by Barbara Ebel
She changed the slide to an expansive aerial view of the cold continent of Greenland with the section of earth she alluded to.
“Now bear with me. Although I am an old lady, don’t underestimate me. My roundabout way to get to the infectious diseases that came to light for Dr. Mejia and Dr. Schott’s team this month is not unwarranted. My wits are with me and I will paint the entire picture which precludes the story of the foxy diseases I will present. Yes, they are clever!
“I say ‘foxy,’ which means clever, and although I could possibly use fox in my discussion, I am going to instead bring in the white-footed mouse. Because … my main patient with today’s premier infectious disease presented with an unknown history to us of having been knee deep in their environment. So much so, that he was trying to cull their population from the grounds where he lives.
“Our patient is a thirty-five-year-old Ohio National Park Ranger,” she explained, “who helps maintain the inner workings and tours of a former presidential home as well as sees to the outside grounds and safety of the nearby woods and trails.
“Anyway, getting back to climate change and the white-footed mouse.” She popped up a picture of a horde of scurrying mice. Many medical students were previous biology majors, so she knew she had a captive audience interested in animals, their behavior, and their range.
“What heavily influences a species’ life cycle? Climate! Over time, the weather dictates the environmental conditions which affect an organism’s reproduction, behavior, phenology, physiological tolerance, and its sensitivity to habitat quality and food supply.
“And above all … its absolute survival. Because of recent climate change, fluctuations in the weather are faster and of greater amplitude than ever, ever before in the entire past. This affects the distribution patterns and niches of a species.
“Scientists have empirical evidence which is mounting by the day that the earth’s species are responding to climate warming and the temperatures have already had a dramatic effect on the flora and fauna of geographical regions in the 20th century.
“What’s going on is that the stability of a species’ niche is being challenged. Its tolerance and adaptability is being pushed to its outer limits. They shift themselves poleward or upward in their geographic elevation. At the same time, this climate change increases the ability for invasive species to establish themselves in new areas.
“A stark example of a species shifting poleward in its distribution is the successful Eastern North American native rodent, the white-footed mouse. Scientists have calculated his increased and expanded rate of migration on the Upper Peninsula of Michigan for the last forty years. Records also document his northward trek in southern Quebec. The numbers are quite appalling.
“The white-footed mouse usually lives a couple of years, but in northern climates it lives a bit less - one or two years. They eat insects and seeds and, in particular, gather and store seeds and nuts in the fall. They often live in the walls of apartments and homes where they store their food and build their nests and are also the most abundant small rodent in mixed forests in the eastern United States. And, last year the northeast had a record abundance of acorns, which fueled them into a booming population explosion!
“On the other hand, their usefulness is that they eat fungi and spread the spores on the ground in their droppings. This allows local trees to gain nutrients through their roots. They also do eat harmful insect pests and do not engage in harmful activities towards farmers’ crops.
“So what’s the big deal and why do I bring up these mice? The significance is that their northern migration is a public health concern!
“And everything is interconnected, isn’t it?”
She gave them a moment to think about that and began again and said in a louder voice and with more passion:
“The prolific, northern migrating white-footed mouse is known to be the main host for Ixodes scapularis, the black-legged tick at the larval stage. And each summer, fall, and spring, the tick population increases because of milder winters and the growing mice and deer populations. Dozens of ticks can attach to a single rodent!”
Dr. Enno skipped ahead to her first photograph of the life cycle of her publicized tick. Of the larva, nymph, and adult male and female tick, the larval stage was the beginning of the cycle and the tiniest specimen on her slide of the entire life cycle.
It gave Annabel the creeps to see the slide with the little vampire, especially the premature size of the larva; she glanced at Bob and shook her head while Bob shuddered.
“The thirty-five-year-old male national park ranger who presented to our medical team first presented to the ER staff with flu-like symptoms. He was sent home with instructions to get rest and to treat his cold symptoms. He came back approximately one week later with worsening symptoms - a fever, headache, vomiting, and central symptoms such as slight memory problems.
“As far as preliminary testing suggestive of an encephalitis, an EEG and an MRI were useful, but a brain CT fell short of being helpful. And to the gloom and frustration of our team, and to the jeopardy of our patient, he soon lapsed into a coma and was in the ICU on life support.
“As most of you can appreciate, the possibilities, the cause of his situation and diagnosis, were prolific. And time was of utmost importance to discover and treat his disease. Would this man succumb to his death, stay unconscious for the foreseeable future, and/or could we start him on an antibiotic and reverse his path of ruination?
“As Mr. X’s day by day hospital course unfolded, the internal medicine team worked their magic to keep him alive with respiratory support, intravenous fluids, and drips to decrease intracranial pressure while I chipped away at unearthing and discarding possible diagnoses. But here is where I tell you physicians and students-in-training that the history of your patients is of paramount importance.
“From our patient’s coworker - a woman who lived in one of the cabins of the national park like our patient - we later learned two important aspects of Mr. X’s lifestyle.
“First, as part of his park responsibilities, he was practicing extermination techniques on the white-footed mouse living in the park and their cabins - the very rodent so incriminated in carrying the dreaded ticks, which cause severe illness in humans.
