COVID ‐19 in New South Wales children during 2021: severity and clinical spectrum

Hospital-based cross-sectional study on the clinical characteristics of children with severe acute respiratory infections in Hungary

BACKGROUND

Severe acute respiratory infection (SARI) is a major cause for hospital admission and associated with high mortality among children worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza viruses and respiratory syncytial virus (RSV) are the most frequently identified pathogens in children with SARI. The duration of care can be affected by the type of infection and patient characteristics. Therefore, the objective of this study was to identify factors affecting the length of hospitalization in children infected with SARS-CoV-2, influenza A and RSV.

METHODS

We collected data on 713 children with SARI from the medical databases of a university hospital in Hungary. To examine whether there is a difference in the length of hospitalization in children with the SARI Kruskal-Wallis test was performed. To determine the factors that may have an impact on the duration of care a multiple logistic regression analysis was executed.

RESULTS

Our results showed that among RSV infected patients the proportions of children requiring intensive care (8.94%), mechanical ventilation (8.94%) and oxygen therapy (13.01%) and suffering from pneumonia (29.27%) were larger than among cases with SARS-CoV-2 and influenza A infection. Considering the age distribution and the duration of care in children with SARI, cases with RSV were significantly younger (p < 0.001) and stayed longer in the hospital (median: 5 days, IQR: 4-7 days, p < 0.001) than those with SARS-CoV-2 and influenza A virus. Multiple logistic regression analysis showed that RSV infection (adjusted odds ratio (aOR): 3.25, 95% confidence interval (CI): 1.43-7.38; p = 0.005), pneumonia (aOR: 3.65, 95% CI: 2.14-6.24; p < 0.001), mechanical ventilation or oxygen therapy (aOR: 3.23, 95% CI: 1.29-8.11; p = 0.012) and underlying illnesses (aOR: 2.39, 95% CI: 1.35-4.23; p = 0.003) significantly increased the odds of hospitalization for more than 4 days.

CONCLUSIONS

Our research showed that of the viruses causing SARI, RSV had the greatest clinical relevance, contributing to hospital stays of more than 4 days in a large share of paediatric patients below 1 year of age. Our results supply new information on children with SARI, and provide evidence for health policy makers to allocate additional resources to hospitals during SARI epidemics.

Clinical characteristics and outcomes of neonatal SARS-CoV-2 infection after the release of the epidemic situation of COVID-19

BACKGROUND

With the release of the coronavirus disease 2019 (COVID-19) pandemic in late 2022 in China, the number of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) roared, including neonatal cases. However, there were few studies on neonatal COVID-19, especially multi-center case reports. This study aimed to explore clinical characteristics and short-term outcomes of neonatal COVID-19 in China.

METHODS

We reviewed 187 cases of neonatal COVID-19 between December 11, 2022, and January 12, 2023. The diagnosis was assessed by symptoms, laboratory tests, X-ray manifestations, and diagnosis code. Clinical characteristics and outcomes were evaluated.

RESULTS

In 187 neonatal cases with COVID-19, 84 (44.9%) had severe SARS-CoV-2 infection. Most patients had confirmed exposure to SARS-CoV-2. Fever and respiratory symptoms were common (75.4% and 71.7%, respectively). Severe patients were more likely to have high alanine transaminase (ALT) (> 40U/L) (11.9% vs. 3.9%) and high N-terminal pro-brain natriuretic peptide (NT-proBNP) (> 2000pg/mL) (38.0% vs. 19.6%), compared with nonsevere ones (P < 0.05). None of the patients received COVID-19-specific medical interventions. A few severe patients received corticosteroids (1.1%), and immunoglobulin (0.5%), respectively. All patients were discharged home after the medical care with a median length of stay (LOS) of four days and none of them met the criteria of multisystem inflammatory syndrome in neonates (MIS-N).

CONCLUSIONS

After the release of the epidemic situation of COVID-19 in late 2022 in China, more neonatal cases with severe COVID-19 had high ALT and NT-proBNP level. Few specific medical interventions were given, and the outcome was satisfying.

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.

