Parechovirus and Monkeypox
More context, less fear
Post-COVID, we have all become more aware of viruses. Which is in many ways good — my guess is that flu season is going to be more limited going forward — but isn’t without challenges. In particular, the past two years have dramatically dialed up the fear that accompanies any illness threats. This would be true even without any outside intervention, but in some cases media coverage stokes this fear, partly by not providing enough context to the coverage.
Today I want to talk about two of these fears that parents have been bringing to me: parechovirus and monkeypox. As parents of small children (which most of you are), how much should these change your behavior?
Little kids get sick a lot — colds, stomach bugs, etc. A large share of these illnesses are viral. We do not, perhaps, think very much about exactly which virus is responsible. Most of the time, when kids are sick, even when they are quite ill, we do not test for which virus is responsible. The medical advice, in many cases, isn’t dependent on which virus is causing the fever or respiratory or stomach issue.
I start with this background because, even though it may be new to you as of last week, parechovirus is actually one of these common childhood viruses. Effectively all children will have had the virus before they are in kindergarten.
Given this, why are you hearing about it now?
Last week, the CDC issued a health alert for medical providers, highlighting the fact that parechovirus has been circulating in the U.S. and that it can cause serious illness in infants, especially those under three months.
These health alerts occur regularly and are an important way that the CDC informs medical providers about possibilities that they may not be aware of. You can read an archive of them here. They are quite varied. For example, in 2018 one alert discusses the possible risk of leptospirosis in travelers returning from Israel. This is a very rare bacterial infection with somewhat non-specific symptoms (fever, vomiting). Because it is very rare, most clinicians wouldn’t consider it as a cause unless they knew it was a possibility. So the alert says, basically, “Hey, if you see someone who traveled to this location and has these symptoms, consider this diagnosis as a possibility, and here is the treatment.”
This is all important background because it makes clear that the CDC health alert isn’t triggered by a particular number of cases, or the size of a risk. It can be; but in many cases they are brought on by a change in the presentation of an illness, or a novel explanation for a common set of symptoms.
The CDC alert on parechovirus can be read in full here. The alert doesn’t refer to a particular number of cases and notes that it is difficult to know even if cases have increased, since we don’t routinely test for parechovirus in kids. What they want clinicians to do is be aware of it as a possible cause for very sick infants. Treatment is not likely to be affected by this knowledge, but it would (for example) help rule out a bacterial infection as the cause.
Is there anything you should do here, differently from what you would do normally?
Normally, with an infant, some illness precautions are useful. It’s generally a good idea to try to keep newborns protected within reason (i.e. you don’t need to pull your toddler from preschool, but if they are sick, try to keep them a bit apart — more on that here). Similarly, if you have a small infant who is sick, you should let your doctor know — and if your child is very sick, you should take them to the ER. This is true regardless of what virus you think might be causing it. But the fact that the illness could be parechovirus should not change your behavior.
For me, this is an example of a place where the CDC did exactly what they should do. They have an alert system and they implemented it as they should. My only comment is that when media is reporting on this, it would be good to have more of that context.
The monkeypox virus is a close relative of the smallpox virus. It’s a virus endemic to West and Central Africa, typically spread through close contact or animal contact in these locations. In Africa, it does commonly affect children and can be serious or fatal. Until early 2022, virtually all cases of monkeypox outside of Africa were clearly imported from affected regions.
Beginning in the spring of 2022, monkeypox began to spread in a large number of locations outside of Africa, with cases arising in the U.K., Portugal, and then the U.S. It was clear that these cases were spreading locally — were not imported — and the World Health Organization recently declared it a global health emergency. This declaration will enable better global coordination and more funding.
There are vaccines for monkeypox (it’s some of the same vaccination store that is relevant for smallpox), which are being offered to high-risk individuals. There are also available treatments. There have been a lot of issues with appropriately rolling these out — issues that are familiar from early on in COVID — such as lack of testing and poor communication. We are ahead medically on monkeypox, but we cannot allow these same failures to play out again.
Here, though, I want to address a very specific question about monkeypox, which is how afraid you should be about it for your children. I get a number of questions along these lines — i.e. should I cancel my trip to San Francisco with my six-month-old because of monkeypox? And online, fears have been stirred about the risks of monkeypox with school reopening.
Given what we know about the data, fears of in-school spread are misplaced. Notably, the spread of the virus so far seems to be through prolonged close, skin-to-skin contact (largely but not exclusively sexual).
The vast, vast majority of cases we have seen are in men who have sex with men, and the spread is through close contact. In the most recent update from the U.K., of the roughly 2,000 cases, 13 were in women. Of the 549 cases with more detailed epidemiology, 96.5% were in men who identified as gay or bisexual, or in men who have sex with men. There is, thus far, one pediatric case reported in the U.K. (no details available).
In last week’s U.S. briefing on this, the CDC reported similar numbers: 99% of cases in men who have sex with men. They were aware of two cases in children who were household contacts, eight cases in cisgender women, and five cases in transgender men. The overall global WHO numbers tell the same story, and if you want to dive into the data, this project is compiling details on all the cases of monkeypox reported globally.
The most detailed data we have on transmission is from this New England Journal of Medicine paper, which discusses 528 cases from 43 countries in detail. All cases were in men. In 95% of cases, the suspected transmission was through sexual contact.
It is important to emphasize that even though monkeypox has been seen predominantly in one particular community, that does not mean it is limited to that community. It can, and has, spread outside this group. Prolonged close contact can occur in the household, and the two U.S. cases in children reflect household transmission that is not sexual. The CDC has reported one case in a pregnant woman (details about transmission were not available at this time). And also none of this is to say we should not be aggressive at containing the outbreak, both in the U.S. and worldwide.
However: based on what we know at the moment, having looked at thousands of cases, it seems clear that the virus requires sustained close, skin-to-ski contact to spread. Contact much closer than would be expected in schools or in casual interactions.
A family trip to San Francisco does not put your six-month-old at risk of monkeypox. Closing elementary schools will not lower the transmission of monkeypox (even putting aside all the reasons not to do that).
There is a significant public health messaging challenge here. On one hand, public health officials want to avoid giving the impression that monkeypox is a disease only affecting a particular demographic or that it is only spread through sex. This creates stigma, and it limits our ability to fight the outbreak. For example, people who are infected with monkeypox should take steps to protect their close household contacts, even if those household members are not in the highest risk demographic.
On the other hand, at least in my view, we also want to avoid generating misplaced fear. Doing so erodes trust, which we sorely need in public health. Many people who DM’d me about monkeypox spread in schools assumed that there had been a change in transmission patterns — that it was spreading in schools. That’s not the case, though, and once that becomes clear, the next message is going to be met with more skepticism.
In the end, it may be necessary to thread the needle: to be clear on the risks, and the need for better policy, but without misinformation.