“And secondarily, our patient is a deer hunter. According to the time frame of a recent bow and arrow expedition he had taken, and the fact that he spent the latter part of an entire day hauling in a buck, and skinning and processing it, his body could have become the habitat for one tick or multiple ticks from his activities with either the mice or the deer. In addition, even from the dogs the rangers take care of on their property.
“We know for a fact from his coworker ranger friend, that on the day of his last deer hunting expedition, he pried ticks off of his body. No one likes to do that and people unaccustomed with these critters sometimes don’t even know what they are. However, I am sure our patient knew what he was dealing with, and most likely took certain preventative measures, which were not one-hundred percent effective. We will talk about that and I’ll give you my two-cents about alarming your patients to the vastly increased threat to them regarding ticks.
“So, back to the possible diagnosis. Much to our disappointment, and along the course of our patient’s workup, bacterial infectious diseases were eliminated as the culprit. He failed courses of antibiotics and continued to lie in his stuporous state.
“At the core of helpfulness in a situation like this is a patient’s own immune system. As we are at a loss with discovery, his or her own body is at war with whatever is slinking around in their bloodstream. An immune response is generated against the foreign substance … cells such as those from the thymus, spleen, lymph nodes, and lymphocytes become warriors against the invasive intruder and, most importantly, antibodies are formed. These high molecular weight proteins, normally produced by B cells, act specifically against the antigen and can be detected by laboratory tests of blood or spinal fluid.
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“Thank goodness for the specificity and know-how which emerges from our CDC. They are at the forefront of new, emerging diseases, and have the wherewithal to develop diagnostic tests and deliver diagnostic conclusions where possible. After sending off our patient’s laboratory samples, we were told of Mr. X’s rare tick-borne disease.
“A positive POW virus IgM test result was confirmed.
“A virus! Powassan virus.”
She nodded her head to several residents who had befuddled expressions on their faces.
“That’s correct. Powassan virus. You’ve never heard of it. Our patient is the seventy-sixth patient diagnosed with the disease in the last ten years, but the incidence has heightened in the last two years. The numbers are clustered and are ramping up just like we discussed the ramping up the geographical northward expansion and numbers of the white-footed mouse. Don’t forget we had that population boom.”
Dr. Enno reached for the plastic cup of water on the podium and took a sip.
“Many states north and northwest of us have recorded cases, but we now have the distinction of being the first reportable case in Ohio.
“So what is the cure for this potentially catastrophic or fatal disease, which causes inflammation of the brain and/or lining of the brain? What is the treatment for this disease, which can cause mental confusion, seizures, memory loss, and long-term neurologic problems?
“There is no known pharmaceutical drug in our armamentarium to cure or treat Powassan virus!”
A hand shot up from a senior medical student in the front of the room. “Penicillin or doxycycline doesn’t work?”
“No. No such luck since Powassan is a virus, not a bacterium.”
Another arm rose for a question. “The specific tick you mentioned before – Ixodes something – has it been conclusively linked to this particular disease?”
“Ixodes scapularis maintains a life cycle with the white-footed mouse. The answer to your question is ‘yes.’ There are also two types of Powassan or POW viruses. Type 2, also termed Deer Tick virus, is the one associated with Ixodes scapularis. This tick often bites humans. It’s also the primary vector of other human diseases such as Lyme disease.”
Dr. Enno took another sip and sat down on the wooden chair on the stage. She spoke clearly into the microphone.
“Speaking of Lyme disease, however, there’s a big difference between the possibility of acquiring that disease or Powassan. If you find a tick adhered to your body and remove it within the first day or two, you can escape acquiring the spiral-shaped Lyme bacterium because it takes them forty-eight hours to transmit. And we know how awful Lyme disease is.
“However, Powassan goes through the tick’s body into its saliva and into the patient’s bloodstream within a few minutes of a bite. So even though the virus is only present in about four percent of Ixodes scapularis ticks, lower than the 30 to 40 percent presence of Lyme disease bacterium in Ixodes scapularis, if the right tick bores its little head into you, you’re sunk.”
Shania leaned forward.
“These blacklegged deer ticks have a super taste for human flesh and since there is no treatment for POW virus, half of all patients who contract it will suffer permanent brain damage and ten percent will die.”
CHAPTER 31
Dr. Enno stood, gripped Alejandro, and paced across the stage from right to left. Annabel dug into her pocket and pulled out her chocolate-covered blueberries. She sucked on one while she passed a few to Bob.
“Thanks,” he said and smiled.
“I’m so glad you came.”
“I am too. A test and a lecture in one day. I’m tired already, but she’s worth it. She’s so thorough and she hasn’t even brought up my case yet.”
“Did she ask you if she could use your name?” Annabel whispered.
He nodded. “I have no problem with her doing that. Many of the medicine people here are aware that I’m off the wards because of some kind of illness. At least there won’t be a doubt as to my credibility.”
Shania stopped behind the podium after the bit of activity she had afforded herself. She cleared her throat and chuckled. “Making sure my bones don’t freeze up.
