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.

Ten Years of Medical Informatics and Standards Support for Clinical Research in an Infectious Diseases Network.

BACKGROUND: It is 30 years since evidence-based medicine became a great support for individual clinical expertise in daily practice and scientific research. Electronic systems can be used to achieve the goal of collecting data from heterogeneous datasets and to support multicenter clinical trials. The Ligurian Infectious Diseases Network (LIDN) is a web-based platform for data collection and reuse originating from a regional effort and involving many professionals from different fields. OBJECTIVES: The objective of this work is to present an integrated system of ad hoc interfaces and tools that we use to perform pseudonymous clinical data collection, both manually and automatically, to support clinical trials. METHODS: The project comprehends different scenarios of data collection systems, according to the degree of information technology of the involved centers. To be compliant with national regulations, the last developed connection is based on the standard Clinical Document Architecture Release 2 by Health Level 7 guidelines, interoperability is supported by the involvement of a terminology service. RESULTS: Since 2011, the LIDN platform has involved more than 8,000 patients from eight different hospitals, treated or under treatment for at least one infectious disease among human immunodeficiency virus (HIV), hepatitis C virus, severe acute respiratory syndrome coronavirus 2, and tuberculosis. Since 2013, systems for the automatic transfer of laboratory data have been updating patients' information for three centers, daily. Direct communication was set up between the LIDN architecture and three of the main national cohorts of HIV-infected patients. CONCLUSION: The LIDN was originally developed to support clinicians involved in the project in the management of data from HIV-infected patients through a web-based tool that could be easily used in primary-care units. Then, the developed system grew modularly to respond to the specific needs that arose over a time span of more than 10 years.

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.

Acute hepatitis A in international travellers: a GeoSentinel analysis, 2008-2020.

BACKGROUND: Non-immune international travellers are at risk of acquiring hepatitis A. Although hepatitis A vaccination is recommended for unvaccinated travellers to high or intermediate hepatitis A virus endemicity, compliance with this recommendation is not universal.The main objective was to describe the demographic and travel characteristics of international travellers infected with hepatitis A during travel. METHODS: Available data on travellers with confirmed (positive molecular test) or probable (symptomatic individuals with a single positive IgM test) hepatitis A diagnosed during and after travel from January 2008 to December 2020 were obtained from the GeoSentinel Surveillance Network database. We analysed demographic and travel characteristics of infected travellers. RESULTS: Among 254 travellers with hepatitis A (185 confirmed and 69 probable), the median age was 28 years (interquartile range: 19-40), 150 (59%) were male, and among 54 travellers with information available, 53 (98%) were unvaccinated. The most common reasons for travel included tourism (n = 120; 47%) and visiting friends or relatives (VFR; n = 72; 28%). About two-thirds of VFR travellers with hepatitis A (n = 50; 69%) were younger than 20 years old. Hepatitis A was acquired most frequently in South-Central Asia (n = 63; 25%) and sub-Saharan Africa (n = 61; 24%), but 16 travellers (6%) acquired hepatitis A in regions with low endemicity including Western Europe (n = 7; 3%), the Caribbean (n = 6; 2%) and North America (n = 3; 1%). Median duration from illness onset to GeoSentinel site presentation was ~7 days (interquartile range : 4-14 days). Among 88 travellers with information available, 59% were hospitalized. CONCLUSIONS: Despite availability of highly effective vaccines, travellers still acquire hepatitis A, even when traveling to low-endemicity destinations. Providing pre-departure hepatitis A vaccine to susceptible travellers is crucial to reducing travel-associated hepatitis A and should be offered to all travellers as part of the pre-travel consultation, regardless of destination.

Extensive activation, tissue trafficking, turnover and functional impairment of NK cells in COVID-19 patients at disease onset associates with subsequent disease severity.

