Sunday, April 19, 2015

Get the Rift of it

Last Friday, I was showing some of the work I've done to my fellow Stanford School of Medicine Pediatrics Department-ites, and no one had heard of the virus I've been working with lately, so I decided to turn it into a blog post!

Heyyyyyy.
Since I've only been with my lab for a short time, I started working on a project that wouldn't take a lot of time to complete (you know, to prove myself to my lab -- "look, I've already finished a project!", ha!) before sinking my metaphorical teeth into some more substantial work. Luckily, it's turned into something I can present and publish.

So, let's talk about Rift Valley Fever!

The Great Rift Valley is a massive crack in the earth's crust (a.k.a. - "rift") that basically splits Kenya in two, from north to south. Rumor has it that the Great Rift Valley was discovered by a woman, but no one believed her.

In 1910, Kenya's Rift Valley region started seeing cases of pregnant livestock spontaneously aborting their offspring. This disease was the start of a long history with Rift Valley Fever Virus (RVFV), a Phlebovirus of the Bunyaviridae family. RVFV was eventually identified as a zoonotic agent, infecting people with contact with infected livestock. Mosquitoes were eventually identified as the vector for RVFV when incidence spiked after rainy seasons, as flooding increases potential breeding areas for mosquitoes.

Cows in Kenya - photo from Wildlife Direct
RVFV infections has been restricted to the African continent, primarily in western Africa, with a small outbreak reported in Egypt in 1977. In 2000, an RVFV outbreak was reported in Saudi Arabia and Yemen. The spread is usually a result of trading infected livestock and/or climate conditions that support the migration of mosquito populations.


RVFV is an enveloped, single-stranded RNA virus. The RVFV genome is divided into 3 segments of differing sizes (small, medium, and large), all of which are circularized. Host cells targeted during infection include macrophages, hepatocytes, and endothelial cells.

A computer modeled 3D structure of RVFV - image from Dr. Juha Huiskonen
Pathophysiology of RVFV in humans includes the standard headache, high fever, weakness, back pain, fatigue, and dizziness. Most people with these flu-like symptoms recover in about a week, and that's it. In severe cases, though, patients can develop encephalitis, retinitis, and hemorrhagic fever.

Given the severe affects on livestock reproductive viability, RVFV outbreaks can have devastating affects on the economy. Not only can you lose a large amount of your livestock population through death of the infected animal, and future generations by abortion, but once infected animals are identified, you are banned from trading livestock for an extended period of time. This process has been very effective in containing RVFV to the continent, but not all infected animals present symptoms prior to trade or breeding. With a large enough outbreak, severe economic collapse could follow.
An unfortunate casualty - Image from The Travel Doctor
There is a vaccine available to herders, but it can also cause the vaccinated animal to spontaneously abort developing offspring, although at a lower rate. Yet, it's difficult to convince herders to vaccinate their animals if they are (maybe) damned if they do and (likely) damned if they don't. There are also models that have successfully predicted RVFV outbreaks in the past.

The United States Department of Agriculture (USDA) has listed RVFV as a major threat to the U.S. because of the large economic dependency we have on livestock. Even though the virus has only started to leave Africa, the U.S. does have the vectors to support spread to North America.

Saturday, March 21, 2015

Taenia solium and the leaky brain cyst

For my other blog (warning: not a scientific blog), I wrote a little thing about why Spring is one of my favorite seasons (I mean, second to Autumn of course!) because it brings an abundance of cute baby animals to the world. One of my absolute favorites is the pig! Domesticated, wild, big, small, it doesn't matter.

Image from Daily Mail.
So, in honor of all the piglets being born this season, let's talk about a classic parasite with some new research twists. Taenia solium is a type of tapeworm that is specifically linked to pigs. T. solium is related to the "beef tapeworm of man" (Taenia saginatum, tapeworm associated with cows), but can cause some much more severe symptoms.

T. saginatum scolex imaged using electron microscopy. Image taken from the internet.
T. saginatum, the beef worm, is what everyone thinks of when they think "tapeworm": adult worms have a head, neck, and proglottids, and causes intestinal obstruction and discomfort. Oh, and it can live inside of you for up to 25 years!

