Tuesday, March 18, 2014

New Beginnings: Spring Edition

My life has completely changed since my last post, seven months ago. I wanted to write, in fact, I had a list of topics going for a while, but I just couldn't find a spare hour or two to really iron out the details. In the time since my last post, I got married, traveled to Europe (specifically Paris and London) for my honeymoon, had a birthday, got some new science-specific tattoos, published some papers, was asked to teach a few classes in the fall, took some steps to better myself in my career and my personal life, and got a cat. I have a hard time fitting in time for the gym, or even really breathing!

Here's my husband, on our honeymoon, in a Medical History Museum in Paris (I'll blog about that later). 
I have ideas for new blog posts every day, and I'm going to do my best to start catching up. Be warned, though, my ability to write somewhat blog posts may have decreased, since I've been working on writing three papers simultaneously in the last few months. Maybe you're a distinguished scientist, maybe you're a student, or maybe science is just a hobby to you, but I don't think I need to explain that scientific writing is not the most flavorful of writing styles.

The weather is getting warmer, especially for those of us in California (It was 80 degrees this weekend!). This means gardening, hiking, a general increase in "outdoorsiness". There are two things that I want you to be aware of as you start enjoying the warm weather: Lyme Disease and soil-transmitted parasites! I'll cover soil-transmitted parasites in my next blog post.

One of my dear friends, Kristen, has been trying to dig her heels into some research on Lyme Disease, and I promised I'd post something about it. Since I am stupid, I forgot that I had already written about ticks! Not necessarily Lyme Disease, but a tick-borne virus. Actually, maybe I should try to convince her to write a little guest-blog post for us about what she's learned!? I can imagine myself asking her to do that, and can clearly picture the mixed emotion of extreme excitement and annoyance that would wash over her face. Kristen, if you are reading this, I won't make you do it!

The Tick, via PopGunChaos
Lyme Disease is a bacterial infection that is quite weird, in that you have the ability to be successfully treated with the use of antibiotics within the first few weeks, but it can become chronic if left untreated. Lyme disease has been reported in 80 countries worldwide, and is especially concentrated on the east and west coast of the United states in regions with wooded areas and areas with tall grasses.

Lyme Disease rash variations, via bayarealyme

The bacteria responsible for Lyme Disease is Borrelia burgdorferi, which is a spirochete that has a double membrane, instead of being gram positive or negative. B. burgdorferi is an obligate parasite that uses ticks (Ixodes pacificus) as a vector to infect their mammalian hosts, like rodents, deer and humans. Transmission of B. burgdorferi to smaller mammals doesn't typically result in Lyme Disease (although the rash has been seen in many domesticated dogs that live in rural areas), making that complication specific to human hosts. Ticks transmit B. burgdorferi to humans while taking a blood meal. A simple "bite" doesn't usually do the trick. Transmission is dependent on the length of time the tick has been present on the host (usually 36-48 hours minimum), and on the level of infection within the vector (is the bacteria just in the midgut? or is it present in many different organs, like on the mouth parts and throughout the digestive tract?).

Also, according to samples studied from the Pacific Northwest (California and Oregon), only about 1-1.5% of ticks are infected with B. burgdorferi. With increases in tick populations, the probability of transmission increases. This is one of the reasons warmer seasons lead to more infections.

Ixodes pacificus, via Riekes Nature Blog
Tick size comparison before and after a blood meal, via WA Department of Health
Many studies are trying to determine the proliferation and survival mechanisms of B. burgdorferi because it lacks common pathogenic factors, like lipopolysaccharide, toxins, and specialized secretion systems. Researchers think this may be because B. burgdorferi did not evolve to cause disease in mammals. Not only is there a wide range of variation between bacterial strains of B. burgdorferi, but the analysis of the DNA has shown that it is rapidly evolving.

So why don't you want Lyme Disease? If you are one of the lucky ones that has a resident tick for more than 36 hours, and doesn't identify the symptoms within the first few weeks of infection (meaning you probably wouldn't seek treatment either), then you could experience a wide range of chronic symptoms. Initial symptoms are classic "flu-like" symptoms, such as fever, chills, muscle aches, stiff neck, and just feeling like crap (clinical phrase). To be fair, unless you see a rash with these symptoms, I don't know why you would seek treatment. We've all been sick before, and usually flu-like symptoms aren't severe enough to run to the doctor. A lot of people miss the rash because it's on their scalp/under hair, or somewhere they can't see, like on the back of their neck and trunk areas.

Most people who have chronic Lyme Disease and are being actively treated still feel exhausted all the time. But, without treatment, B. burgdorferi can spread to your brain and heart, resulting in major organ damage and failure. The most common and alarming symptoms are numbness, paralysis, and muscle weakness. It's pretty awful, and you don't want it.

My family has many stories that involve ticks. As you probably know, I am a huge hypochondriac. My poor husband, Peter, has to put up with text messages from me saying things like "AM I HAVING A STROKE?" and "MAYBE ITS CANCER". (Whatever, he knew what he was getting himself into...). I'm also pretty outdoorsy. I'm a runner and love to hike. I hike year-round, but that doesn't stop me from asking Peter to check me for ticks every time I come home from a hike.

My first run in with a tick was in elementary school, on a class hike. My mom, a nurse, was one of the chaperones, and saw it crawling on the back of my neck. I don't remember it actually biting me, but every time we bring that story up, she gets very serious. She hates bugs.

After a hike with my mom, I had the fun opportunity of getting a tick to back out of her skin by using a hot matchstick. She thought it was a mole on her back that was being irritated by her running bra. Sorry mom. Luckily we caught it and she escaped sans Lyme Disease.

Another awesome tick story: my sister is an amazing athlete, and signed up to do her first triathlon a few years ago. She felt sluggish and terrible a few weeks before, was diagnosed with early Lyme Disease despite not seeing a rash (there are diagnostic tests that are done, too), and started treatment immediately. She still competed in the triathlon and finished with a great time. See what I have to live up to? Ugh.