Increase In Powassan Virus In Maine?

Is your inner anxiety not yet up to "impending catastrophe?" Are you not watching enough political media to make your blood boil? Here's a new threat, possibly lurking in your backyard, Powassan virus!

The earliest mention of Powassan Virus in online medical journals is from 1959,  when it was first named after a town in Ontario where it was found. That 1959 medical article mentions that Powassan had probably been around for decades. So why are we hearing so much about it now?
Well, we've just had two cases of Powassan in Maine. By just, I mean that we just had two more cases. Two earlier cases this year were reported in a Bangor Daily article back in April. Those were from around Portland, and these two new ones are from the midcoast region. Bringing our total for the year to four cases.
At the same time, we're counting hundreds of Lyme cases, so why do we care so much about Powassan? Well, according to the CDC, Maine only had two Powassan cases IN THE PAST TEN YEARS. So the four this year brings our total up 200%.

Is Powassan a true terror? Yes and no. It's not new to Maine, and previous surveys have found it widely spread (but not very common) among Maine's tick populations. We had another notable outbreak at the turn of the Millenium, four cases that included both Maine and Vermont. Checking residents, between 1% and 4% of Mainers likely have antibodies to Powassan.

But Powassan is scary because it's viral and we don't have a good treatment. Arguably, we don't have great treatments for Lyme either, but that's a whole different issue (a bit more on that later).

If you get Powassan, you very likely won't get symptoms. If you do get symptoms, they feel like the flu and you'll likely recover. But if you get symptoms and your body doesn't kick it, there's very little modern medicine can do for you besides support you. Just like any number of other viruses.

If it starts to feel vaguely familiar, it should. Powassan is a flavivirus. Yes, like Zika virus. Different subspecies, same family. Powassan's flaviviral branch includes Russian spring-summer encephalitis, Central European encephalitis, Omsk hemorrhagic fever, Kyasanur Forest disease, and Powassan. Just reading through its close family members, you should get the sense that Powassan is likely coming from a more northern branch of the flavivirus family than Zika.

 
Also notice that every one of these viruses has a pretty scary-sounding name. Omsk hemorrhagic fever sounds like a reason to never, ever visit Omsk, which Dostoevsky immortalized as "a hateful hellhole" but which likely influenced all his writing since he was imprisoned there. (They now have a museum for him.)

A large part of the problem of the flaviviruses is that we're still assigning every member of the flavivirus family a new name. Think about the flu viruses. We had swine flu, avian flu, etc. and they sound much scarier than H1N1, which is another variation of the same family of viruses. All of the flaviviruses should be assigned a number so that we understand that this isn't a total unknown, this is another member of a well-known and widespread set of viruses that have been with humanity for centuries. Public health officials have started the process by labeling the four different strains of Dengue fever (another flavivirus) one through four rather than giving them all different names like the four horsemen of the Apocolypse.

According to the CDC, "Powassan (POW) virus is transmitted to humans by infected ticks. Approximately 75 cases of POW virus disease were reported in the United States over the past 10 years." So our four cases of POW will really make the news. Maine, home of the Whoopie pie, the lobster roll, and the obscure tickborne illness. Is this really what we want to be known for?
So, should we just watch out for ticks to protect ourselves from Powassan? Maybe. I would argue that the flaviviruses are largely misunderstood as only vector-borne diseases. I've mapped this out in Zika Virus When You're Expecting and I talk about focusing on just ticks in Why Chronic Lyme Doesn't (And Does) Exist. Blood-born diseases need to be seen as more widespread and contagious than we'd like to think. 

But, because they are much more widespread, they also may be much less deadly than they would appear from the very few serious cases that get reported. Powassan reports of serious side effects may indicate a spread of the disease in Maine. But the number of symptom-free cases of Powassan will continue to dwarf the number of serious reported cases.

Should you worry about Powassan? No more than you would about getting a serious flu and not recovering. While this year in Maine we had four hospitalizations from Powassan, we also had 586 hospitalizations for the flu.

For the few of you heedless folk who ignore the Lyme warnings, who've still been frolicking in the buff in tick-infested fields, I doubt if the added threat of Powassan will convince you to change your behavior. For those of us who are already avoiding the fields and doing tick checks, don't let the fear of more rapid transmission of Powassan panic you. Continue doing what you've been doing, and take care of yourself if you get sick. As a virus, all of the things you would do to help yourself get better from the flu would apply to Powassan too.