In order to get your own tapeworm infection, all you have to do is consume poorly cooked beef which contains T. saginatum eggs. When the eggs "hatch", oncospheres (infective larva) migrate to the small intestine, where they will take 3 months to mature into an adult worm. Adult worms are typically 2 to 10 meters in length. Usually only one worm is found, unless you've consumed a heavily contaminated piece of meat or ate fecal matter that's full of gravid proglottids (the end pieces of the tapeworm). Fun fact: eggs can survive for months once they've left the body. Beware of old poop!

Taeniasis life cycle for T. saginatum and T. solium, via the CDC

Patients infected with a beef tapeworm (clinically described as "Taeniasis") may complain of non-specific abdominal symptoms, such as nausea, general pain and discomfort, or weight fluctuations. I say weight fluctuations because most people experience extreme weight loss (often misdiagnosed as anorexia), especially those affected in developing countries (where these parasites are most prevalent), but there have been a number of people who have infected themselves, by choice, and have reported it being "no big deal" or that they gained weight (see my favorite example: Michael Mosley of the BBC News). So, while most people experience weight loss, I suppose you could say that depends on your socioeconomic status, and whether or not you've had a choice to become infected.

T. solium life cycle from the Food and Agriculture Organization of the United Nations (fao.org)
T. solium can also cause all the same intestinal symptoms, and can live out a life cycle similar to that of T. saginatum. But, in some cases, T. solium can cause something called Neurocysticercosis (cue scary music). T. solium's life cycle and pathophysiology usually looks very similar to that of T. saginatum, only with smaller worms (4-7 meters in length). Neurocysticercosis occurs when you've ingested the eggs directly, such as ingesting contaminated feces. This happens to pigs when their food is contaminated with human feces (pretty ironic, right?).

T. solium scolex. Image from UNAM.
The consumed eggs hatch in the small intestines and the oncospheres are released. Oncospheres penetrate the intestinal mucosa and make their way to the blood. Once in the blood, they travel throughout the body and migrate to different tissues, where they will mature into cysticeri. The cysticeri really like skeletal and cardiac muscle, subcutaneous tissue, and lungs, but they can also get lodged in the central nervous system (CNS), including the brain and the cerebral ventricles. Once the cysticeri have chosen a tissue which to lodge themselves, they become calcified granulomas.


T. solium adhering to the epithelial cells of the intestine. Image from UNAM.
The most common location for cysticercosis to occur is the cerebral hemispheres, at the gray-white matter junction, but they can also be found in the cerebellum, the brainstem, the subarachnoid space, the basal cisterns, and the spine.

T. solium cysts in a human brain. Image from Discover Magazine.
 Obviously, having a 1-2 cm cyst calcifying in your brain will cause some damage. Neurocysticercosis is one of the leading causes of epilepsy in developing countries. It can also cause severe headaches, hydrocephaly and eosinophilic meningitis.

The National Institute of Allergy and Infectious Disease (NIAID) just released an article about the treatment-induced inflammatory response in pigs with neurocysticercosis. The current treatment of Praziquantel is apparently causing inflammation, blood vessel leakage, and damage to the blood-brain barrier. This means that new drugs need to be developed that can reduce inflammation at the site of the cyst(s) while maintaining the integrity and functionality of the blood-brain barrier and blood vessels.

Photo of the surface of the brain of a pig treated with the antiparasitic drug praziquantel showing blue-dyed (blue arrows) and clear (white arrows) cysts. The blue dye indicates disruptions in the blood-brain barrier. Image from NIAID/
Dr. Cristina Guerra-Giraldez.
This research only focuses on pig subjects, and has not yet been performed on humans infected with neurocysticercosis.


Want to avoid tapeworms and neurocysticercosis? The best way to do that is either to avoid eating meat, or to make sure your meat is cooked properly. Cooking meat properly is the best way to inactivate or kill most infectious diseases associated with meat consumption.

One of the major reasons diseases are so rampant in livestock is because a lot of treatments (mainly antibiotics) are used as prophylactics instead of at the onset of infection and symptom presentation. Animals that are raised in small, confined areas are more likely to be exposed to illnesses. When you are raising animals on a large scale and rely on them for income (whether through livestock trade, meat or dairy production), it can be really scary when one of your animals gets an infection, because you risk losing some of your income. It's obviously unethical to sell/trade sick animals, but it happens all the time, and is one of the main causes for the spread of disease to other regions. When prophylactic treatments are used, resistant infections are more likely to occur, which is an even larger problem (as I'm sure you can imagine).