The SARS-CoV-2 infection causes severe respiratory involvement (COVID-19) in 5-20% of patients through initial immune derangement, followed by intense cytokine production and vascular leakage. Evidence of immune involvement point to the participation of T, B, and NK cells in the lack of control of virus replication leading to COVID-19. NK cells contribute to early phases of virus control and to the regulation of adaptive responses. The precise mechanism of NK cell dysregulation is poorly understood, with little information on tissue margination or turnover. We investigated these aspects by multiparameter flow cytometry in a cohort of 28 patients hospitalized with early COVID-19. Relevant decreases in CD56brightCD16+/- NK subsets were detected, with a shift of circulating NK cells toward more mature CD56dimCD16+KIR+NKG2A+ and "memory" KIR+CD57+CD85j+ cells with increased inhibitory NKG2A and KIR molecules. Impaired cytotoxicity and IFN-γ production were associated with conserved expression of natural cytotoxicity receptors and perforin. Moreover, intense NK cell activation with increased HLA-DR and CD69 expression was associated with the circulation of CD69+CD103+ CXCR6+ tissue-resident NK cells and of CD34+DNAM-1brightCXCR4+ inflammatory precursors to mature functional NK cells. Severe disease trajectories were directly associated with the proportion of CD34+DNAM-1brightCXCR4+ precursors and inversely associated with the proportion of NKG2D+ and of CD103+ NK cells. Intense NK cell activation and trafficking to and from tissues occurs early in COVID-19, and is associated with subsequent disease progression, providing an insight into the mechanism of clinical deterioration. Strategies to positively manipulate tissue-resident NK cell responses may provide advantages to future therapeutic and vaccine approaches.

Bronchoalveolar lavage fluid characteristics and outcomes of invasively mechanically ventilated patients with COVID-19 pneumonia in Genoa, Italy.

BACKGROUND: The primary objective of the study is to describe the cellular characteristics of bronchoalveolar lavage fluid (BALF) of COVID-19 patients requiring invasive mechanical ventilation; the secondary outcome is to describe BALF findings between survivors vs non-survivors. MATERIALS AND METHODS: Patients positive for SARS-CoV-2 RT PCR, admitted to ICU between March and April 2020 were enrolled. At ICU admission, BALF were analyzed by flow cytometry. Univariate, multivariate and Spearman correlation analyses were performed. RESULTS: Sixty-four patients were enrolled, median age of 64 years (IQR 58-69). The majority cells in the BALF were neutrophils (70%, IQR 37.5-90.5) and macrophages (27%, IQR 7-49) while a minority were lymphocytes, 1%, TCD3+ 92% (IQR 82-95). The ICU mortality was 32.8%. Non-survivors had a significantly older age (p = 0.033) and peripheral lymphocytes (p = 0.012) were lower compared to the survivors. At multivariate analysis the percentage of macrophages in the BALF correlated with poor outcome (OR 1.336, CI95% 1.014-1.759, p = 0.039). CONCLUSIONS: In critically ill patients, BALF cellularity is mainly composed of neutrophils and macrophages. The macrophages percentage in the BALF at ICU admittance correlated with higher ICU mortality. The lack of lymphocytes in BALF could partly explain a reduced anti-viral response.

Prevalence and Clinical Significance of Persistent Viral Shedding in Hospitalized Adult Patients with SARS-CoV-2 Infection: A Prospective Observational Study.

BACKGROUND: The goal of this study was to investigate the prevalence and factors associated with persistent viral shedding (PVS) in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: This was a prospective observational study including all consecutive adults hospitalized with SARS-CoV-2 infection. When the first nasopharyngeal swab was positive for SARS-CoV-2 RNA (day 0), additional samples were obtained on days + 3, + 5, + 7 and then once every 7 days until virus detection was negative. PVS was defined as the duration of shedding of at least 21 days after diagnosis. The primary endpoint of this study was the prevalence of PVS. RESULTS: Data were obtained regarding 121 consecutive hospitalized patients with SARS-CoV-2 infection (median age 66 years, male sex 65.3%). Overall, the prevalence of PVS was 38% (46/121 patients). According to univariate analysis, factors associated with PVS were immunosuppression (6.7% vs 21.7%, p = 0.02), increased interleukin-6 (IL-6) levels (≥ 35 ng/ml) at the time of diagnosis (43.4% vs 67.3%, p = 0.02), time from onset of symptoms to diagnosis (median days 7.0 vs 3.5, p = 0.001), intensive care unit admission (22.7% vs 43.5%, p = 0.02), and need for invasive mechanical ventilation (20.0% vs 41.3%, p = 0.01). The multivariate analysis indicated that immunosuppression, increased IL-6 levels at the time of diagnosis, time from onset of symptoms to diagnosis, and need for mechanical ventilation were independent factors associated with PVS. CONCLUSIONS: PVS was detected in up to 38% of hospitalized patients with SARS-CoV-2 infection and was strongly associated with immunosuppression, increased IL-6 levels, and the need for mechanical ventilation.

