Expert explains how to prevent tick-borne illness

[00:00:00] Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Powassan virus is a rare disease spread by ticks, but it can be deadly. The first fatal case of 2023 was confirmed in Maine. To learn more about Powassan virus, I'm turning to Upstate's tick and Powassan virus expert, Dr. Saravanan Thangamani. He's a professor of microbiology and immunology at Upstate, and he's director of the SUNY Center for Vector-borne diseases. Welcome back to "The Informed Patient," Dr. Thangamani.

[00:00:41] Saravanan Thangamani, PhD: I'm glad to join you and discuss about Powassan virus.

[00:00:44] Host Amber Smith: Some of the symptoms of Powassan virus are pretty scary. Can you go over them with us?

[00:00:50] Saravanan Thangamani, PhD: Well upon a tick bite if the tick is infected at the Powassan virus, in the next week to three weeks, one would actually have initial symptoms like fever, headache, vomiting, and muscle weakness. It's like any other acute febrile illness. But if the disease progresses to to the next stage. That is a stage the virus enters the brain or spinal cord, causing meningitis or meningoencephalitis. So those are the worst case scenario where the virus infects the brain and spinal cord.

[00:01:22] Host Amber Smith: So how long might it take for some of these symptoms to appear?

[00:01:26] Saravanan Thangamani, PhD: Between one to four weeks after a tick bite.

[00:01:29] Host Amber Smith: So it could be quite a ways distant. You might not remember that you had a tick bite?

[00:01:34] Saravanan Thangamani, PhD: Absolutely. Even in a normal situation, it's very difficult to know if you had a tick bite or not, unless and until you do a regular tick check and other things. So in this case, yeah, it could be, it's highly possible that one would not remember that they had a tick bite. And then when they go to a clinic or when they're hospitalized, two to three weeks post a potential tick bite.

[00:01:55] Host Amber Smith: There was the death in Maine earlier this year from Powassan virus, but what percentage of people who are in infected will go on to have either lasting brain damage or go on to die from the virus?

[00:02:10] Saravanan Thangamani, PhD: From the data that I have access to, nearly 15% of the human infections can result in death. And 50% of the survivors could actually have long-term neurological complications as well. So it is a rare disease to get, but it can be fatal in 15% of the cases approximately.

[00:02:36] Host Amber Smith: So it sounds like it's something we should take seriously.

[00:02:41] Saravanan Thangamani, PhD: Absolutely. Absolutely. So the one thing that I always tell people when it comes to the tick tick-borne viruses, is that unlike Borrelia, the Lyme disease causing agent that takes about 24 hours to 48 hours post a tick bite. It gets transmitted to the human skin. But in this case, viruses are transmitted immediately upon tick attachment. So it is very important to be aware of where we are venturing outside, how to prepare ourselves in such a way that we don't get any tick bites. Because here, as soon as the tick bites, it disseminates the virus into the human body.

[00:03:19] Host Amber Smith: Wow. Once someone is infected with Powassan virus, are they infectious to other people?

[00:03:26] Saravanan Thangamani, PhD: In a traditional sense, they are not infectious because person-to-person transmission has never been reported for Powassan virus. However, if someone is donating blood, they may have to wait for at least four months before they can donate blood.

[00:03:40] Host Amber Smith: Let's talk about how it's diagnosed. If someone goes to the doctor with the symptoms of Powassan, how would a doctor confirm that that's what they have?

[00:03:49] Saravanan Thangamani, PhD: I think this is a great question because oftentimes most of the Powassan cases, they go unnoticed or misdiagnosed because of the fact that the initial symptoms from this virus infection mimics many other disease symptoms.

So unless and until the clinician has a prior knowledge or the patient has a prior knowledge in such a way that the patient is coming from a Powassan virus-endemic area and the person may have encountered a tick. Then the clinician has a higher chance of prescribing a diagnostic test. So that's why it is very important to know if someone got a tick bite or not. So if someone gets a tick bite and someone goes through this acute febrile illness, normally the traditional way of checking is to take the spinal fluid and then look for markers of Powassan virus infection.

That's how you normally look for a acute phase infection, because virus will actually move away from the blood very quickly. So the virus, it will be in the human blood only for a short period of the time. So if the patient doesn't go to the clinic at that particular window of time that no one can predict, it's impossible to detect. So for Powassan virus infection, the primary way of collecting sample is spinal fluid, and then look for infection markers.