Post COVID-19 conditions in an Australian pediatric cohort, 3 months following a Delta outbreak

BACKGROUND

Pediatric long COVID remains incompletely understood with scant Australian data available. We aimed to assess the impacts of the 2021 Delta variant of SARS-CoV-2 outbreak on symptoms and functioning 12 weeks post-acute infection in a cohort of children and adolescents.

METHODS

The parents/carers of 11,864 patients with PCR-confirmed SARS-CoV-2 were invited, via email or text message, to complete an online survey assessing symptoms and functional impairment.

FINDINGS

1731 (17.6%) responded to the survey. 203 (11.7%) reported continued symptoms and/or functional impairment which were flagged for clinical review, all others reported recovery. Of the 169 subsequently clinically reviewed, 63 had already recovered (37.3%) and 17 had exacerbation of pre-existing condition(s) (10.1%); 63 (37.3%) were diagnosed with a Post COVID Condition (PCC). Of these, 21 (12.4%) were considered to have features compatible with the United Kingdom consensus cases definition for Long COVID.

INTERPRETATION

During an outbreak of SARS-CoV-2 an online questionnaire with subsequent clinical review revealed self-reported non-recovery at 12 weeks in a minority of cases, with a spectrum of features. Long COVID comprised only a subset of cases with self-reported non-recovery, and is infrequent in children and adolescents, but still comprises a likely significant burden that warrants attention.

IMPACT

Our study provides the only comprehensive estimate of the frequency and spectrum of post-COVID conditions in children from Australia. The high frequency of self-reported recovery, and low frequency of Long COVID compatible illness adds to the literature from other settings. Risk factors for post-COVID conditions in children are identified and include: age >11 year, and previous medical co-morbidity.

Prevalence, risk factors, and outcomes of secondary infections among hospitalized patients with COVID-19 or post-COVID-19 conditions in Victoria, 2020-2023

OBJECTIVES

Estimates of secondary infections are variedly reported, with few studies done in Australia. We investigated the occurrence and impact of secondary infections complicating COVID-19 and post-COVID-19 admissions in Victoria, Australia, 2020-2023.

METHODS

We used linked population-wide data sets and specific International Classification of Disease, 10th Revision codes to identify and estimate the occurrence of secondary infections. Using hospital/intensive care unit length of stay in negative binomial regression and mortality, we examined the impact of secondary infections.

RESULTS

Secondary infections were identified in 6.9% (13,467 of 194,660) of COVID-19 and post-COVID-19 admissions: 6.0% (11,651 of 194,660) bacterial, 0.9% (1691 of 194,660) viral, and 0.2% (385 of 194,660) fungal. Prevalence was highest during the pre-Delta (10.4%) and Omicron-BA2 (8.1%) periods. Sepsis and pneumonia were the most reported syndromes; the occurrence of sepsis declined gradually over time. The odds of secondary infections were higher among the ≥70-year-olds (adjusted odds ratio (aOR) 3.76, 95% confidence interval [CI] 3.43-4.14, vs 20-29-year-olds), individuals with chronic conditions (aOR 3.15, 95% CI 2.88-3.45, vs those without), the unvaccinated (aOR 1.59, 95% CI 1.45-1.75), and the lowest socioeconomic group (aOR 1.12, 95% CI 1.05-1.19). Patients with secondary infections had 2.43 times longer hospital length of stay and 9.60 times longer intensive care unit length of stay than those without secondary infections. The mortality risk was 2.17 times higher in those with secondary infections.

CONCLUSIONS

Secondary infections occurred in 69 per 1000 COVID-19-associated hospital admissions in Victoria, mostly in high-risk groups, and were associated with severe outcomes.

Real-world utilisation of SARS-CoV-2 rapid antigen testing to enable face-to-face learning in Australian schools, an ecological study

OBJECTIVE

The objective of this study was to describe the use of SARS-CoV-2 rapid antigen testing of COVID-19 contacts in New South Wales schools to determine return to in-person school attendance instead of home quarantine, between 6 November and 21 December 2021.

METHODS

COVID-19 school contacts were required to quarantine for two weeks postexposure to the case. Students who opted into daily rapid antigen testing logged their results in a database, prior to school attendance, and obtained SARS-CoV-2 nucleic amplification acid testing on day 12-16. Secondary attack rates (SARs) in schools utilising rapid antigen testing (Test-to-Stay schools) and those not utilising rapid antigen testing (non-Test-to-Stay school) were calculated.