Even if the meat you consume came from a healthy cow/pig/lamb/goat/chicken/turkey/etc., it might have been slaughtered in the same environment as a sick animal, which still puts you at risk. So, if you have a tendency to order your meat "rare", be sure you know the risks associated with that choice.

Edited to add:
I want to be clear that, even though I'm vegan, I believe choosing to be vegan is a very personal choice and no one should ever be bullied in to it. But, I also feel the need to add some information about the environmental impacts of eating meat to this post, since we are talking about risks associated with consuming meat. Considering the risks to yourself is very important, so you can actively minimize your risk of getting an infection or other serious health disparity (mostly through the long-term, excessive meat consumption),  but considering the long-term risks for the environment (ie- everyone on earth) is also really important. Here are some articles that you might want to consider reading before making a definitive decision about your dietary habits:

The Triple Whopper Environmental Impact of Global Meat Production: TIME

How does meat in the diet take an environmental toll?: Scientific American

Giving up beef will reduce carbon footprint more than cars, says expert: The Guardian

2500 gallons all wet?: EarthSave


Saturday, February 28, 2015

Toxoplasmosis

I was inspired to write this entry because I have a number of friends who have recently crossed over into that place in your life where you suddenly want tons of kids. Some of them have just recently birthed their first child (congrats to you), and some are just starting to feel that warm glow of constant nausea that will stick with them for the next few months. This is an awkward time for me, personally, because I fall into the category of "never, no, not interested" when it comes to babies. I've always kind of been that way, and yes, I fully acknowledge that my feelings could change in the future. I also want to point out that it would be fine if my feelings didn't change, because it's not an obligation that all women have (to have children, that is). I should also say that I like kids, and I think that they are amazing little creatures.

I wanted to bring this up for two reasons:
1. being pregnant has to do with the parasite I'm going to discuss later in this post, and
2. the Washington Post published an article about Eugenie Clark, who just passed away on Wednesday. The article is a great little summary of her life, but this is one of the most important parts (in my opinion):
"Professors at Columbia University told her it would be a waste of their time to admit her to their graduate program because she’d end up as a housewife..."
 Granted, this was in the 50s, but it struck me to see that so boldly stated. I've had mentors make comments like that to me within the last FIVE YEARS. While it's really important to state that women like Eugenie Clark have paved the way for women scientists, we still have a lot of work to do. I've had a lot of really incredible mentors, but it's hard to move past comments that one or two bad apples may have made, especially in such early and exploratory years of my career. If we strip away all the statistics about women and minority populations in science/STEM, we can still come to the same conclusion about comments that assumingly discourage someone from doing what they want to do with their lives: it's mean. It's really mean to do that to another human being, no matter what population they do or do not fit into.

I know that was more into my personal life that I usually divulge, but that article really inspired me.

So, back to my friends and their pregnancies!
A majority of my friends that are getting pregnant/having babies also have cats. I know, I know, you know where I'm going with this because its old news and everyone should already know about it. Well, not everyone does.

Toxoplasma gondii. Image from National Geographic.

Toxoplasma gondii is a parasite that can infect all warm-blooded animals and birds (as intermediate hosts), but is primarily centered around the definitive host: cats. Actually, over 200 mammalian species can act as an intermediate host for T. gondii, which makes the prevalence in humans pretty high.

As you can see below in this terrifyingly hilarious life cycle image (thanks, internet), the life cycle of T. gondii (sexual development) is completed in the intestines of a cat (even if it is a cross-eyed Halloween caricature of a cat like the one in this image).

Image discovered somewhere online, although I couldn't find a clear source which to give credit. Sorry.
Infection in humans is usually asymptomatic, meaning a non-infective (dormant, non-pathogenic) stage of T. gondii could be in you right now, and for most of your life without you even knowing! Most infections are triggered by a state of immunodeficiency. There have been some studies that have looked at the possible correlation between T. gondii infection and schizophrenia (a few years ago, you may have seen a bunch of sarcastic articles about how your cat is trying to control your mind, etc.). If you do develop acute Toxoplasmosis, you'll usually only experience non-specific symptoms, such as malaise, fever, and other flu-like symptoms that can resolve themselves within a few weeks or months. A lot of times, Toxoplasmosis isn't diagnosed correctly because proper diagnosis is really dependent on the organ system that is infected (heart, eyes, brain, etc.), and depends on the pathology lab to identify the organism in your tissue samples.

