This spring, global health advisories have been issued regarding an alarming – and as-yet unexplained – uptick of hepatitis in children. Currently, over 200 cases have been reported worldwide, a relatively small amount that nonetheless belies a considerable toll, including several deaths and the need for liver transplantation in a number of patients. The long-term implications are not yet known. Global health officials are working hard to determine a cause, with many focusing on the underlying cases of adenovirus that several patients have presented with.
To understand more, this news organization reached out to frequent contributor William F. Balistreri, MD, a specialist in pediatric gastroenterology and hepatology at Cincinnati Children’s Hospital Medical Center, where to date they have treated at least six cases of hepatitis in otherwise healthy young children, with one requiring a liver transplant. Dr. Balistreri discussed how the outbreak has developed to date, his advice to hepatologists and pediatricians, and where we stand now in this fast-evolving crisis.
Tracing the outbreak in the United States
How has this outbreak played out thus far in the United States, and what have we learned from that?
Sporadic reports of cases in multiple states are appearing. On April 21, 2022, a health alert was issued by the Centers for Disease Control and Prevention, recommending testing for adenovirus in children with acute hepatitis of an unknown etiology.
Baker and colleagues recently described five children with severe hepatitis and adenovirus viremia who were admitted to a children’s hospital in Birmingham, Ala., between October and November 2021. In collaboration with local and state officials, the CDC reviewed clinical records in order to identify patients with hepatitis and concomitant adenovirus infection, confirmed by polymerase chain reaction (PCR).
By February 2022, a total of nine children were identified. There was no epidemiologic linkage among these nine patients; all were well and immunocompetent. The prodromal features were somewhat similar: upper respiratory infection, vomiting, diarrhea, and jaundice. All children had markedly elevated aminotransferase levels and variably elevated total bilirubin levels. Extensive workup for other causes of acute liver injury (for example, other viruses, toxins/drugs, metabolic and autoimmune diseases) was unrevealing.
Specifically, none had documented SARS-CoV-2 infection. However, in all nine children, adenovirus was detected in whole blood samples. In the six children who underwent liver biopsy, there was nonspecific hepatitis, without inclusions or immunohistochemical detection of viral agents, including adenovirus. In three patients, the liver injury progressed, and despite the administration of antiviral agents, two underwent liver transplantation.
Baker and colleagues also suggested that measurement of adenovirus titers in whole blood (rather than plasma) may be more sensitive.
The CDC has recommended monitoring and surveillance in order to more fully understand the nature of the illness.
European and global cases
What has been the experience with this in Europe and elsewhere globally?
In mid-to-late 2021, several cases of acute hepatitis of unknown nature in children were identified in Europe. Public health officials in the United Kingdom investigated the high number of cases seen in children from England, Scotland, and Wales. They noted approximately 60 cases in England, mostly in children aged 2-5 years.
Marsh and colleagues reported a cluster of cases of severe hepatitis of unknown origin in Scotland affecting children aged 3-5 years. In Scotland, admitted cases were routinely tested for SARS-CoV-2. Of the 13 cases, five had a recent positive test. They discussed the possibility of increased severity of disease following infection with Omicron BA.2 (the dominant SARS-CoV-2 virus circulating in Scotland at that time) or infection by an uncharacterized SARS-CoV-2 variant. None of the children had been vaccinated for SARS-CoV-2.
On April 15, 2022, the World Health Organization Disease Outbreak News published a report of acute hepatitis of unknown etiology occurring in Great Britain and Northern Ireland. By April 21, 2022, 169 cases of acute hepatitis of unknown origin in children younger than 16 years had been reported from 11 countries in the WHO European region and 1 country in the WHO region of the Americas. Approximately 10% required a liver transplantation and at least one death was reported.