Investigation into cases of hepatitis of unknown aetiology among young children, Scotland, 1 January 2022 to 12 April 2022

Revisiting the overlooked role of recycled sewage water in high-income countries in adenoviral outbreaks such as the “2022 pediatric hepatitis’ outbreak”

Background

On the 5th of April 2022, cases of adenovirus-induced hepatitis were reported in Scotland and then reached multiple parts of the world. While adenovirus normally presents with diarrhea, vomiting, and fever, these novel cases also resulted in the development of fulminant hepatitis in non-immunocompromised cases.

Main body

The responsible pathogen “Adenovirus 41” is an enterovirus. Enteroviruses are spread by the fecal-oral route and are resistant to drying. As such, they predominate in sewage water. Hepatitis is normally restricted to poorer countries, yet this new wave seems to be confined to mostly high-income countries in Europe and the USA. These countries treat and recycle a higher percentage of sewage water. We also propose that the fulminant nature of this strain could be due to either a cross-species mutation or the general decrease in trained immunity post-COVID-19 lockdown.

Short conclusion

Evidence strongly suggests that the link between these new hepatitis cases is recycled sewage water. This should warrant further investigations on the origin of this outbreak by re-visiting the role of recycled sewage water in causing such outbreak.

Potential protective benefits of Schisandrin B against severe acute hepatitis in children during the COVID-19 pandemic based on a network pharmacology analysis

Aims: Reports of hepatitis in children during the coronavirus disease 2019 (COVID-19) pandemic garnered worldwide attention. The most probable culprits are adenovirus and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). At present, the optimal symptomatic treatment consists of a combination of anti-COVID-19 and hepatitis symptom alleviators. Schisandrin B (SchB) has been known to have liver-protective properties for a long time, whereas anti-COVID-19 properties only recently have been discovered. In the case of COVID-19 with hepatitis of unknown origin, we used network pharmacology to explore the symptomatic therapy and protective effects of SchB. Main methods: The most probable protein targets of SchB were predicted in the SwissTargetPrediction database. The GeneCards, National Center for Biotechnology Information, and Online Mendelian Inheritance in Man databases were used to compile information on the diseases hepatitis, adenovirus, and SARS-CoV-2. Following the use of a Venn diagram viewer to identify intersection genes, we constructed a protein-protein interaction network and identified the core genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment, as well as molecular docking, were employed to highlight the mechanisms of SchB on hepatitis. Key findings: SchB contains 27 targets on adenovirus_hepatitis and 16 targets on SARS-CoV-2_hepatitis, with 12 shared genes. Both target populations clustered in viral infection and cancer pathways, as well as in processes such as kinase activity phosphatase, cell adhesion, and ATPase binding. These genes might be closely related to liver damage and membrane binding from adenovirus or SARS-CoV-2 infections. In addition, epidermal growth factor receptor, HSP90AA1, and MAPK1 were among the top five targets of both SchB SARS-CoV-2 hepatitis and SchB adenovirus hepatitis. Significance: SchB may target common protective targets and mechanisms against acute hepatitis caused by adenovirus or by SARS-CoV-2 in children during the COVID-19 pandemic. These findings indicate SchB's potential as a treatment for hepatitis of unknown origin.

Hepatitis of unknown etiology in children: What we know and what we can do?

Recently, acute hepatitis of unknown etiology in children has gained great concern since March 2022. The disease was first reported by Public Health Scotland. Cases increased rapidly and are now reported in 33 countries worldwide. All cases are predominantly aged under 5 years old. Most patients presented with jaundice, and remarkably, some cases progress to acute liver failure. Until now, the etiology is not fully elucidated, and the investigations are ongoing. Adenovirus infection seems to be an important factor. Several hypotheses on the etiology have been proposed. This review aims to summarize current research progress and put forward some suggestions.

Hepatitis of unknown aetiology in children - epidemiological overview of cases reported in Europe, 1 January to 16 June 2022

Following the report of an excess in paediatric cases of severe acute hepatitis of unknown aetiology by the United Kingdom (UK) on 5 April 2022, 427 cases were reported from 20 countries in the World Health Organization European Region to the European Surveillance System TESSy from 1 January 2022 to 16 June 2022. Here, we analysed demographic, epidemiological, clinical and microbiological data available in TESSy. Of the reported cases, 77.3% were 5 years or younger and 53.5% had a positive test for adenovirus, 10.4% had a positive RT-PCR for SARS-CoV-2 and 10.3% were coinfected with both pathogens. Cases with adenovirus infections were significantly more likely to be admitted to intensive care or high-dependency units (OR = 2.11; 95% CI: 1.18–3.74) and transplanted (OR = 3.36; 95% CI: 1.19–9.55) than cases with a negative test result for adenovirus, but this was no longer observed when looking at this association separately between the UK and other countries. Aetiological studies are needed to ascertain if adenovirus plays a role in this possible emergence of hepatitis cases in children and, if confirmed, the mechanisms that could be involved.

