Actualidad

Alerta sanitaria recibida desde Reino Unido y la Organización Mundial de la salud acerca de una hepatitis de causa desconocida que afecta fundamentalmente a niños menores de 10 años. Se han detectado casos en Inglaterra, Escocia e Irlanda, no relacionados entre ellos. Se han descartado las causas habituales por virus de la hepatitis y se investigan otro tipo de causas infecciosas, tóxicas o químicas. Alerta recibida desde la plataforma del Reglamento Sanitario Internacional (2005) de la Organización Mundial de la Salud:2022-04-10. OMS/IHR: UKOn 5 April 2022, the IHR National Focal Point for the United Kingdom notified WHO regarding 10 cases of severe acute hepatitis of unknown aetiology in previously healthy young children aged under 10 years in the central belt of Scotland. Ages ranged from 11 months to five years. Nine cases had onset of symptoms during March 2022 and one had an earlier onset in January 2022. Symptoms included jaundice, diarrhoea, vomiting and abdominal pain. All 10 cases were detected when hospitalised.

As of 8 April 2022, further investigations across the United Kingdom have identified a total of 74 cases fulfilling the case definition. The clinical syndrome in identified cases is of acute hepatitis with markedly elevated transaminases, often with jaundice, sometimes preceded by gastrointestinal symptoms, in children up to 10 years old. Some cases have required transfer to specialist children’s liver units and six children have undergone liver transplantation. Based on reports from the specialist units, no child has died. At least one epi-linked case has been detected.

Laboratory testing has excluded hepatitis A-E viruses in these children. SARS-CoV-2 and/or adenovirus have been detected in a number of the cases. The United Kingdom has recently observed an increase in adenovirus activity, which is co-circulating with SARS-CoV-2, though the role of these viruses in the pathogenesis is not yet clear. No other obvious epidemiological risk factors have been identified to date, including recent international travel. Overall, the aetiology of the current hepatitis cases is still considered unknown and remains under active investigation. Laboratory testing for additional infections, chemicals and toxins is underway for the identified cases.

Following notification though IHR/EWRS mechanisms, Ireland has reported three possible cases under investigation. At this stage, no other Member State has reported cases.

Working case definitions are as below. Patients presenting with the following criteria are being reviewed.·         Confirmed: A person presenting with an acute hepatitis (non-hepatitis viruses A-E) with aspartate transaminase (AST) or Alanine transaminase (ALT) over 500 U/L, who is 10 years old and under, since 1 January 2022.·         Possible: A person presenting with an acute hepatitis (non-hepatitis viruses A-E) with AST or ALT over 500 U/L, who is 11-16 years old, since 1 January 2022.·         Epi-linked: A person presenting with an acute hepatitis (non-hepatitis viruses A-E) of any age who is a close contact of a confirmed case since 1 January 2022. Public Health ActionsClinical and public health incident responses have been stood up across the United Kingdom to coordinate case finding with investigation into the cause of illness in these children. Further investigations by the United Kingdom authorities are ongoing to include more detailed exposure histories, toxicology testing, and additional virological/microbiological tests. Information is being shared with professional networks and specialist liver units. Guidance has been issued to support a thorough investigation of suspected cases.

WHO Risk AssessmentThe United Kingdom has observed a recent unexpected significant increase in cases of severe acute hepatitis of unknown aetiology in young children. Although the potential role of adenovirus and/or SARS-CoV-2 in the pathogenesis of these cases is one hypothesis, other infectious and non-infectious factors need to be fully investigated to properly assess and manage the risk.

As there is an on-going upward trend in the United Kingdom over the past month together with more extensive case searching, it is very likely that more cases will be detected before the aetiology has been found (either biological, chemical or other agent(s)) and corresponding appropriate control and prevention measures have been taken. Except for the few cases currently investigated by Ireland, the epidemiological situation outside the United Kingdom as of today remains unknown. WHO is closely monitoring the situation with other Member States together with the United Kingdom authorities and partners for cases with similar profiles.

WHO AdviceFurther work is required to identify cases both inside the United Kingdom and internationally. The priority is to determine the aetiology of these cases to guide further actions. Any epidemiological links between/among the cases might provide clues for tracking the source of illness. Temporal and geographical information of the cases, as well as their contacts should be reviewed for potential risk factors.

While some cases tested positive for SARS-CoV-2 and/or adenovirus, genetic characterisation of viruses should be undertaken to determine any potential associations with severe illness.   Member States are strongly encouraged to identify, investigate and report potential cases fitting the case definition above.

For more information, please see:·         The UK Health Security Agency (UKHSA), Increase in hepatitis (liver inflammation) cases in children under investigation, available at https://www.gov.uk/government/publications/hepatitis-increase-in-acute-cases-of-unknown-aetiology-in-children(link is external) (published on 8 April 2022)