If you are a worrywart* like me, now we have an outbreak to go with our pandemic to occupy our attention.
Why is it Taking So Long to Figure Out the Hepatitis Mystery?
Given the nature of the cases and symptoms, we should expect answers to take a while longer. Factors working against a quick answer:
- The cause isn't one that is easily diagnosed with routine hepatitis testing, e.g. hepatitis A, B, C, D, or E. In fact, the case definition requires excluding these as a cause. If it were one of those, this would be relatively easy for epidemiologists.
- Hepatitis of unknown etiology is not a reportable disease, meaning we don't have prior data to know how unusual the current situation is. It took some early clusters in the UK and Georgia (US) with severe outcomes to bring this to global attention.
- Once a disease entity is identified as a concern, word goes out and then all kinds of reports flow in. This takes time to verify specifics and also makes it appear like everything is happening at once. Some of the reports are from older events, and it's even tougher to determine if they are connected to recent cases.
- Adenovirus, a prime suspect, is a tough diagnostic entity. After infection, live virus can normally persist in the host for weeks to months, and the same is true for PCR testing. Thus, a positive test may not reflect recent infection.
Response globally and in the US is proceeding as one would hope for an outbreak investigation. Recently, the ECDC (European Centre for Disease Control) and the WHO joined forces to work on this. Individuals and organizations must apply for access to ECDC data, and I'm too lazy to do that. Instead, I look for my all-time favorite International Society for Infectious Diseases ProMED system to keep me current. Look at their first topic in the posting from last Friday and scroll down to the case numbers by country. Also, a little bit farther down are the adenovirus testing results. Now you get an idea of why this is so complicated and tedious.
CDC also is working hard on this, and I'd recommend all practitioners and any interested parents to look at their general overview. In particular, parents should note the signs and symptoms to look for in a child with hepatitis. Case definitions for reporting purposes vary slightly between Europe/WHO and CDC and likely will change as we learn more about this entity. Primary care providers should make liberal use of their pediatric GI and ID consultants for help. At Children's National we are working on clinical guidelines to assist both our internal as well as community providers.
A Few COVID Publications of Note
In my quick read through the Moderna vaccine results for 6-11 year-old children, it seems likely to be authorized by FDA for this age group. Of course, FDA has access to the raw data not provided in the article, so we do need to wait for their review. It's nice to have another option for this age group but of course we still want to see the data for children under 5 from both Pfizer and Moderna.
Two new reports appeared in JAMA this week, both related to vaccine effectiveness (VE) in children during the omicron period. One from CDC showed that VE for symptomatic infection in children and adolescents during the omicron period was modest but decreased fairly rapidly. For children 5-11 years of age, VE was 60% (95% confidence interval 55-65%) at 2 to 4 weeks post dose 2 and for adolescents also about 60% (44-71%). For the younger group 2 months after dose 2, VE dropped to 29% (24-33%). Adolescent data showed VE 17% (8-24%) at that time. However, data on adolescents who received a third (booster) dose showed at 2-6.5 weeks after booster VE was 71% (65-76%). That's more encouraging.
The second report was from New York state databases and looked at hospitalization rates for children 5-17 years of age. Although hospitalization rates were low in this group, it was very clear that completion of a primary vaccine series was significantly protective.
The accompanying editorial also was interesting. Vaccines clearly are important for children and adolescents. Now we just need to do a better job of getting this message across.
*Being the conscientious infectious diseases practitioner that I am, I was interested in the etiology of this particular wart. Apparently (I can't quite verify accurately) the term arose from a 1920s comic book series where the annoying protagonist caused others to worry.
We see so many patients with vomiting at PM Pediatrics. We are interested in any guidelines you might have to share.
Thank you!!
Rebecca Carlisle
Rcarlisle@pmpediatrics.com
Dr. Carlisle asks a very key question. This reflects the problem with providing the general public with warning signs to look for in their children, knowing that some of those warning signs are very common with many other illnesses. Although we don't yet know the incidence of this unexplained hepatitis issue, it is certainly far less common than all the viruses out there that can cause vomiting in young children. So, while a parent may use that symptom as a trigger to seek medical attention due to concern for hepatitis, the front-line providers are stuck sorting this out and deciding how far to explore the possibility.
Vomiting alone is unlikely to be the only symptom of this clinical entity (if it truly is a distinct entity); in general, fulminant hepatitis has more dramatic symptoms developing over a few days. On the flip side of that, the classic presentation of hepatitis A that I use in teaching settings is the toddler in day care who has 4 or 5 days of vomiting, maybe a little decreased appetite, and then gets better. The physician finds nothing of concern on exam and nothing is done. Four weeks later the parent develops vomiting, jaundice, and acholic stools, and then the diagnosis of hepatitis A is made retrospectively in the child. This is because hepatitis A tends to be mild and anicteric in toddlers.
If an etiology is ever found for the current cases then we may find a broader spectrum of the disease including very mild cases, but presumably those children are fine without having a large workup. So, if you are suspicious this goes beyond the typical acute illness with some emesis, you might want to obtain CBC and comprehensive metabolic panel to screen widely. If you pick up someone with AST or ALT above 500 that may be the time to look more closely and/or call your friendly specialist.