The biggest issue with Toxoplasmosis comes when you are pregnant, because it can cause spontaneous abortion, or if you carry to term, can be passed congenitally causing hydrocephaly, mental retardation, cerebral calcification, and chorioretinitis.

If you are pregnant and have an indoor/outdoor cat that uses a litter box in your house, I'd suggest avoiding any contact with it for the time being. You can be exposed to infectious fecal particles while emptying the litter box, that can be ingested accidentally. I'm not really sure why you wouldn't wash your hands thoroughly after handling an animals wastes, but that might be another thing you'd want to start doing, especially now that you are pregnant and all.

 Another fun thing about T. gondii is that you can become infected through organ transplantation! Organ recipients can get Toxoplasmosis from the new organ, or from self-activation (if you've already been infected with a dormant, non-pathogenic stage, but go into immunodeficiency after surgery). This is pretty rare, but it is possible.


Here's a picture of my cat, Milo (aka "Beef"), who usually helps me write these blog posts, and made it known that she does not appreciate this particular entry.

Sunday, January 25, 2015

A two'fer

January: the peak of flu season, the aftermath of the holidays, and my birthday month. To celebrate all of those things, you get a two'fer today. Two subjects, one post.

Before I dive in to my two topics for today, I wanted to remind you that the Ebola outbreak is, unfortunately, still going strong. Just because the news no longer finds it new, doesn't mean it's over. Just because someone made "Ebola patient" Halloween costumes and oh, Halloween was so long ago, doesn't mean it's over (also, you should be ashamed of yourself if you donned that, or any version of that costume). As of yesterday, the outbreak has killed more than 8,600 people. I encourage you to stay informed via the Ebola Map.

Anyway...back to our regularly scheduled program:

Let's play GUESS THE DISEASE!

In 1757, a Scottish physician by the name of Francis Home proved that ___________ was caused by an infectious agent in the blood of afflicted patients.

In 1912, __________ became a "nationally notifiable" disease in the US, meaning that all health care workers were required to report all cases, as approximately 6,000 deaths were caused by _________ per year.

In the 1950s, nearly all children got __________ by the time they were fifteen years of age, causing scientists and the federal government scrambling to find a solution. In 1963, a vaccine was finally available. Thanks to the development and approval of the vaccine, the US government aimed to eradicate _________  by 1982. While this didn't completely happen, cases were decreased by 80% from 1980 to 1981.

In 2000, _________ was declared eliminated in the US.

Have you figured it out yet? Better yet, have you caught it, yet? (haha I'm so funny)

Still stumped? Here's one last hint:

Photo courtesy of the Centers for Disease Control and Prevention
It's Measles! The famous Morbillivirus is back in a big way, and is running rampant at one of the happiest places on earth. Measles (or Rubeola) is a highly contagious negative-sense single strand RNA virus of the paramyxoviridae family that is illustrated by symptoms in the respiratory tract, skin, and immune system. The obvious rash (seen above) is often accompanied by a hacking cough, Koplik's spots, red eyes, and high fever. Measles is an airborne virus and is dependent on aerosolization (coughing, sneezing) in order to spread properly. The virus can "live" in aerosolized droplets for up to two hours on a surface. Assuming there are no complications, measles usually runs its course in about 7 to 10 days (like a gross case of the flu).

So, why do we care? Why was the US government in a rush to eradicate such a disease?

Measles is really prominent in children, and children usually don't have an immune system that can withstand stubborn viruses with a history. A lot of children (actually one out of every 20 kids infected) end up developing pneumonia as a result of a measles infection, which is actually the leading cause of death from measles in young children. About one out of every 1,000 children that are exposed to measles can develop encephalitis, which can cause permanent brain damage due to excess swelling. Ear infections associated with measles (affecting 10% of infected kids) can result in permanent hearing loss.

It's estimated that over 16 million people visit Disneyland every year, with attendance fluctuations based on holidays and common school schedules (like summer break). That's almost 45,000 people PER DAY in a place were everyone is touching everything from handrails to harnesses, from interactive displays to the bric-a-brac in all of the shops.