Serum hepatic biomarkers in women with obstetric cholestasis and a concurrent SARS-CoV-2 infection

Aim

The aim of the study was to evaluate the association between SARS‐CoV‐2 infection and serum hepatic biomarker levels among women with obstetric cholestasis.

Methods

In this prospective study, we recruited all pregnant women admitted in our hospital with obstetric cholestasis. Among those with a concurrent SARS‐CoV‐2 infection, we evaluated the following serum hepatic biomarkers: aspartate aminotransferase (AST), alanine aminotransferase (ALT), and biliar acids (BA).

Results

Among the 88 women enrolled in the study, 20 presented with a SARS‐CoV‐2 infection while 68 were negative. SARS‐CoV‐2 infected women were younger (mean age 30.5 ± 5.7 vs. 34.3 ± 5.4; p < 0.01) and in a greater percentage of non‐Caucasian ethnicity when compared to noninfected women (60.0% vs. 17.6%; p < 0.01). Regarding levels of hepatic biomarkers, they showed higher levels of AST (111.5 ± 134.1 vs. 37.3 ± 43.4 UI/L; p = 0.02), ALT (132.2 ± 115.7 vs. 50.5 ± 73.173.1 UI/L; p < 0.01), and BA (41.4 ± 46.8 vs. 18.4 ± 13.4 μmol/L; p = 0.04) compared to noninfected patients. No significant differences in maternal or fetal outcomes were found between infected and noninfected women.

Conclusion

SARS‐CoV‐2 infection was associated with higher levels of liver enzymes in patients with obstetric cholestasis. This could be the result of a possible hepatic involvement in patients with SARS‐CoV‐2 infection.

Acute severe hepatitis of unknown etiology in children: A mini-review

The emergence of acute, severe non hepA-E hepatitis of unknown etiology (ASHUE) has attracted global concern owing to the very young age of the patients and its unknown etiology. Although this condition has been linked to several possible causes, including viral infection, drugs and/or toxin exposure, the exact cause remains unknown; this makes treatment recommendation very difficult. In this review, we summarize recent updates on the clinical manifestations, complemented with laboratory results, case numbers with the global distribution and other epidemiological characteristics, and the possible etiologies. We also provide the proposed actions that could be undertaken to control and prevent further spread of this hepatitis. Since many etiological and pathological aspects of the acute non hepA-E hepatitis remain unclear, further research is needed to minimize the severe impact of this disease.

Severe acute hepatitis of unknown aetiology in children-what is known?

The ongoing investigations into clusters of children affected by severe acute hepatitis of unknown aetiology have put our global capacity for a coordinated, effective response to the test. The global health community have rapidly convened to share data and inform the response. In the UK, where most cases were initially identified, a coordinated public health and clinical research response was rapidly initiated. Since then, cases have been reported from other countries, predominantly from higher-income countries. While agencies are keeping an open mind to the cause, the working hypothesis and case notifications raise important questions about our capacity to detect emerging cases in lower-resourced settings with a recognised lack of access to diagnostics even for commonly circulating viruses such as hepatitis A. The limited capability to generate integrated global pathogen surveillance data is a challenge for the outbreak investigations, highlighting an urgent need to strengthen access to diagnostics, with a focus on lower-resourced settings, to improve the capacity to detect emerging diseases to inform care and to improve outcomes and outbreak control.

Pediatric Acute Severe Hepatitis of Unknown Origin: What is New?

Globally, there are emerging cases of acute severe hepatitis of unknown origin in children. These cases have gathered increasing attention, owing to the development of acute liver failure in some cases that resulted in liver transplantation. This review briefly summarizes the outbreak and diagnostic criteria of the disease. We further discuss the possible causes and related mechanisms underlying its occurrence and progression, and analyze the challenges in management. Finally, this review emphasizes patient management in clinical settings and a combination of efforts to unmask the disease.

