Paediatric Active Enhanced Disease Surveillance (PAEDS) 2017 and 2018: Prospective hospital-based surveillance for serious paediatric conditions

The seroprevalence of SARS-CoV-2-specific antibodies in Australian children: A cross-sectional study

BACKGROUND

Following reduction of public health and social measures concurrent with SARS-CoV-2 Omicron emergence in late 2021 in Australia, COVID-19 case notification rates rose rapidly. As rates of direct viral testing and reporting dropped, true infection rates were most likely to be underestimated.

OBJECTIVE

To better understand infection rates and immunity in this population, we aimed to estimate SARS-CoV-2 seroprevalence in Australians aged 0-19 years.

METHODS

We conducted a national cross sectional serosurvey from June 1, 2022, to August 31, 2022, in children aged 0-19 years undergoing an anesthetic procedure at eight tertiary pediatric hospitals. Participant questionnaires were administered, and blood samples tested using the Roche Elecsys Anti-SARS-CoV-2 total spike and nucleocapsid antibody assays. Spike and nucleocapsid seroprevalence adjusted for geographic and socioeconomic imbalances in the participant sample compared to the Australian population was estimated using multilevel regression and poststratification within a Bayesian framework.

RESULTS

Blood was collected from 2,046 participants (median age: 6.6 years). The overall adjusted seroprevalence of spike-antibody was 92.1% (95% credible interval (CrI) 91.0-93.3%) and nucleocapsid-antibody was 67.0% (95% CrI 64.6-69.3). In unvaccinated children spike and nucleocapsid antibody seroprevalences were 84.2% (95% CrI 81.9-86.5) and 67.1% (95%CrI 64.0-69.8), respectively. Seroprevalence was similar across geographic remoteness index and socioeconomic quintiles. Nucleocapsid antibody seroprevalence increased with age while the point seroprevalence of the spike antibody seroprevalence decreased in the first year of life and then increased to 97.8 (95% Crl 96.1-99.2) by 12-15 years of age.

CONCLUSION

Most Australian children and adolescents aged 0-19 years, across all jurisdictions were infected with SARS-CoV-2 by August 2022, suggesting rapid and uniform spread across the population in a very short time period. High seropositivity in unvaccinated children informed COVID-19 vaccine recommendations in Australia.

Review of the health impact of the oral rotavirus vaccine program in children under 5 years in Australia: 2006 - 2021

Oral rotavirus vaccines were incorporated into the National Immunisation Program (NIP) for all Australian infants in July 2007. Initially each of the eight jurisdictions implemented Rotarix or RotaTeq rotavirus vaccine, however from July 2017 all states and territories have administered Rotarix only. This review evaluates the health impact of the oral rotavirus vaccine program for Australian children less than 5 years old over the first 15 years of the rotavirus vaccine program, observing long-term changes in rotavirus-related health care attendances, public health notifications, and vaccine effectiveness and safety data for both Rotarix and RotaTeq rotavirus vaccines. We searched Medline for studies published between January 2006 and May 2022 using the search terms 'rotavirus', 'rotavirus vaccine' and 'Australia'. Of 491 items identified, 76 items - 36 peer-reviewed articles and 40 reports - were included in the review. We found evidence that the introduction of the oral rotavirus vaccine program in Australia was associated with a prompt reduction in rotavirus-coded and all-cause gastroenteritis hospitalisations of vaccine-eligible children. In the context of less complete coverage, reduced vaccine timeliness and lower vaccine effectiveness, a less substantial and inconsistent reduction in severe rotavirus disease was observed among Aboriginal and Torres Strait Islander children, particularly those living in rural and remote northern Australia. Additional studies report no evidence for the emergence of non-vaccine serotypes and/ or replacement serotypes in Australia during the vaccine era. While the health impact for young children and consequent cost-savings of the oral rotavirus vaccine program have been high, it is important to find strategies to improve rotavirus vaccine impact for Aboriginal and Torres Strait Islander populations to ensure health benefits for all Australian children.

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.

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.

Paediatric Active Enhanced Disease Surveillance (PAEDS) 2019: Prospective hospital-based surveillance for serious paediatric conditions

Introduction

The Paediatric Active Enhanced Disease Surveillance (PAEDS) network is an Australian hospital-based active surveillance system employing prospective case ascertainment for selected serious childhood conditions, particularly vaccine preventable diseases and potential adverse events following immunisation (AEFI). This report presents surveillance data for 2019.

Methods

Specialist nurses screened hospital admissions, emergency department records, laboratory and other data on a daily basis in seven paediatric tertiary referral hospitals across Australia, to identify children with the conditions under surveillance. Standardised protocols and case definitions were used across all sites. In 2019, the conditions under surveillance comprised: acute flaccid paralysis (AFP; a syndrome associated with poliovirus infection), acute childhood encephalitis (ACE), influenza, intussusception (IS; a potential AEFI with rotavirus vaccines), pertussis, varicella-zoster virus infection (varicella and herpes zoster), invasive meningococcal and invasive Group A streptococcus diseases and two new conditions, Kawasaki disease and gram-negative bloodstream infections. An additional social research component continued to evaluate parental attitudes to influenza vaccination.

