Tuesday, February 7, 2012

Hearts A'flutter with Infection

I admit, I'm a total sucker for Valentine's Day. I'm pretty sure this has something to do with my childhood, since my mother's favorite holiday is Valentine's Day. She made it her mission to make Valentine's Day as big as Easter, right down to getting festive baskets full of heart-shaped candies and whatnot.

What I also love about it is the imagery. It's the one day of the year when mainstream culture romantically fetishizes an internal organ! How sexy is that?

Did you know that in one day, the force of your heart pumping causes your blood to travel approximately 12,000 miles? That's four times the distance across the United States, from one coast to the other.

The heart is an amazing organ. It's, quite literally, the lifeblood of your existence, pumping nutrients and oxygen to every bit of your body, working with the lymphatic system to circulate immune system cells, keeping you alert. But the heart is also a vulnerable place. Although we mostly hear about parasites of the GI tract, there are many other organisms that see our circulatory system as an all-you-can-eat buffet.

If you think about it, the circulatory system and heart provide the perfect environment: tons of nutrients (see: snacks), tons of oxygen, a comfortable temperature (like a sauna full of blood) and hardly any competition.Who wouldn't like that?

Since this is a post for Valentine's Day, I'd like to tell you about the best of the best. Please keep in mind that there are thousands of things that can find their way to your heart and eat you inside out. These are just some of the highlights.

Protozoan parasites:
Leishmaniasis is typically seen to affect the spleen, liver and bone marrow during a visceral infection (as opposed to the cutaneous infection that causes lesions and boils), but it can also find it's way to your heart and cause damage there. There are about 500,000 new cases of visceral leishmaniasis every year, but they are all dependent on the local sand fly population, which acts as the vector for the disease.

Visceral leishmaniasis results in the inflammation of the infected organs. If not treated, the swollen organs may become non-functioning, which can result in organ failure and death.

T. cruzi, the cause of Chagas Disease, has shown high cardiotropism that is unmatched by other parasitic organisms. This flaggelated protozoa has the ability to "swim" or move throughout your system.

Not a sea slug, but just as cute?
Once settled in a comfortable area (filling the void of your broken heart), your heart will begin to swell with the inflammatory response. After trying to kill off the invading organisms, cellular damage and fibrosis occurs, making the likelihood of heart failure very high.

This is your heart on Chagas Disease.

Worms and things:
Schistosomiasis, also known as Snail Fever, is a parasitic worm that causes a chronic condition in adults, and impairs cognitive development in children. Early stages of Schistosoma development, the immature worm feeds on red blood cells. While it mostly affects the liver, the worms occasionally can get turned around and burrow into the heart tissue. Schistosomiasis has a very low mortality rate, but is very devastating. 

D. immitis is the very well known "Heartworm". We mostly hear about heartworms in our pets, but they can definitely infest humans, albeit rarely. The heartworm doesn't become an adult until it has settled into the pulmonary artery. Before that, it's transmitted from host to host by it's vector, the mosquito.

Dog heart.

Echinococcosis happens to be one of my most favorite parasites. Echinococcosis infects mostly mammals, including humans, and is transmitted directly through the accidental consumption of a cyst or egg form. While mostly found in the liver, up to 25% of cases are found in organs like the heart, brain, kidneys and less commonly, lungs. But this worm is special. Echinococcosis is also known as hydatid disease, from the formation of hydatid cysts.

Hydatid cyst, single and ready to mingle.

The worm develops it's eggs into a collection of "egg sacs" or bubbles within a tissue. These sacs have multiple compartments of eggs, and have the ability to grow very large and very numerous. They are strong enough to survive the host's environment, but delicate enough to be very tricky to remove during surgery. If a cyst bursts, the patient can go into anaphylactic shock (similar to an appendix bursting).

On a sappy note, I started this blog almost 2 years ago because I needed an outlet. I was talking too much about the dangers of the world. My friends and family were tired of hearing about my research or the latest in disgusting discoveries (and still, my dad seems to be the biggest fan of my blog!). Even worse, I was ruining dates! You can always tell how the rest of the date is going to go when you mention that you may have been handling active HIV earlier that day in your lab, or you have volunteered your time to look at poop samples from the county. My favorite was the date that said, "I mean, I like nerdy girls, but I kinda just meant girls in glasses."

As of now, I'm miles ahead of where I was 2 years ago, both in my career and my life in general. To be honest, I never really thought that my life would involve any sort of writing, other than the to-the-point articles of my great discoveries in science (I say, as if I'm Marie Curie or Barbara McClintock). What I'm trying to get at with this uninteresting rant is THANK YOU, dear readers, for taking an interest in my low-bar jokes and nasty photos. I hope this blog has, and will continue to, help you as much as it has helped me.

Happy Valentine's Day!

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