Acute Hepatitis of Unknown Origin in Children: Early Observations from the 2022 Outbreak

Recent reports of acute hepatitis of unknown origin in previously healthy children have been increasing worldwide. The main characteristics of the affected children were jaundice and gastrointestinal symptoms. Their serum aminotransaminase levels were above 500 IU/L, with negative tests for hepatitis viruses A-E. By 31 May 2022, the outbreak had affected over 800 children under the age of 16 years in more than 40 countries, resulting in acute liver failure in approximately 10%, including at least 21 deaths and 38 patients requiring liver transplantation. There was still no confirmed cause or causes, although there were several different working hypotheses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), adenovirus serotype 41, or SARS-CoV-2 superantigen-mediated immune cell activation. Here, we review early observations of the 2022 outbreak which may inform diagnosis, treatment, and prevention in the context of an overlapping COVID-19 pandemic.

Suspected Adenovirus Causing an Emerging HEPATITIS among Children below 10 Years: A Review

In October 2021, a case of acute hepatic failure without any known cause was identified in the United States of America. Upon further investigation, other children aged 1–6 years were reported to have the same liver failure, and some of them were positive for adenovirus 41 type F. On 21 April 2022, the Centers for Disease Control and Prevention (CDC) released an alert after 74 cases were identified in United Kingdom (UK) between 5 and 8 April in children below 10 years of age, some of whom were also found to be positive for SARS-CoV-2. All the patients showed symptoms such as vomiting, diarrhea, jaundice, and abdominal pain. The patients’ liver enzymes were remarkably increased. A total of 650 cases had been reported from 33 countries as of 27 May 2022, among which 222 cases were reported in the UK alone. No connection with SARS-CoV-2 or its vaccine has been found so far. However, the suspected cause is adenovirus, including its genomic variations, because its pathogenesis and laboratory investigations have been positively linked. Until further evidence emerges, hygiene precautions could be helpful to prevent its spread.

Trends in Acute Hepatitis of Unspecified Etiology and Adenovirus Stool Testing Results in Children - United States, 2017-2022

In November 2021, CDC was notified of a cluster of previously healthy children with hepatitis of unknown etiology evaluated at a single U.S. hospital (1). On April 21, 2022, following an investigation of this cluster and reports of similar cases in Europe (2,3), a health advisory* was issued requesting U.S. providers to report pediatric cases^† of hepatitis of unknown etiology to public health authorities. In the United States and Europe, many of these patients have also received positive adenovirus test results (1,3). Typed specimens have indicated adenovirus type 41, which typically causes gastroenteritis (1,3). Although adenovirus hepatitis has been reported in immunocompromised persons, adenovirus is not a recognized cause of hepatitis in healthy children (4). Because neither acute hepatitis of unknown etiology nor adenovirus type 41 is reportable in the United States, it is unclear whether either has recently increased above historical levels. Data from four sources were analyzed to assess trends in hepatitis-associated emergency department (ED) visits and hospitalizations, liver transplants, and adenovirus stool testing results among children in the United States. Because of potential changes in health care-seeking behavior during 2020-2021, data from October 2021-March 2022 were compared with a pre-COVID-19 pandemic baseline. These data do not suggest an increase in pediatric hepatitis or adenovirus types 40/41 above baseline levels. Pediatric hepatitis is rare, and the relatively low weekly and monthly counts of associated outcomes limit the ability to interpret small changes in incidence. Ongoing assessment of trends, in addition to enhanced epidemiologic investigations, will help contextualize reported cases of acute hepatitis of unknown etiology in U.S. children.

[The investigation on the acute, severe hepatitis of unknown origin in children]

In April 2022, the United Kingdom notified the World Health Organization (WHO) of an unexpected increase of acute hepatitis of unknown origin in children. Subsequent investigations have found more than 400 cases in more than 20 countries and regions around the world. Although the potential role of adenovirus type 41 in the pathogenesis of these cases is one hypothesis, but it is probably not the only pathogenic factor, and other infectious and non-infectious causes cannot be completely ruled out. For hepatitis caused by non-hepatitis A, B, C, D and E viruses, there is a lack of systematic monitoring and research, and many unknowns still exist. According to the current etiology speculation and epidemiological characteristics of adenovirus in China, cases of acute hepatitis with unknown origin may be found in China in the future. There is also a risk of imported cases. This article systematically sorts out the reports and studies on child acute hepatitis of unknown origin, hoping to attract the attention of pediatric clinicians in China, raise awareness and vigilance, and calmly prepare for possible abnormal situations.