Clinical characteristics, management and in-hospital mortality of patients with coronavirus disease 2019 in Genoa, Italy.

OBJECTIVES: To describe clinical characteristics, management and outcome of individuals with coronavirus disease 2019 (COVID-19); and to evaluate risk factors for all-cause in-hospital mortality. METHODS: This retrospective study from a University tertiary care hospital in northern Italy, included hospitalized adult patients with a diagnosis of COVID-19 between 25 February 2020 and 25 March 2020. RESULTS: Overall, 317 individuals were enrolled. Their median age was 71 years and 67.2% were male (213/317). The most common underlying diseases were hypertension (149/317; 47.0%), cardiovascular disease (63/317; 19.9%) and diabetes (49/317; 15.5%). Common symptoms at the time of COVID-19 diagnosis included fever (285/317; 89.9%), shortness of breath (167/317; 52.7%) and dry cough (156/317; 49.2%). An 'atypical' presentation including at least one among mental confusion, diarrhoea or nausea and vomiting was observed in 53/317 patients (16.7%). Hypokalaemia occurred in 25.8% (78/302) and 18.5% (56/303) had acute kidney injury. During hospitalization, 111/317 patients (35.0%) received non-invasive respiratory support, 65/317 (20.5%) were admitted to the intensive care unit (ICU) and 60/317 (18.5%) required invasive mechanical ventilation. All-cause in-hospital mortality, assessed in 275 patients, was 43.6% (120/275). On multivariable analysis, age (per-year increase OR 1.07; 95% CI 1.04-1.10; p < 0.001), cardiovascular disease (OR 2.58; 95% CI 1.07-6.25; p 0.03), and C-reactive protein levels (per-point increase OR 1.009; 95% CI 1.004-1.014; p 0.001) were independent risk factors for all-cause in-hospital mortality. CONCLUSIONS: COVID-19 mainly affected elderly patients with predisposing conditions and caused severe illness, frequently requiring non-invasive respiratory support or ICU admission. Despite supportive care, COVID-19 remains associated with a substantial risk of all-cause in-hospital mortality.

Tocilizumab and steroid treatment in patients with COVID-19 pneumonia.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) can lead to respiratory failure due to severe immune response. Treatment targeting this immune response might be beneficial but there is limited evidence on its efficacy. The aim of this study was to determine if early treatment of patients with COVID-19 pneumonia with tocilizumab and/or steroids was associated with better outcome. METHODS: This observational single-center study included patients with COVID-19 pneumonia who were not intubated and received either standard of care (SOC, controls) or SOC plus early (within 3 days from hospital admission) anti-inflammatory treatment. SOC consisted of hydroxychloroquine 400mg bid plus, in those admitted before March 24th, also darunavir/ritonavir. Anti-inflammatory treatment consisted of either tocilizumab (8mg/kg intravenously or 162mg subcutaneously) or methylprednisolone 1 mg/kg for 5 days or both. Failure was defined as intubation or death, and the endpoints were failure-free survival (primary endpoint) and overall survival (secondary) at day 30. Difference between the groups was estimated as Hazard Ratio by a propensity score weighted Cox regression analysis (HROW). RESULTS: Overall, 196 adults were included in the analyses. They were mainly male (67.4%), with comorbidities (78.1%) and severe COVID-19 pneumonia (83.7%). Median age was 67.9 years (range, 30-100) and median PaO2/FiO2 200 mmHg (IQR 133-289). Among them, 130 received early anti-inflammatory treatment with: tocilizumab (n = 29, 22.3%), methylprednisolone (n = 45, 34.6%), or both (n = 56, 43.1%). The adjusted failure-free survival among tocilizumab/methylprednisolone/SOC treated patients vs. SOC was 80.8% (95%CI, 72.8-86.7) vs. 64.1% (95%CI, 51.3-74.0), HROW 0.48, 95%CI, 0.23-0.99; p = 0.049. The overall survival among tocilizumab/methylprednisolone/SOC patients vs. SOC was 85.9% (95%CI, 80.7-92.6) vs. 71.9% (95%CI, 46-73), HROW 0.41, 95%CI: 0.19-0.89, p = 0.025. CONCLUSION: Early adjunctive treatment with tocilizumab, methylprednisolone or both may improve outcomes in non-intubated patients with COVID-19 pneumonia.