommended by the World Health Organization (WHO) as the main method to monitor its polio-free status. 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 2015, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.2 non-polio AFP cases per 100,000 children, meeting the WHO performance criterion for a sensitive surveillance system. Two non-polio enteroviruses, enterovirus A71 and coxsackievirus B3, were identified from clinical specimens collected from AFP cases. Australia complements the clinical surveillance program with enterovirus and environmental surveillance for poliovirus. Two Sabin-like polioviruses were isolated from sewage collected in Melbourne in 2015, which would have been imported from a country that uses the oral polio vaccine. The global eradication of wild poliovirus type 2 was certified in 2015 and Sabin poliovirus type 2 will be withdrawn from oral polio vaccine in April 2016. Laboratory containment of all remaining wild and vaccine strains of poliovirus type 2 will occur in 2016 and the National Enterovirus Reference Laboratory was designated as a polio essential facility. Globally, in 2015, 74 cases of polio were reported, only in the two remaining countries endemic for wild poliovirus: Afghanistan and Pakistan. This is the lowest number reported since the global polio eradication program was initiated.

Australian National Enterovirus Reference Laboratory annual report, 2016.

Australia monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (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 2016, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.38 non-polio AFP cases per 100,000 children, meeting the WHO performance criterion for a sensitive surveillance system. Several non-polio enteroviruses, coxsackievirus A6, enterovirus A71, enterovirus A74 and enterovirus D68, were identified from clinical specimens collected from AFP cases. The global withdrawal of Sabin poliovirus type 2 from oral polio vaccine occurred in April 2016. This event represents the start of the polio endgame with an increased focus on the laboratory containment of all remaining wild and vaccine strains of poliovirus type 2. The National Enterovirus Reference Laboratory was designated as a polio essential facility as part of this process. In 2016, 37 cases of wild polio were reported with three countries remaining endemic: Afghanistan, Nigeria and Pakistan. Nigeria was declared polio-free in 2015, after 12 months without detection of wild poliovirus, but was reinstated as an endemic country after the reporting of four cases in August 2016. This is a salient reminder of the need to maintain sensitive surveillance for poliovirus until global eradication is certified.

Australian National Enterovirus Reference Laboratory annual report, 2017.

Australia monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (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 2017, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.33 non-polio AFP cases per 100,000 children, meeting the WHO performance criterion for a sensitive surveillance system. Three non-polio enteroviruses, coxsackievirus B1, echovirus 11 and enterovirus A71, were identified from clinical specimens collected from AFP cases. Australia established enterovirus and environmental surveillance systems to complement the clinical system focussed on children and an ambiguous vaccine-derived poliovirus type 2 was isolated from sewage in Melbourne. In 2017, 22 cases of wild polio were reported with three countries remaining endemic: Afghanistan, Nigeria and Pakistan.

Australian National Enterovirus Reference Laboratory annual report, 2018.

Australia monitors its polio-free status by conducting surveillance for cases of 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 2018, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.24 non-polio AFP cases per 100,000 children, meeting the WHO performance criterion for a sensitive surveillance system. Several non-polio enteroviruses, coxsackievirus A4, coxsackievirus B1, echovirus 9, echovirus 30, enterovirus D68 and enterovirus A71, were identified from clinical specimens collected from AFP cases. Australia also performs enterovirus and environmental surveillance to complement the clinical system focussed on children. In 2018, 33 cases of wild polio were reported with three countries remaining endemic: Afghanistan, Nigeria and Pakistan.

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.