Results

PAEDS captured 2,701 cases for 2019 across all conditions under surveillance. Key outcomes of PAEDS included: contribution to national AFP surveillance to reach the World Health Organization reporting targets for detection of poliomyelitis cases; demonstration of high influenza activity in 2019 and influenza-associated deaths in ACE cases; identification of key barriers to influenza vaccination of children hospitalised for acute respiratory illness; reporting of all IS cases associated with vaccine receipt to relevant state health department; and showing a further reduction nationally in varicella cases. Enhanced pertussis surveillance continued to capture controls to support vaccine efficacy estimation. Invasive meningococcal disease surveillance showed predominance of serotype B and a reduction in cases nationally. Surveillance for invasive group A streptococcus captured severe cases in children. Monitoring of Kawasaki disease incidence and gram-negative bloodstream infections commenced.

Conclusions

PAEDS continues to provide unique policy-relevant data on serious paediatric conditions using sentinel hospital-based enhanced surveillance. Keywords: paediatric, surveillance, child, hospital, vaccine preventable diseases, adverse event following immunisation, acute flaccid paralysis, encephalitis, influenza, intussusception, pertussis, varicella zoster virus, meningococcal, group A streptococcus, Kawasaki, bloodstream infections.

Barriers to influenza vaccination of children hospitalised for acute respiratory illness: A cross-sectional survey

AIM

To identify barriers to influenza vaccination of children hospitalised for acute respiratory illness in Australia.

METHODS

A total of 595 parents of children hospitalised with acute respiratory illness across five tertiary hospitals in 2019 participated in an online survey. Multivariate logistic regression identified factors most strongly associated with influenza vaccination barriers.

RESULTS

Odds of influenza vaccination were lower with lack of health-care provider (HCP) recommendation (adjusted odds ratio (aOR) 0.18; 95% confidence interval (CI): 0.08-0.38); if parents had difficulties (aOR 0.19; 95% CI: 0.08-0.47) or were 'neutral' (aOR 0.23; 95% CI: 0.06-0.82) in remembering to make an appointment; and if parents had difficulties (aOR 0.21; 95% CI: 0.07-0.62) or were 'neutral' (aOR 0.24; 95% CI: 0.07-0.79) regarding getting an appointment for vaccination. Odds were also lower if parents did not believe (aOR 0.27; 95% CI: 0.08-0.90) or were 'neutral' (aOR 0.15; 95% CI: 0.04-0.49) regarding whether the people most important to them would have their child/ren vaccinated against influenza. Children had lower odds of vaccination if parents did not support (aOR 0.09; 95% CI: 0.01-0.82) or were ambivalent (aOR 0.09; 95% CI: 0.01-0.56) in their support for influenza vaccination. Finally, lack of history of influenza vaccination of child (aOR 0.38; 95% CI: 0.18-0.81) and respondent (aOR 0.25; 95% CI: 0.11-0.56) were associated with lack of receipt of influenza vaccine before admission for acute respiratory infection.

CONCLUSIONS

Assisting parents in remembering and accessing influenza vaccination and encouraging health-care providers to recommend vaccination may increase uptake.

Australian National Enterovirus Reference Laboratory annual report, 2019

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. 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 2019, no cases of poliomyelitis were reported from clinical surveillance and Australia reported 1.34 non-polio AFP cases per 100,000 children, meeting the World Health Organization’s performance criterion for a sensitive surveillance system. The non-polio enteroviruses coxsackievirus A2, coxsackievirus A16, echovirus 9, 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 2019, 175 cases of wild polio were reported, with three countries remaining endemic: Afghanistan, Nigeria and Pakistan.

COVID-19, Australia: Epidemiology Report 25 (Fortnightly reporting period ending 13 September 2020)

Cumulatively to 13 September there have been 26,753 case notifications and 674 deaths. The number of new cases reported nationally this fortnight was 764, a 61% decrease from the previous fortnight (1,948). On average this represented 55 cases diagnosed each day over the reporting period, a decrease from 125 cases per day over the previous reporting period. 84% of all cases (640/764) were reported in Victoria, with a smaller number of cases reported from New South Wales (95), Queensland (22), Western Australia (4) and South Australia (3). In Victoria, 97% of cases (621) were locally acquired and were mostly reported from residential aged care facilities; and 3% of cases (19) were reported as under investigation at the date of extract this reporting period. Excluding Victoria, 124 cases were reported nationally, 32% (40) were overseas acquired; 65% (81) were locally acquired, predominantly in New South Wales (62); and 2% (3) of cases were under investigation at this time, all reported in Queensland. The continued decrease in new cases observed this fortnight in Victoria is likely associated with the enhanced public health measures that are currently in place in Victoria. Locally-acquired cases which were predominantly associated with several interconnected clusters continued to be reported in New South Wales. In Queensland, 82% of cases (18/22) were reported as locally acquired from two clusters associated with immigration centres or correctional facilities. A total of 6 deaths were reported from cases diagnosed in this reporting period-all from Victoria, all aged 50 years or older, three male and three female. Although testing rates have declined gradually over the past month they remain high at 14.5 tests per 1,000 population per week. The overall positivity rate for the reporting period was 0.13%. Victoria reported a positivity rate of 0.39% for this reporting period while in all other jurisdictions the positivity rate was 0.05% or lower. For this report, "In focus" is paediatric inflammatory multisystem syndrome temporally associated with SARS-COV-2 (PIMS-TS). A review of Australia's public health response to COVID-19 (as at 13 September 2020) is at Appendix A.