In the latest measles outbreak, that officials are saying started at Disneyland, a handful of employees were also infected. I bet a lot of those employees were vaccinated as children, but since Disney hires people from around the world (I say this as a fact that I applaud because everyone should be able to live out their dream of working at Disneyland... and because I desperately want to be Maleficent), I bet a good chunk of their employees didn't grow up in areas that enforce strict vaccination requirements for school-aged kids. Vaccination requirements vary by state, by country, and some are better enforced than others. Plus, school-based vaccination requirements don't usually include home-schooled kids.

I'm not going to launch into some diatribe on how I feel about vaccinations (I'm sure you know already if you read my blog regularly), but I will say that the MMR vaccine (that's Measles, Mumps, and Rubella in a combination vaccine) has lead to a 99% reduction in infections, compared to the pre-vaccine era (prior to 1963). If you aren't sure about your vaccine history, I heavily encourage you to go get an Antibody Titer Test done. A titer will tell you what antibodies you have the ability to produce, whether from vaccines or direct exposure, and will tell you which ones your body isn't able to currently make, meaning you haven't been exposed, or you need an additional vaccination or booster. Not only could this simple test save your life, but it could also save the lives of others that may not be able to fight off diseases. If you're vaccinated, it's like saying "Hey disease! You'll have to get through me first before you can infect this baby, that old lady, or that person with a compromised immune system. OH WAIT, YOU CAN'T!"...and suddenly you're a hero.


I also want to remind you that its not just Disneyland, and its not just measles. Think about how many people you encounter every day, and how many people your family members encounter. Who knows what you've touched! I take the bus every day to work, and I can't tell if it's making my immune system stronger, or taking years off of my life.



Speaking of taking the bus, here's your second subject!!

I've been reading a lot since I've started taking the bus to work. I mean, reading for fun. This is the first time in probably 20 years that I've really had time to read for fun, to read for ME, and I love it. In fact, I've already finished my first book of the year, and while it wasn't science-related, there were some topics that really interested me.

The book I just recently finished (because I seriously couldn't put it down) was Unbroken by Laura Hillenbrand, which details the life of Louis Zamperini and his experiences during World War II. It is heartbreaking and amazing. I cried multiple times on the bus while reading this book (what, Zamperini reminded me a lot of my late grandfather, so it was extra emotional for me).

I won't spoil the book, but there are a number of chapters that talk about the life of American and Allied men that were caught and held as POWs in Japan. One of the most prominent health issues that was seen in these camps was beriberi. Beriberi is an illness that occurs as a result of severe thiamine (vitamin B1) deficiency, without infectious agent, and presents in two ways: wet beriberi and dry beriberi.

Wet beriberi affects the cardiovascular system, causing shortness of breath, increased heart rate, and swelling of lower extremities. Dry beriberi, or Wernicke-Korsakoff syndrome, affects the nervous system, and can cause loss of feeling, paralysis, difficulty walking, mental confusion, strange eye movements, pain and vomiting. Both wet and dry beriberi can become severe very quickly, and can lead to permanent damage and death.

Thiamine deficiency is common in developing countries, especially regions with restricted access to food due to war, severe economic conditions, and environmental conditions that make it difficult to grow or access food. I bring this up because it's easy to read a book like Unbroken, and think about beriberi as an issue that only hurt POWs during WWII, because you stop hearing about it once you finish the book. I encourage you, as you read books or whatever you're looking a online, to do further research and teach yourself something new. LeVar Burton would be proud of you.

Monday, December 1, 2014

World AIDS Day 2014

World AIDS Day 2014 Poster from CDC.gov
This morning I scrolled through the last few years of entries on this blog, looking for a World AIDS Day post to which to link. I then realized that I am lazy and less empowered than my younger self. My whole world used to be consumed by HIV, so to speak.

While in high school, I learned that one of my most honored relatives was HIV positive, and I instantly changed my path to learn everything about the unknown. They didn't stress how scary this virus can be, and usually is, while I was young. It was a monster from the 80s that wasn't scary anymore, which is entirely inaccurate (well, not the 80s part). All of the sudden, someone I knew had been infected, and by the time I went to college, that number had exploded.

I ran the free HIV testing clinic in college, and advocated for a better educated, a more empowered sexually active youth culture. I volunteered and then later worked for Planned Parenthood, and supported every client without judgement. As a health educator, I taught college freshman, whom had never had any exposure to sex ed, about the basics: everything from basic anatomy, dispelling menstruation myth, STIs, etc. I even researched HIV for my graduate thesis. There was a time in my life where I felt like I was talking about HIV every day. But people still weren't concerned.