[00:05:06] Host Amber Smith: So it moves from the bloodstream into the spinal fluid?

[00:05:11] Saravanan Thangamani, PhD: Exactly. So it moves quickly from the skin. It actually goes to the spinal cord and then to the brain. So it stays in the bloodstream only for a short amount of period.

[00:05:22] Host Amber Smith: Does the human immune system fight this?

[00:05:27] Saravanan Thangamani, PhD: Yes, our immune system fights it. So what we think is happening is that the asymptomatic infection, or people who never end up in hospital due to Powassan virus result of their body responding to the infection.

So if someone is healthy and very responsive, their body immune system will attack this virus and eliminate it from their body. So they might have just an initial symptoms, but they would recover like a flu, right? You are sick for a few days and then we recover.

However, if it's a person who is immunocompromised for either cancer therapy or immunotherapy or old age, they will succumb to the disease. The virus will actually march from the skin to the spinal cord to the brain.

So I think that is one good thing that I want to highlight here is that majority of the Powassan virus infection are in the population about 60 and 60 and about years old. Because their immune system is weakened at the time. So that kind of answers your question.

[00:06:25] Host Amber Smith: Well, are there medications that can be used to treat someone who's in the hospital with Powassan virus?

[00:06:32] Saravanan Thangamani, PhD: Unfortunately not. So only supportive therapy, fluids and hospital care is only way. There is no vaccine. There is no therapy. And antibiotics will not work because these are viruses. Antibodies will work only against bacteria. So basically supportive therapy is the only therapy we have at this time.

Is Powassan virus a threat to dogs and cats? They are not threat, as threatful as they are to the humans, but they do get Powassan virus infection, but their body clears it because in our surveillance program, we have received ticks that fed on dogs and cats that there are positive of Powassan virus. However, they never got sick. So, which means that it's like any other reservoir animals, that they would recover from the infection.

[00:07:19] Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with Dr. Saravanan Thangamani. He's a professor of microbiology and immunology at Upstate and director of the SUNY Center for Vector-borne Diseases.

Which ticks carry the Powassan virus, and how do the ticks get it to begin with?

[00:07:39] Saravanan Thangamani, PhD: There are three ticks that we believe transmit Powassan virus -- the groundhog tick, the squirrel tick, and the deer tick. And deer tick are the ones that humans often encounter. Groundhog tick and squirrel ticks are rarely encountered by humans. So those two ticks are normally one would encounter if they're a hunter or a logger because they are normally deep in the woods.

Deer ticks are the ones that often people encounter, both in the rural and urban settings. So how do ticks acquire the virus is the objective of my lab's research, and we are trying to answer that. That is the question we don't know. Scientists like me, we don't know exactly how ticks acquire and why the Powassan virus infected ticks are perpetuating in a small environment or micro foci environment, compared to Lyme disease agent that are throughout the state.

So we are trying to decipher that and what are the factors that determines that. We still don't know what are the amplifying reservoirs for the virus. Like for Lyme disease agent, we know the white-footed mouse are the reservoirs for the agent. But for this particular virus, we don't know. So that is one of the research objectives of my laboratory.

[00:08:54] Host Amber Smith: Do you know how common it is for a tick that carries Powassan virus to also have other pathogens?

[00:09:01] Saravanan Thangamani, PhD: Oh, I must tell that pretty much 80 to 90% of the Powassan virus infected ticks, they do carry either a Lyme disease agent or anaplasma or a Babesiosis agent. So they often actually come together with other agents.

[00:09:17] Host Amber Smith: So, again, to go over this, if a person has a tick bite and that tick is infected with Powassan, immediately they have that virus in their system, but if they remove the tick that afternoon, they might not have the Lyme disease pathogen transmitted?

[00:09:36] Saravanan Thangamani, PhD: Absolutely you're right. So tick-borne pathogens are delivered in a, I would say, timed delivery mechanism. The first one that is delivered is a virus, followed by anaplasma agent, the agent of anaplasmosis, followed by the Lyme disease agent. So immediate, 12 to 24, 24 to 40 hours post tick bite. These are like timed delivery of a pathogen from a tick to a human.

[00:10:02] Host Amber Smith: Well, let's talk about prevention because that seems like maybe the best way to deal with this. What is your advice to prevent tick bites from, let's say, deer ticks? Because that would be the most common way someone in Central New York might catch Powassan, right?