Hepatitis of Unknown Origin and Etiology (Acute Non HepA-E Hepatitis) among Children in 2021/2022: Review of the Current Findings

Several clusters and individual cases of acute hepatitis have been reported in the US, Europe and recently in Asia and Central America since October 2021. A laboratory investigation of the common viral hepatitis agents (HAV, HBV, HCV, HDV and HEV) yielded negative results prompting the use of the term “acute non HepA-E hepatitis” to describe this condition. The cases were characterized by the manifestations of acute hepatitis (abdominal pain, vomiting, diarrhea, jaundice and very high levels of liver enzymes) affecting children with a median age of 3–4 years. The exact underlying etiology has not been revealed yet; however, a leading hypothesis is that an infectious agent is the culprit, underlying cause or a risk factor for acute non HepA-E hepatitis occurrence. So far, laboratory testing has shown the presence of the group F human adenovirus serotype 41 (HAdV-F41) in about three-fourths of the investigated cases. As of 13 May 2022, more than 450 cases were reported worldwide, the majority of which were in the UK (n = 176), the US (n = 109), 13 European countries (at least 103 cases) and in Argentina, Brazil, Canada, Costa Rica, Indonesia, Israel, Japan, Palestine, Panama, Singapore and South Korea. Vigilant surveillance and epidemiologic investigations to identify further cases are warranted to delineate the features of this emergent public health issue. The possible role of environmental and toxic agents including foodborne toxins should also be considered. Specific guidelines for identification of further cases are necessary, particularly in low-income settings where testing for adenoviruses is not considered routinely. A genetic analysis of HAdV-F41 isolates is recommended to assess the potential changes in the virus genome with subsequent possible altered virus behavior. Immunopathogenesis is another possibility that should be evaluated considering the lack of viral structures in liver biopsies of the affected children in the US.

Human Identical Sequences, hyaluronan, and hymecromone ─ the new mechanism and management of COVID-19

COVID-19 caused by SARS-CoV-2 has created formidable damage to public health and market economy. Currently, SARS-CoV-2 variants has exacerbated the transmission from person-to-person. Even after a great deal of investigation on COVID-19, SARS-CoV-2 is still rampaging globally, emphasizing the urgent need to reformulate effective prevention and treatment strategies. Here, we review the latest research progress of COVID-19 and provide distinct perspectives on the mechanism and management of COVID-19. Specially, we highlight the significance of Human Identical Sequences (HIS), hyaluronan, and hymecromone ("Three-H") for the understanding and intervention of COVID-19. Firstly, HIS activate inflammation-related genes to influence COVID-19 progress through NamiRNA-Enhancer network. Accumulation of hyaluronan induced by HIS-mediated HAS2 upregulation is a substantial basis for clinical manifestations of COVID-19, especially in lymphocytopenia and pulmonary ground-glass opacity. Secondly, detection of plasma hyaluronan can be effective for evaluating the progression and severity of COVID-19. Thirdly, spike glycoprotein of SARS-CoV-2 may bind to hyaluronan and further serve as an allergen to stimulate allergic reaction, causing sudden adverse effects after vaccination or the aggravation of COVID-19. Finally, antisense oligonucleotides of HIS or inhibitors of hyaluronan synthesis (hymecromone) or antiallergic agents could be promising therapeutic agents for COVID-19. Collectively, Three-H could hold the key to understand the pathogenic mechanism and create effective therapeutic strategies for COVID-19.

The recent outbreak of acute and severe hepatitis of unknown etiology in children: a possible role of human adenovirus infection?

The Public Health Scotland (PHS) was notified at the end of March 2022 that five children aged 3-5 years had presented to the Royal Hospital for Children in Glasgow with acute hepatitis of unknown etiology within a three-week period.Keywords This article is protected by copyright. All rights reserved.

Case numbers of acute hepatitis of unknown aetiology among children in 24 countries up to 18 April 2022 compared to the previous 5 years

An increase of acute hepatitis of unknown aetiology has been reported among children in multiple countries worldwide. With a rapid online survey among hospitals in and outside of Europe, we describe case numbers recorded from 1 January to 18 April 2022 vs the previous 5 years. Of 24 countries that responded, we identified 5/17 European and 1/7 non-European countries with an elevation in probable cases of unexplained acute hepatitis, and severe cases were elevated in five European countries.

Acute, Severe Hepatitis of Unknown Origin: Should We Really Be Afraid of Another Obscure Enemy of Our Children?

On 31 March 2022, Public Health Scotland was alerted to five children aged 3-5 years, presenting to the Glasgow children's hospital with severe hepatitis of unknown etiology within a 3-week period [...].

Acute severe hepatitis outbreak in children: A perfect storm. What do we know, and what questions remain?