New statistics show that only 4 out of 10 people in the US who are infected in HIV in 2011 were receiving HIV-specific medical care (meaning regular monitoring, access to medication, viral suppression, etc.). Approximately 3 in 10 people with HIV in the US had achieved viral suppression, which is a critical factor in continuing to live and thrive with the infection. According to the CDC, 76% of people who receive HIV medical care achieve viral suppression. That means 46% (yes, almost half) of people with HIV in the US either don't have access to adequate care, don't know about it, don't know that they have HIV, or are refusing care. I shouldn't have to point out that these are only statistics for the US, and access to care on a global scale is much worse. 

via CDC.gov


Now that I've made my way back into my field (after my 3 year stint with NASA),  I find myself getting really frustrated and feeling really helpless about HIV. It wasn't until this year that I realized how distanced I've become. Honestly, I'm a little embarrassed, because this is such an important topic for me.

So, I'm going to strive to reinvent my commitment to advocating for patients, for access to care, for continued funding, and for access to real education. We need to be frank about this subject, because it's not going away anytime soon. As far as I'm concerned, we probably wont find a cure within the next 10 years (as some people are claiming), and even if we do, the focus needs to shift to continuing to support those who are infected, and those who are at risk of becoming infected.

Even though World AIDS Day is coming to an end for this year, make it a point to start talking about HIV, and get empowered to get tested regularly. Use the resources that are available in your community, and learn how you can protect yourself. AIDS is everywhere, and we need to stop pretending that it's a thing of the past.



Tuesday, November 25, 2014

2014 Outbreaks: Plague Edition

This is the time of year where you are supposed to feel thankful for all the things you have in your life, whether its family, friends, stability, purpose, faith, or maybe even physical things. But, honestly, this year has been hard to feel truly thankful, scientifically speaking. There's been a lot of distrust, a lot of fear-mongering, and a lot of really terrible journalism that has made people (primarily Americans) really hate any scientist (or doctor, or medical professional) that isn't Neil DeGrasse Tyson. But guess what: we aren't lying to you, and we are doing the best we can to figure things out thoroughly and efficiently. Funding is at an all time low, support for major research is very political, and there is a surplus of newly graduated PhDs that aren't being utilized. Science is simultaneously really hard and really amazing right now.

Now that I've said all that, we can focus on what's happening right now in science: the plague.


You may remember learning about the bubonic plague in middle school, when your history classes were covering the middle ages, and it was the perfect time to talk about disease in science class (because let's face it, the middle ages were gross). I'm guessing you learned about it and immediately let yourself forget about it because you figured "well, that's over and done with so I'm safe."

Surprise! Approximately 40 people have died from the plague in Madagascar this month, and there have been approximately 120 cases reported.

But, look, this isn't shocking. In 2012, I even wrote about how there was a confirmed plague case in a rodent in Los Angeles. But, it is shocking in the sense that we haven't seen anything near "outbreak" proportions since the middle ages (and you have public health to thank for a majority of that!).

Yersinia pestis, the bacteria that causes the plague, is most often (not really often, per say) seen in animals, and is rarely transmitted to humans anymore. The middle ages were different, though. Animals (and fleas!) lived in very close quarters with families. Since hygiene wasn't really a fad yet, diseases like the plague would spread incredibly rapidly. In some countries, 50% of the population was wiped out.


There are three different forms/presentations of the plague:
  • Bubonic plague, which is transmitted by fleas and causes bulbous swelling ("buboes") around the lymph nodes
  • Pneumonic plague, which is respiratory, and spreads between humans via aerosolization and contact with fluids
  •  Septicemic plague, which is an infection of the blood
The bubonic plague can be treated with antibiotics, but pneumonic plague is incredibly deadly. In some incredibly severe cases, it can kill you after only 1 day of infection (not including the incubation period).
I am particularly nostalgic for the plague because it was the first real disease that caught my attention. Not only do I remember becoming completely infatuated with diseases, but I still have the report I wrote about the plague in 7th grade. Maybe if you really hope for it, I'll scan it and post it for you to laugh at. Tis the season for miracles, after all... right?

So, while you are sitting around, eating ridiculous amounts of food, try to be thankful for the advancements that have been made in science and health. If you have access to potable water and a waste treatment system, then you should be extra thankful. If you've had access to education, whether you've taken advantage of it or not (no judgement either way), then be overjoyed. Think of all the things that have changed since the middle ages, and be thankful.


