Paediatric acute hepatitis of unknown aetiology: a national investigation and adenoviraemia case-control study in the UK.

BACKGROUND: An increase in acute severe hepatitis of unknown aetiology in previously healthy children in the UK in March, 2022, triggered global case-finding. We aimed to describe UK epidemiological investigations of cases and their possible causes. METHODS: We actively surveilled unexplained paediatric acute hepatitis (transaminase >500 international units per litre) in children younger than 16 years presenting since Jan 1, 2022, through notifications from paediatricians, microbiologists, and paediatric liver units; we collected demographic, clinical, and exposure information. Then, we did a case-control study to investigate the association between adenoviraemia and other viruses and case-status using multivariable Firth penalised logistic regression. Cases aged 1-10 years and tested for adenovirus were included and compared with controls (ie, children admitted to hospital with an acute non-hepatitis illness who had residual blood samples collected between Jan 1 and May 28, 2022, and without known laboratory-confirmed diagnosis or previous adenovirus testing). Controls were frequency-matched on sex, age band, sample months, and nation or supra-region with randomised selection. We explored temporal associations between frequency of circulating viruses identified through routine laboratory pathogen surveillance and occurrence of cases by linear regression. SARS-CoV-2 seropositivity of cases was examined against residual serum from age-matched clinical comparison groups. FINDINGS: Between Jan 1 and July 4, 2022, 274 cases were identified (median age 3 years [IQR 2-5]). 131 (48%) participants were male, 142 (52%) were female, and one (<1%) participant had sex data unknown. Jaundice (195 [83%] of 235) and gastrointestinal symptoms (202 [91%] of 222) were common. 15 (5%) children required liver transplantation and none died. Adenovirus was detected in 172 (68%) of 252 participants tested, regardless of sample type; 137 (63%) of 218 samples were positive for adenovirus in the blood. For cases that were successfully genotyped, 58 (81%) of 72 had Ad41F, and 57 were identified as positive via blood samples (six of these were among participants who had undergone a transplant). In the case-control analysis, adenoviraemia was associated with hepatitis case-status (adjusted OR 37·4 [95% CI 15·5-90·3]). Increases in the detection of adenovirus from faecal samples, but not other infectious agents, in routine laboratory pathogen surveillance correlated with hepatitis cases 4 weeks later, which independently suggested an association (ß 0·06 [95% CI 0·02-0·11]). No association was identified for SARS-CoV-2 antibody seropositivity. INTERPRETATION: We observed an association between adenovirus 41F viraemia and paediatric acute hepatitis. These results can inform diagnostic testing recommendations, clinical management, and exploratory in vitro or clinical studies of paediatric acute hepatitis of unknown aetiology. The role of potential co-factors, including other viruses and host susceptibility, requires further investigation. FUNDING: None.

Monkeypox: A current emergency global health threat.

Monkeypox (MPXV) is an emerging zoonotic disease carrying a global health threat. Using a multi-disciplinary approach, we review the current MPXV virus infection outbreak including virology, prevention, clinical presentation, and disaster management. MPXV is caused by a double-stranded deoxyribonucleic acid virus. Despite its clinical similarities with smallpox, it is less severe with low mortality. Human-to-human transmission occurs through prolonged direct or close contact, or through blood, body fluids, or mucosal lesions. Risk groups include frontline health workers who care for MPXV patients, household members of an infected patient, and men who have sex with men. Skin lesions are usually, but not always, at the same stage. They may affect the face followed by the distal extremities with fewer lesions on the trunk (centrifugal distribution). Lesions may involve the mouth, genitalia, conjunctiva, and rectum. The majority of cases are mild. Nevertheless, the disease may have long-term effects on the skin, the neurological system, and the eye. Vaccination against MPXV is available but meanwhile should be limited to those who are at high risk. Those vaccinated against smallpox (usually older than 40 years) might be immune against MPXV. Infectious diseases are without borders. If proper action is not taken, there is considerable risk that MPXV will be entrenched worldwide. Our world has a delicate balance between animals, environment, and humans reflecting the need for a "one globe, one health approach" to address this risk. Following the principles of disaster management and using the lessons we have learned from the COVID-19 pandemic will reduce the impact of the MPXV outbreak.

Influenza B outbreak at an adult cystic fibrosis centre - Clinical impact and factors influencing spread.

INTRODUCTION: An outbreak of Influenza B occurred at a large United Kingdom (UK) regional adult cystic fibrosis (CF) centre in May 2016. This was late in the UK 2015-2016 influenza season and occurred on a specialist ward with strict infection control procedures. This study investigates the spread of influenza, clinical consequences and potential contributing factors. METHODS: Patient records, clinical status and pulmonary function data were reviewed for all inpatients during this period. Respiratory viral PCR results, influenza vaccination status of patients and staff, and environmental factors were also recorded. Affected patients were prospectively monitored for the following three months. RESULTS: 10 of 21 inpatients developed influenza B between 5th and 12th May 2016, an attack rate of 48%. All those characterised were confirmed as the same strain of influenza B/Victoria-lineage. Influenza infection resulted in a mean FEV1 reduction of 10.5% (SD 11.3, p = 0.012), which persisted at 3 months post infection (p = 0.003). Nine of the affected cases rooms were in close proximity on the ward while patients in the two isolation rooms with enhanced ventilation did not become infected. Ventilation measurements in affected rooms ranged from 1.75 to 2.10 air changes/hour, below national recommendations. Seventy percent of affected inpatients had received the 2015/16 trivalent seasonal influenza vaccine, which did not contain a B/Victoria-lineage influenza B virus. CONCLUSION: This influenza B outbreak in CF adults had a high attack rate and a significant clinical impact. Room ventilation and a limited protection from the seasonal influenza vaccine were possible contributory factors.