During the first half of 2022, the World Health Organization reported an outbreak of acute severe hepatitis of unknown aetiology (AS-Hep-UA) in children, following initial alerts from the United Kingdom (UK) where a cluster of cases was first observed in previously well children aged <6 years. Sporadic cases were then reported across Europe and worldwide, although in most countries incidence did not increase above the expected baseline. There were no consistent epidemiological links between cases, and microbiological investigations ruled out known infectious causes of hepatitis. In this review, we explore the evidence for the role of viral infection, superimposed on a specific host genetic background, as a trigger for liver pathology. This hypothesis is based on a high prevalence of Human Adenovirus (HAdV) 41F in affected children, together with metagenomic evidence of adeno-associated virus (Adeno-associated viruses)-2, which is a putative trigger for an immune-mediated liver injury. Roles for superantigen-mediated pathology have also been explored, with a focus on the potential contribution of SARS-CoV-2 infection. Affected children also had a high frequency of the MHC allele HLA-DRB1*04:01, supporting an immunological predisposition, and may have been vulnerable to viral coinfections due to disruption in normal patterns of exposure and immunity as a result of population lockdowns during the COVID-19 pandemic. We discuss areas of ongoing uncertainty, and highlight the need for ongoing scrutiny to inform clinical and public health interventions for this outbreak and for others that may evolve in future.

Human adenovirus (HAdV) infection in children with acute respiratory tract infections in Guangzhou, China, 2010-2021: a molecular epidemiology study

BACKGROUND

Human adenovirus (HAdV) infection can cause a variety of diseases. It is a major pathogen of pediatric acute respiratory tract infections (ARIs) and can be life-threatening in younger children. We described the epidemiology and subtypes shifting of HAdV among children with ARI in Guangzhou, China.

METHODS

We conducted a retrospective study of 161,079 children diagnosed with acute respiratory illness at the Guangzhou Women and Children's Medical Center between 2010 and 2021. HAdV specimens were detected by real-time PCR and the hexon gene was used for phylogenetic analysis.

RESULTS

Before the COVID-19 outbreak in Guangzhou, the annual frequency of adenovirus infection detected during this period ranged from 3.92% to 13.58%, with an epidemic peak every four to five years. HAdV demonstrated a clear seasonal distribution, with the lowest positivity in March and peaking during summer (July or August) every year. A significant increase in HAdV cases was recorded for 2018 and 2019, which coincided with a shift in the dominant HAdV subtype from HAdV-3 to HAdV-7. The latter was associated with a more severe disease compared to HAdV-3. The average mortality proportion for children infected with HAdV from 2016 to 2019 was 0.38% but increased to 20% in severe cases. After COVID-19 emerged, HAdV cases dropped to 2.68%, suggesting that non-pharmaceutical interventions probably reduced the transmission of HAdV in the community.

CONCLUSION

Our study provides the foundation for the understanding of the epidemiology of HAdV and its associated risks in children in Southern China.

Diagnosis, treatment, and prevention of severe acute hepatitis of unknown etiology in children

BACKGROUND

Severe acute hepatitis of unknown etiology in children has recently exhibited a global trend of concentrated occurrence. This review aimed to summarize the current available information regarding the outbreak of severe acute hepatitis and introduce our hospital's previous experiences with the diagnosis and treatment of severe acute hepatitis for reference.

DATA SOURCES

Websites including the UK Health Security Agency, European Centre for Disease Prevention and Control, CDC, WHO, and databases including PubMed/Medline, Cochrane Library, Embase and Web of Science were searched for articles on severe acute hepatitis in children.

RESULTS

As of May 26, 2022, a total of 650 cases have been reported in 33 countries; at least 38 (6%) children required liver transplantation, and nine (1%) died. Cases are predominantly aged between 3 and 5 years old, and there are no epidemiological links among them. The common manifestations are jaundice, vomiting and pale stools. Adenovirus tested positive in most cases, and SARS-CoV-2 and other viruses were detected in a few cases, but virus particles were not found in liver tissue. Adenovirus immunohistochemistry showed immunoreactivity in the intrasinusoidal lumen from some liver samples. The hierarchical treatment includes symptomatic and supportive therapy, management of coagulation disorders and hepatic encephalopathy, artificial liver support, and liver transplantation (approximately 6%-10% of cases require liver transplant).

CONCLUSIONS

The etiology of this severe acute hepatitis in children is not clear. The clinical features are severe acute hepatitis with significantly elevated liver enzymes. Clinicians need to be alert to children with hepatitis.