Sunday, November 2, 2014

Secret Benefits to Thalassemia, Round 2: Email Inquiry

I get emails from people asking for me to diagnose them based on images of maggots that they found on their skin, a peculiar rash they've had for years, or something they found in their poop. I have to say, I love these emails. If anyone is worried about the NSA spying on their email activity, it should probably be me, because my inbox is full of stuff that could be considered private medical information, and I am not an MD.

But sometimes I get legitimate questions, like this one that I featured on my blog forever ago (don't worry, I always ask if they mind if I post their questions). Recently, I got a really interesting and smart question from an anonymous reader. The email said:
Dear Doc,  is there an immunity of reduction of Ebola with people who have beta-thalassemia? Or is it just the opposite, a more susceptible case for those with beta-thalassemia?
If you don't remember what beta-thalassemia is, or why it might be "beneficial" (I say this loosely, as it's not necessarily a good thing to have), feel free to brush up by reading this old post about it and it's relationship with malaria.

Image from the American Society of Hematology
To recap, thalassemia is a disease associated with globin gene mutations (both α- and β-globin genes can be mutated, yet α-globin mutations are most common). Since your α- or β-globin gene is recessively mutated if you have active Thalassemia, your red blood cells develop into malformed, or "sickled", cells, thus inhibiting their affinity to bind and transport oxygen (see image above for a great example). This lower affinity can cause extreme cases of anemia. In major cases, treatments such as chronic blood transfusion therapy, splenectomy, transplantation and iron supplementation are used. Thalassemia would make a great potential candidate for genome editing therapies that are still in the research stage (yes, I know that article is about hemophilia, but it's a good example).

So, why is this anonymous question a great one? Simply put, it doesn't really have an answer. There isn't any research being done to look into populations that aren't as affected by Ebola right now, as far as my searches have illustrated. This might be because most research that's being done is to either understand the physiology of the virus, to identify all possible vectors (yes, most evidence point to bats as the vector, but I'm still not convinced), or to come up with therapies/treatments and vaccines.

But the submitted question addresses an important point: thalassemia, specifically β-thalassemia is really prevalent in Nigeria (25% of the population are carriers for Sickle Cell Disease, while another 25% is hemizygous for the G6PD gene), and other parts of Africa. So, why isn't this being looked into? I can't answer that. I don't know. All I can say is maybe it isn't yet. I'm sure now that Ebola is in the spotlight, there will be a new emphasis on funding down the line for exploratory research.

In my fervent literature search to find an answer for the anonymous email, I did find that similar research has been done to look at the effects of thalassemia on hemorrhagic fevers (specifically Dengue Hemorrhagic Fever), mostly in Thailand and Southeast Asian countries. It turns out that patients with thalassemia don't necessarily have any higher risk, or even less of a risk (as seen with malaria), of getting hemorrhagic fevers, as my anonymous email inquiry asked. But, they do present differently, meaning their symptoms may seem different than infected people without thalassemia. Most normal (non-thalassemia) patients show signs of hemoconcentration (or an increase of solids in the blood), but patients with thalassemia present anemia (which is the opposite). This is the main symptom that presents differently, but its a really important one. Other symptoms also reference changes in AST and ALT levels, which illustrate the concentration of enzyme in the liver, heart and muscle cells, and can indicate liver function.

Hemoconcentration is really important during the diagnostic phase, and to track how the infection is progressing. So, if, instead, your patient is presenting with the exact opposite, it might lead to misdiagnosis. Also, if a patient with thalassemia, who is also infected with dengue hemorrhagic fever, is showing anemia, it needs to be watched. The three papers I linked to above talk about new suggested courses of action for patients with thalassemia, like frequent blood transfusions.

So, anonymous emailer, the answer is probably not. The biggest risk that thalassemia would give you is misrepresenting symptoms, which can lead to improper care. Yes, that can be really dangerous, especially with hemorrhagic fevers. But, luckily, if you have a high fever and other viral (standard) infection symptoms, your doctor will usually run other diagnostic tests (like an ELISA or PCR, etc.). That's why they always ask you questions about where you've been, what you've been in contact with, and other patient history questions.

This is definitely research that should be done, even if it starts with a retroactive epidemiology study.

Thanks for your question!

If any of you have other questions, feel free to email me at microscopic.blog@gmail.com!