The United States and several other countries are investigating an increase of hepatitis infections in young children.

Since November 2021, the Alabama Department of Public Health (ADPH) and Centers for Disease Control and Prevention are probing illnesses of nine children less than 10 years old.

These children had symptoms of a gastrointestinal illness and varying degrees of liver injury including failure. Two needed liver transplants. Further analyses revealed a possible association with Adenovirus 41. Adenoviruses do not usually cause hepatitis but it is a known rare complication. Hepatitis can also be spread through contaminated food and beverages.

The Alabama public health agency issued a Health alert Network (HAN) notification on Feb. 1, 2022. CDC is developing a national health advisory looking for clinically similar cases or associated with adenovirus infection in other states and is discussing the incident with international colleagues.

Scottish signal
The World Health Organization (WHO) said it was informed in early April of 10 cases of severe acute hepatitis in children younger than 10 in Scotland. Nine had onset of symptoms in March while the other fell ill in January. Symptoms included jaundice, diarrhea, vomiting and abdominal pain. All 10 patients’ hepatitis infections were detected when hospitalized.

The WHO warned it was “very likely” that more cases would be detected before the cause has been found and control and prevention measures taken.

Initial hypotheses in Scotland included either an infectious pathogen or a toxic exposure to food, drinks or toys popular with younger children. Toxicology analyses are ongoing although responses to the enhanced investigation questionnaire about food, drink and personal care habits have not yet identified any common exposures.

More detail about the cluster of cases of severe hepatitis of unknown origin in Scotland has been published in the journal Eurosurveillance.

At least 74 cases have been identified in the United Kingdom. Hepatitis viruses (A, B, C, D, and E) have been excluded after laboratory testing. Six children have had liver transplants but no deaths have been reported. None of the UK confirmed cases were vaccinated against COVID-19.

Dr. Jim McMenamin, from Public Health Scotland, said several lines of investigation are ongoing.

“In a number of cases, adenovirus and SARS-CoV2 have been detected, so these links are currently being investigated. Parents should contact their GP or other healthcare professional if they notice signs of jaundice in their child,” he said.

“This can be a yellow tinge in the whites of their eyes or on their skin. Other symptoms include dark urine, pale grey colored poo, itchy skin, muscle and joint pains, tiredness, feeling sick, a high temperature, loss of appetite and stomach pain. I would also encourage parents and others taking care of young children to be vigilant about hand and general hygiene.”

Adenovirus suspected
A group of viruses called adenoviruses may be behind the illnesses. However, other possible causes are also being investigated, including coronavirus (COVID-19) or environmental sources. Laboratory testing for additional infections, chemicals and toxins is underway.

There is no clear connection between reported cases and no obvious epidemiological risk factors have been identified. There is no known association with travel.

The European Centre for Disease Control and Prevention has also shared information about the illnesses to increase awareness among clinicians taking care of children, to see if there are any similar cases in other countries.

Five infections are being looked into in Ireland and three confirmed cases of acute hepatitis have been reported in children aged 22 months to 13-years-old in Spain. alerts have also been issued by health agencies in Belgium and Germany, but no cases have yet been noted in these countries.

“Mild hepatitis is very common in children following a range of viral infections, but what is being seen at the moment is quite different. Children are experiencing more severe inflammation, in a few cases leading the liver to fail and require transplantation,” said Graham Cooke, an infectious disease research professor at Imperial College London.

“Evidence of SARS-CoV-2 and another, unrelated, virus (adenovirus) has been found in some children, but both are common in the community at the moment, and so their presence might be coincidental.”

Adenoviruses are common viruses that typically cause a mild, self-limiting flu-like or gastrointestinal illness with symptoms including vomiting and diarrhea. They are commonly passed from person to person and by touching contaminated surfaces, as well as by coughing and sneezing.

The best way to minimize their spread is to practice good hand and respiratory hygiene and supervise thorough handwashing in younger children. Adenoviruses are often resistant to common disinfectants and can remain infectious for a long time on surfaces and objects.