RESULTS

We identified 9,887 people in 293 schools who reported performing at least one rapid antigen test (RAT). The SAR in RAT schools was 3.4% (95% confidence interval: 2.7-4.1) and non-RAT schools was 2.8% (95% confidence interval: 2.4-3.3). A total of 30,535 school days were preserved through this program.

CONCLUSIONS

The use of RATs preserved in-person learning without a significant increase to SAR.

IMPLICATION FOR PUBLIC HEALTH

Disruptions in face-to-face learning have long-term detrimental impacts on children and adolescents. Rapid antigen testing has been shown to be beneficial to maintain face-to-face learning in Australian schools and may be a useful method to safeguard from school disruptions in future pandemics.

Molecular characterization of SARS-CoV-2 Omicron clade and clinical presentation in children

Since its emergence, SARS-CoV-2 Omicron clade has shown a marked degree of variability and different clinical presentation compared with previous clades. Here we demonstrate that at least four Omicron lineages circulated in children since December 2021, and studied until November 2022: BA.1 (33.6%), BA.2 (40.6%), BA.5 (23.7%) and BQ.1 (2.1%). At least 70% of infections concerned children under 1 year, most of them being infected with BA.2 lineages (n = 201, 75.6%). Looking at SARS-CoV-2 genetic variability, 69 SNPs were found to be significantly associated in pairs, (phi <  - 0.3 or > 0.3 and p-value < 0.001). 16 SNPs were involved in 4 distinct clusters (bootstrap > 0.75). One of these clusters (A23040G, A27259C, T23617G, T23620G) was also positively associated with moderate/severe COVID-19 presentation (AOR [95% CI] 2.49 [1.26-4.89] p-value: 0.008) together with comorbidities (AOR [95% CI] 2.67 [1.36-5.24] p-value: 0.004). Overall, these results highlight the extensive SARS-CoV-2 Omicron circulation in children, mostly aged < 1 year, and provide insights on viral diversification even considering low-abundant SNPs, finally suggesting the potential contribution of viral diversification in affecting disease severity.

West Australian parents' views on vaccinating their children against COVID-19: a qualitative study

BACKGROUND

Australian children and adolescents were among the last local cohorts offered COVID-19 vaccines. Despite promising initial uptake, coverage subsequently plateaued, requiring further efforts to improve access and build parents' recognition of the importance of COVID-19 vaccination. We sought to understand West Australian (WA) parents' willingness to vaccinate their children to inform strategies for improving uptake at the time in which they were becoming eligible.

METHODS

We undertook in-depth qualitative interviews with 30 parents of children aged 5-17 years from June - December 2021. During this period, children aged 12-15 years became eligible for vaccination; children aged 5-11 years became eligible shortly thereafter. Data were thematically analysed in NVivo.

RESULTS

Most parents intended on vaccinating their children once eligible. Parents sought to protect their children, to protect the community, to resume travel, and to get back to "normal". They reflected that vaccination against key infectious threats is a routine activity in childhood. Some were concerned about the vaccine, particularly mRNA vaccines, being new technology or impacting fertility. "Wait-awhiles" wanted to see what other parents would do or were delaying until they felt that there was a higher risk of COVID-19 in WA. Most parents of younger children wanted their child to be vaccinated at the general practice clinic due to familiarity and convenience. Parents were particularly eager for clear and consistent messaging about vaccination of children and adolescents, including safety, importance, scientific evidence, and personal stories.

CONCLUSION

For future pandemic vaccinations pertaining to children, governments and health officials need to address parents' concerns and meet their preferences for the delivery of the vaccine program to children and adolescents.

The characteristics of SARS-CoV-2-positive children in Australian hospitals: a PREDICT network study

OBJECTIVES

To examine the clinical characteristics and short term outcomes for children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who presented to Australian hospitals during 2020 and 2021.

DESIGN, SETTING

Retrospective case review study in nineteen hospitals of the Paediatric Research in Emergency Departments International Collaborative (PREDICT) network from all Australian states and territories, including seven major paediatric tertiary centres and eight Victorian hospitals.

