Good news this past week with FDA authorization of COVID-19 boosters for the 5-11 year olds, but don't take your eye off the more important issue of improving the primary vaccination series rate for this age group, currently sitting at a dismal 28%. An important take home from the ACIP meeting was continued evidence that the vaccine is safe in this age group with overall lower rates of myocarditis compared to adolescents and young adults. I'm still waiting optimistically for next month's meetings about vaccine in the youngest age groups.
In the meantime, my attention increasingly is focused on new outbreak developments.
Monkeypox
In the late 1960s/early 1970s I had the amazing good fortune to spend a few summers working in a world-class virology research center, undoubtedly sowing the seeds for my future interests. I was basically a glorified research assistant helping a veterinarian studying herpesviruses, but I was also surrounded by other labs dealing with mysterious (to me, at the time) organisms. The monkeypox facility was nearby, a high level biosafety lab that required me to don full Andromeda Strain garb when I went in to borrow equipment.
Monkeypox, an orthopoxvirus and cousin to smallpox, usually occurs in residents in or travelers from the West African and Central African countries where it is endemic. Cases turn up in the US sporadically. However, now we are seeing small clusters of infected individuals turning up in many different countries - Spain, France, Belgium, Germany, Italy, Sweden, Portugal, UK, Canada, US, and Australia so far. We haven't seen anything like this before and it is likely we will see many more cases around the world. Current affected individuals have been predominantly young men with an overrepresentation of men who report sexual contact with other men. Early testing suggests these cases may involve the West African strain which has a lower mortality (about 1%) compared to the Central African clade (up to 10% mortality). An antiviral medication, tecovirimat, has FDA approval for treatment of smallpox and likely would be effective against monkeypox; the approval was based in part on animal studies of monkeypox. Vaccines against smallpox and monkeypox are likely to be effective in preventing disease, though I doubt we'll need that option in the US. Monkeypox is not highly contagious, it requires close contact. However, if you think you are dealing with a case, institute full infection control with gown, gloves and N95 mask protection while you are calling for assistance.
Monkeypox infection is fairly distinctive, usually with systemic symptoms of fever, chills, lymphadenopathy, and a vesicular or pustular rash. It may be confused with secondary syphilis, HSV, chancroid, or varicella zoster infection. The CDC website is useful. If you think you might be dealing with a child or adolescent with monkeypox, call me (or your nearest pediatric infectious diseases specialist).
More on Severe Hepatitis Cases
Investigations are ongoing attempting to uncover the etiology of clusters of severe hepatitis in young children in the US and worldwide. CDC provides weekly updates. Since I mentioned this last week, we don't have any breakthroughs yet. However, I've been working on a guide for clinicians to facilitate identification and evaluation of cases. I offer what I have so far to aid in evaluation at the front lines of care in office practices, urgent care, and emergency departments.
First, I made up a name for this: Pediatric Hepatitis of Unknown Etiology (PHUO). Certainly someone more clever than I will come up with a better acronym. Potential cases (termed Person Under Investigation, or PUI) currently are defined as children under 10 years of age with AST or ALT >500 U/L. If you are dealing with that, it's time to consult with a subspecialist, but the issue is how to get there in an efficient manner without testing every child who vomits once or twice. To do that, it's helpful to know what cases so far have looked like.
In a cluster of 9 cases of PHUO in Alabama, common symptoms were emesis (78%), diarrhea (67%), fever (56%), and fatigue (44%), with small numbers of upper respiratory symptoms, poor appetite, and dark urine. On exam, icterus/jaundice was present in most (89%) and hepatomegaly in 78%, with splenomegaly and hepatic encephalopathy also noted at presentation in small numbers. A detailed report from the United Kingdom noted similar numbers and mentioned pale stools in 50% of 450 cases under investigation. Two-thirds or more of the children in Alabama and the UK were under 5 years of age.
As you may deduce from the percentages, children seldom exhibited just one sign or symptom; multiple were present. A frontline provider evaluating a child with a compatible clinical picture as above should obtain further history for travel, environmental exposures (e.g. pesticides), family history of liver disease, and other details. Assuming the child shows no signs of liver failure such as mental status changes or bruising mandating immediate attention, it would be prudent to consider obtaining initial laboratory studies to include CBC with differential and comprehensive metabolic panel.
Consultation with a pediatric subspecialist may be helpful at any time, but if the initial evaluation meets PUI criteria then referral to a tertiary pediatric center should be made.
It's a hot afternoon ahead in beautiful downtown Silver Spring. Maybe I'll look for a good sci-fi movie on the tube. (That last word really dates me!)