[00:10:18] Saravanan Thangamani, PhD: Absolutely. Prevention is the only way. So that's what I would like to educate people is that because we don't have vaccine for any of the tick-borne are causing disease in the North America.

So prevention is the best way. And the first thing to know is where the ticks are, where are the hotspot for human tick encounters? So we need to know that, and that is what our citizen science is helping people to know where are the hotspot so they can try to avoid it.

The second one is that before getting out of your house to do an outdoor activity, make sure that you have a tick repellant spread on your exposed skin areas. Also, make sure that the outdoor clothes are treated with permethrine. These information are available through a CDC website, and the concentration that need to be treated as well.

And then when they go for trail walking or trekking, to stay in the middle of the trail rather than the edges of the trail. Ticks are waiting at the edges of the trail. And if we walk with the dogs and pets, it's best that we keep a tight leash on them, particularly in the areas that we know that can have more ticks, because pets are tick magnets. When they walk off the trail edges and come back, they will come back with the ticks. So it is very important that we also do tick check on them. Also, keep them on a tight leash in a way.

And then upon coming back to home and after outdoor activities, important to do tick check on themselves, take shower, and put our clothes into the dryer for at least 10 minutes at a high heat to kill off the ticks. And do the tick check on the pets as well.

[00:11:51] Host Amber Smith: What do you tell people to do if they find a tick?

[00:11:55] Saravanan Thangamani, PhD: So I tell them to gently pull the tick, either with the blunt-end tweezers or sharp-end if they're using sharp-end tweezer, I tell them to be careful so they don't poke themselves. Pull the tick gently upward from the skin, and then as slow as possible in such a way that they pull the entire mouth parts as well, because ticks are very clever. When they attach themselves into the skin, they actually secrete a substance called cement protein -- they are like glue -- so to secure themselves strongly onto the skin. So it's important to pull gently and swiftly, at a right angle, or perpendicular to the skin.

And then, do a gentle soap wash at the site of a tick bite or alcohol wash there. And then keep the tick in the fridge in a Ziploc bag and send to a lab for tick testing. It is important to actually test the tick that bit them so that they can actually assess the risk. They can only assess the risk. It's not a direct correlation that if the tick is carrying an agent, it doesn't mean that human got the agent as well, but it actually gives them a risk factor. So that information, if that is relayed to the clinician, the clinician then make an informed diagnosis based on that information.

So I would definitely recommend the public to pull the tick, gently save it, and then send it to a tick testing facility to get it tested.

[00:13:09] Host Amber Smith: But there's no need to contact your doctor just to report that you had a tick bite if you're not having any symptoms, right?

[00:13:18] Saravanan Thangamani, PhD: Yes. I would definitely say that post tick bite, I would definitely advise the public to monitor any symptoms of sickness for 30 days. And if you, if anyone sees sickness or anyone feels like they are sick, they need to contact the healthcare provider right away. But it's important to monitor the symptoms, acute febrile illness symptoms, for at least 30 days post tick bite.

[00:13:43] Host Amber Smith: Now the person who died with Powassan virus earlier this year lived in Maine. Do we have ticks carrying Powassan virus here in Central New York?

[00:13:53] Saravanan Thangamani, PhD: Yes, of course. So New York is one of states that have high rate of Powassan virus infections in the United States. It used to be primarily in the lower Hudson Valley, but now from our research we are able to detect Powassan virus infected ticks, even in Central New York, even in Onondaga county.

[00:14:12] Host Amber Smith: So does it look like their numbers are increasing?

[00:14:16] Saravanan Thangamani, PhD: Yes. That's what our surveillance is telling. So based on our citizens and surveillance data comparing to 2019, 2020, 2021, 2022, we see a trend in the increasing number of ticks that are submitted to us. So I can confidently say that in the future, in the near future, the number of Powassan virus infections will increase.

[00:14:35] Host Amber Smith: Well, Dr. Thangamani, you're always very informative. Thank you so much for your time.

[00:14:40] Saravanan Thangamani, PhD: Thank you. I appreciate having me again.

[00:14:42] Host Amber Smith: My guest has been Dr. Saravanan Thangamani, professor of microbiology and immunology at Upstate and director of the SUNY Center for Vector-borne Diseases. "The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at 1e1v.com/informed. This is your host, Amber Smith, thanking you for listening.