PARTICIPANTS

SARS-CoV-2-positive people under 18 years of age who attended emergency departments or were admitted to hospital during 1 February 2020 - 31 December 2021.

MAIN OUTCOME MEASURES

Epidemiological and clinical characteristics, by hospital care type (emergency department [ED] or inpatient care).

RESULTS

A total of 1193 SARS-CoV-2-positive children and adolescents (527 girls, 44%) attended the participating hospitals (107 in 2020, 1086 in 2021). Their median age was 3.8 years (interquartile range [IQR], 0.8-11.4 years); 63 were Aboriginal or Torres Strait Islander people (5%). Other medical conditions were recorded for 293 children (25%), including asthma (86, 7%) and premature birth (68, 6%). Medical interventions were not required during 795 of 1181 ED presentations (67%); children were discharged directly home in 764 cases (65%) and admitted to hospital in 282 (24%; sixteen to intensive care units). The 384 admissions to hospital (including 102 direct admissions) of 341 children (25 infants under one month of age) included 23 to intensive care (6%); the median length of stay was three days (IQR, 1-9 days). Medical interventions were not required during 261 admissions (68%); 44 children received respiratory support (11%) and 21 COVID-19-specific treatments, including antiviral and biologic agents (5%). Being under three months of age (v one year to less than six years: odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.0) and pre-existing medical conditions (OR, 2.5; 95% CI, 1.9-3.2) were the major predictors of hospital admission. Two children died, including one without a known pre-existing medical condition.

CONCLUSION

During 2020 and 2021, most SARS-CoV-2-positive children and adolescents who presented to participating hospitals could be managed as outpatients. Outcomes were generally good, including for those admitted to hospital.

COVID-19 related ICU admissions in paediatric and young adult patients in Australia: a national case series 2020-2022

Background

COVID-19 pandemic research efforts have focused on disease phenotypes in adults. A distinct spectrum of illness has been documented in paediatric populations. We aimed to review paediatric intensive care unit (ICU) admissions in Australia, across differing variant predominant phases of the pandemic.

Methods

Data reported to the Short PeRiod IncideNce sTudy of Severe Acute Respiratory Infection (SPRINT-SARI) Australia, across 49 ICUs from February 2020 to June 2022 were extracted. We defined 'child' as patients aged <12 years, 'adolescent' as patients aged 12-17 years, and 'young adult' as patients aged 18-25 years.

Findings

We identified 226 paediatric ICU admissions with COVID-19, representing 3.9% of ICU admissions across the study period. Comorbidity was present in 34.6% of children, 51.4% of adolescents, and 48.7% of young adults. The need for respiratory support was highest in young adults. While 28.3% of patients <18 years required invasive ventilation, in-hospital mortality in paediatric patients was 3.6%. During the Omicron period, there was an increase in the annualised incidence of age-specific COVID-19 ICU admissions per 100,000 population, albeit a decrease in the incidence per 1000 SARS-CoV-2 notifications.

Interpretation

This study demonstrated an appreciable burden of COVID-19 in paediatric patients. Adolescent patients presented phenotypically similar to young adults, however, illness severity was lower in younger cohorts. The Omicron phase of the pandemic demonstrated an increased age-specific population incidence of COVID-19 ICU admissions, albeit a reduced incidence when based on SARS-CoV-2 notifications.

Funding

SPRINT-SARI Australia is supported by the Department of Health, Commonwealth of Australia [Standing Deed SON60002733].

Understanding SARS-CoV-2 Delta and Omicron variant transmission and vaccine impact in schools and child-care settings in Australia; a population-based study

Background

Over 214 million students globally have been affected by school closures during the COVID-19 pandemic. To address knowledge gaps on transmission of SARS-CoV-2 delta (B.1.617.2) and omicron (B.1.1.529) variants in educational settings we examined virus transmission in schools and early childhood education and care settings (ECECs) in New South Wales (NSW), Australia in relation to mitigation measures, including COVID-19 vaccination.

