#16,697
For more than a week (see here, here, and here) we've been following the UK's investigation into an unusual outbreak of hepatitis among young children; one - as yet - without a known cause.
The usual suspects - Hepatitis A-E viruses - have all tested negative, and so far researchers haven't come up with a epidemiological link between these cases.
One avenue of investigation being pursued by the UKHSA is the possibility that a non-hepatitis virus (possibly an adenovirus) may be causing liver damage in these children. Other possibilities include SARS-CoV-2 infection, or some kind of toxic environmental exposure.
In Thursday's Eurosurveillance report from Public Health Scotland, we learned more about the suspected adenovirus link, and that a small number cases have also been reported here in the United States.
Although details on the U.S. cases until now have been scant, late yesterday Alabama's Department of Health released the following statement regarding their investigation into 9 young children who experienced liver damage following an apparent adenovirus infection.
HEALTH NEWS RELEASESNEWSROOMAPRIL 15, 2022
FOR IMMEDIATE RELEASE
CONTACT: Wes Stubblefield, M.D., (256) 340-2113
Since November 2021, the Alabama Department of Public Health (ADPH), in collaboration with pediatric healthcare providers including hospitals who treat children and the Centers for Disease Control and Prevention (CDC), has been investigating an increase in hepatitis in young children.These children presented to providers in different areas of Alabama with symptoms of a gastrointestinal illness and varying degrees of liver injury including liver failure. Later analyses have revealed a possible association of this hepatitis with Adenovirus 41.
To date, nine children less than 10 years old have been identified as positive for adenovirus and two have required liver transplants. The affected children were from throughout the state of Alabama, and an epidemiological linkage among them has not been determined. None of these children has had any underlying health conditions of note.
ADPH issued a Health Alert Network (HAN) notification on February 1, 2022, to elicit additional cases, and ADPH is updating the HAN for redistribution. ADPH continues to collaborate with the CDC. Other entities working with ADPH include Children's of Alabama and Texas Children's. New York State Health Department Wadsworth Center and the Infectious Disease Pathology Branch at CDC have been performing the testing on the specimens in these cases.
CDC is developing a national Health Advisory looking for clinically similar cases with liver injury of unknown etiology or associated with adenovirus infection in other states and is discussing similar cases of hepatitis potentially associated with adenovirus with international colleagues.
Adenoviruses are common viruses that typically cause a mild, self-limiting flu-like or gastrointestinal illness. Rarely, in otherwise healthy individuals, do these viruses cause an illness so severe that they need to be hospitalized and may die.
Adenoviruses are usually spread from an infected person to others through:
- Close personal contact, such as touching or shaking hands
- The air by coughing and sneezing
- Touching an object or surface with adenoviruses on it, then touching your mouth, nose or eyes before washing your hands
- Contact with stool, for example, during diaper changing
Adenoviruses are often resistant to common disinfectants and can remain infectious for long periods of time on surfaces and objects. Basic steps individuals can take to protect themselves from getting sick are as follows:
- Wash your hands often with soap and water for at least 20 seconds, and help young children do the same.
- Avoid touching your eyes, nose or mouth with unwashed hands.
- Avoid close contact with people who are sick.
Complicating the investigation, the CDC Adenovirus webpage states:
Adenoviruses is not a nationally notifiable disease in the United States, meaning clinicians are not required to test for or report cases to health departments or CDC. Therefore, many outbreaks of adenovirus likely go either undetected or unreported.
The good news here is that the CDC is developing a HAN (Health Alert Network) advisory, which should raise awareness among clinicians across the nation, and help identify other cases that may not have been otherwise reported.
While the adenovirus link is currently leading the suspect list, other causes - or even multiple causes - are still possible.
Adenoviruses - which are a common cause of (generally mild) respiratory and gastrointestinal illnesses in both adults and children - have occasionally been linked to acute hepatitis, although it is usually seen in immunocompromised patients.
This following summary of adenovirus types comes from the CDC:
Adenovirus types that can cause outbreaks
Reported sporadic cases and outbreaks of adenovirus have included:
- Adenovirus types 3, 4 and 7 are most commonly associated with acute respiratory illness.
- Adenovirus type 7 has been associated with more severe outcomes than other adenovirus types, particularly in people with weakened immune systems. In the last 10 years, instances of severe illness and death from adenovirus type 7 infection have been reported in the United States.
- Adenovirus type 14, which since 2007 has been associated with outbreaks of acute respiratory illness among U.S. military recruits and the general public
- Adenovirus types 8, 19, 37, 53, and 54, which can cause epidemic keratoconjunctivitis
- Enteric adenovirus types 40 and 41, which cause gastroenteritis, usually in children
- Some adenoviruses (e.g., 4 and 7) that spread in bodies of water such as small lakes or swimming pools without adequate chlorine and can cause outbreaks of febrile disease with conjunctivitis
According to a WHO Statement published yesterday, 3 additional cases have been reported in Spain, and more cases are expected to turn up now that the alarm has gone out.
The United Kingdom has reported 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 increasing trend in cases 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.
WHO is closely monitoring the situation with other Member States and the United Kingdom and partners for cases with similar profiles.
Hopefully we'll learn more when the CDC published their HAN Advisory.