“After Powassan virus quickly reached our patient’s brain and held his body hostage, the team kept him alive, we received his diagnosis, and I communicated back and forth with the CDC and local health officials. And above all, we maintained our hope and vigilance for his recovery.
“We are thrilled to report that today our patient not only opened his eyes and is lucid, but his very own medical student extubated him and he will be on his way to recovery. Hopefully, he’ll be out of the unit soon, transferred to a regular room, and engaged with a small dose of physical therapy to gain his strength back.
“Now, many of you are familiar with the tickborne diseases from the newspapers or television or the occasional case we see in our teaching environment. They are more commonly the illnesses caused by infected ticks carrying wretched bacteria such as Rocky Mountain Spotted fever or Lyme disease. But lo and behold, our own medical student, Bob Palmer, had grander plans than acquiring those. He has been recuperating from what’s called Ehrlichiosis.”
She looked straight at Bob and several people in the audience also acknowledged him. Annabel tried not to add to the attention he was receiving.
Shania went to a slide of a tick burrowed into someone’s thigh. “You see this one here. He’s plumper than the one in the picture I showed you before. As they suck blood, they engorge themselves and plump out; they can lose all their physical identity and their forefront can disappear into their host.
“A carpenter can pull a nail out of a wall with the opposite end of a hammer, but a victim of a tick is lucky to root out the vampire from his skin with a tweezer. It’s a death grip to the end.
“And the bacteria they carry? Take your pick: Ehrlichial species of bacteria with Ehrlichiosis, the rickettsia group of bacteria with Rocky Mountain Spotted fever, Borrelia burgdorferi bacteria with Lyme disease and so forth and so on.
“With Ehrlichiosis, our medical student was bitten by the lone star tick, a different tick than that which latched into our ICU patient. Symptoms for this disease include fever, headache, muscle pains, confusion, and low energy. Laboratory clues as to the diagnosis include a remarkable thrombocytopenia, leukopenia, and elevated LFTs. Diagnosis is also confirmed by the detection of antibodies, but you all must recognize that once a suspicion of this diagnosis is made, treatment should not be delayed. The appropriate dosage of Doxycycline for one to two weeks is the magic first line treatment.
“Unfortunately, the case fatality rate of Ehrlichiosis is up to two percent and, like Powassan disease, a patient may need hospitalization and care in an ICU. In this case, IV antibiotics may be needed.”
Shania tapped Alejandro on the wooden floor. “I am happy to report that Dr. Palmer is slowly getting better. Our support goes out to him to get back on track with his rotations.”
Dr. Enno glanced at the wall clock in the back of the room and raised the water cup to her lips. She flipped ahead to another slide, which made the audience cringe more than before - an adult bull dog – his poor body bombarded with plump ticks, some of which were too big to hold on any more and had plummeted to the floor.
“Since we also talk about preventative medicine besides treatment, I would be amiss to not include the measures which we should all take to help prevent tick bites. Part of my sneaky presentation right now is to stir the brain cells of you youngsters in training to do me a favor. In the future, you will be giving your patients the normal pitch to stay healthy with a good diet, exercise, routine medical care, etc., etc.”
She slid to the next slide, which showed a number of items. “Bring up year-round preventive measures with your patients against ticks. Tell families to avoid wooded, brushy areas if there is no need to be there, and to walk in the middle of hiking trails. Tell them about repellents with DEET, and tell them to cover as much of their skin wit
h clothing as possible when they’re outside. There is even pre-treated clothing that repels ticks. Tell them to check for them on their bodies when coming inside and bathe carefully to find them or wash them off.
“Please, treat your family dog with preventive products and don’t let them end up like this fella. They are also susceptible to tickborne diseases and if you don’t treat them preventatively, ticks will be hitching a ride on your four-legged companions and coming into your home.
“Be cognizant of the area around your home. It is possible to apply pesticides in yard areas. Mow lawns frequently, remove leaf and wood clutter so as to not attract rodents, and think about fences, which discourage other unwelcome animals, such as the white-footed mouse that harbor ticks.
“I attest to adding some of these remarks to your patients when you deem it worthwhile and possible. An idiom from my day is ‘An ounce of prevention is worth a pound of cure.’ Alert your patients, especially during yearly wellness visits, of the growing problem with these diseases.”
Shania moved on to another slide. A long list. “My lecture time is up. You may want to jot some of these down but, if not, be aware of the many, many tickborne diseases in the United States besides the ones we dwelt on: Colorado tick fever, Anaplasmosis, Heartland virus, Tularemia, etc., etc. Don’t be afraid to reach out to the CDC in the future and keep up to date with the information that they post.
“Take note of your patient’s symptoms on presentation and never forget how important their social endeavors and recent travels are in the big picture. And remember … ticks aren’t going anywhere, except just about everywhere.”
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Annabel, Bob, and Stuart stepped off the curb into the parking lot.
“I bet that will be the first and last time you’re a subject in a grand rounds lecture.” Stuart raised his eyebrows at Bob.
“I hope that’s true,” Bob said.
“I, for one, am not going to easily forget her talk,” Annabel added.
“Being that our test taking for medicine is over,” Stuart said, “it was better yet to sit back and relax and not have a final exam hanging over our heads.”