Methods

Secondary transmission from children and adults with laboratory-confirmed SARS-CoV-2 infection who attended a school (n = 3170) or ECECs (n = 5800) while infectious was investigated over two periods: 1) June 16 to September 18, 2021 (delta outbreak), and; 2) October 18 to December 18, 2021 (delta and omicron; schools only). Close contacts of cases underwent 14 days quarantine and SARS-CoV-2 nucleic acid testing. Secondary attack rates (SARs) were calculated and compared with state-wide notification data, school attendance, and vaccination status.

Findings

1187 schools and 300 ECECs had students (n = 1349) or staff (n = 440) attend while infectious. Of 24,277 contacts investigated, most (91.8%; 22,297/24,277) were tested and 912 secondary cases identified. The secondary attack rate (SAR) was 5.9% in 139 ECECs and 3.5% in 312 schools. The risk of becoming a secondary case was higher in unvaccinated school staff (OR 4.7; 95% CI: 1.7–13.3), particularly ECEC staff (OR 9.0; 95% CI: 3.6–22.7) and unvaccinated school students than in vaccinated school staff. SARs were similar for delta (4.9%) and omicron BA.1 (4.1%) in the unvaccinated and higher compared with vaccinated contacts (0.9% and 3.4%, respectively). Increasing school attendance rates raised case incursions and secondary case numbers, but not community-wide infection rates.

Interpretation

Vaccination reduced SARS-CoV-2 transmission rates in schools, although less so for omicron than delta variants. Despite higher community-based transmission rates, in-school transmission remained low and stable with high attendance, suggesting that community restrictions, rather than school closures, best mitigated COVID-19 impacts.

Funding

10.13039/501100001207NSW Government Department of Health.

Paediatric admissions with SARS-CoV-2 during the Delta and Omicron waves: an Australian single-centre retrospective study

BACKGROUND

The clinical course of Australian children admitted to hospital with COVID-19 infection is not well understood, particularly over the Omicron period.

METHODS

This study describes paediatric admissions to a single tertiary paediatric institution through the Delta and Omicron variant waves. All children admitted from 1 June 2021 to 30 September 2022 with a diagnosis of COVID-19 infection were included for analysis.

RESULTS

117 patients were admitted during the Delta wave compared with 737 during the Omicron wave. The median length of stay was 3.3 days (IQR 1.7-6.75.1) during Delta, compared with 2.1 days (IQR 1.1-4.53.4) during Omicron (p<0.01). 83 patients (9.7%) required intensive care unit (ICU) admission, a greater proportion during Delta (20, 17.1%) than Omicron (63, 8.6%, p<0.01). Patients admitted to the ICU were less likely to have received a dose of COVID-19 vaccination prior to admission than patients admitted to the ward (8, 24.2% vs 154, 45.8%, p=0.028).

CONCLUSION

The Omicron wave resulted in an absolute increase in the number of children compared with Delta, but cases had lower severity, demonstrated by shorter length of stay and a smaller proportion of patients requiring intensive care. This is consistent with US and UK data describing a similar pattern.

Key lessons from the COVID-19 public health response in Australia

Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts. Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decision-making that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a 'standing threat', 10) regional and global solidarity is important. It should be acknowledged that we were unable to capture all relevant nuances and context specific differences. However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region.

The dilemma of improving rational antibiotic use in pediatric community-acquired pneumonia

Pneumonia is the number one cause of disease and deaths in children under five years old, outside the neonatal period, with the greatest number of cases reported from resource-limited settings. The etiology is variable, with not much information on the local etiology drug resistance profile in many countries. Recent studies suggest an increasing contribution from respiratory viruses, also in children with severe pneumonia, with an increased relative contribution in settings that have good vaccine coverage against common bacterial pathogens. Respiratory virus circulation was greatly reduced during highly restrictive measures to contain the spread of COVID-19 but rebounded once COVID-19 restrictions were relaxed. We conducted a comprehensive literature review of the disease burden, pathogens, case management and current available prevention of community acquired childhood pneumonia, with a focus on rational antibiotic use, since the treatment of respiratory infections is the leading cause of antibiotic use in children. Consistent application of revised World Health Organisation (WHO) guidance that children presenting with coryzal symptoms or wheeze can be managed without antibiotics in the absence of fever, will help to reduce unnecessary antibiotic use, as will increased availability and use of bedside inflammatory marker tests, such as C-reactive protein (CRP) in children with respiratory symptoms and fever.