Saturday, November 11, 2017

Cats, Bats, and Rats: Harbingers of Diseases of Disparity

On Monday, I attended a symposium, titled "One Health: Interface of Human Health/Animal Diseases", at the American Society for Tropical Medicine and Hygiene (ASTMH) annual meeting (aka #TropMed17). This was one of many sessions I attended, but one of the few that really stood out to me.

I love the concept of One Health, which emphasizes the interwoven nature of the environment, animals, and humans, where a change to one aspect of the world will affect the other surrounding environments and populations. This is a vital concept when it comes to global health, as we often focus on human disparities without working to improve the person's environment for sustainable health and change. As you can imagine, One Health is a critical component when describing the lifecycles of zoonotic diseases, which infect both animals and humans. I wrote a magazine article for The Biochemist about the impacts of One Health on disease emergence. You can find that here (e-zine) or here (PDF), for free.

Within the One Health symposium, each speaker outlined an important animal exposure for each infection, whether parasitic, viral, or bacterial. For example, the first speaker discussed an outbreak of hantavirus in Peru during the creation of a new interoceanic highway that runs across Peru and Brazil. Deforestation and construction created a new opportunity for exposure to hantavirus for construction workers and residents in the area. Here's some more info on that, if you are interested.

Image of bats emerging from the Swedagon Pagoda in Myanmar, borrowed from an article on Biodiversity via ResearchGate
Another speaker spoke about emerging pathogens in Myanmar due to exposure to bats through the use of caves for economic (mostly the creation of tours for tourists) or religions purposes (think shrines in caves). Myanmar apparently has 22% of world's species of bats, meaning it has a diverse population of bats, and they are everywhere.

The two talks that I really enjoyed covered parasitic infections that are a global issue affecting primarily low income populations, even those in the United States.

Beautiful illustration borrowed from The New Yorker
Angiostrongylus cantonensis, or "rat lungworm", is a parasitic nematode that is found throughout Southeast Asia and the Pacific basin. Rat lungworm causes eosinophilic meningitis in humans. Humans are exposed to A. cantonensis through ingestion of infested foods, like undercooked or seafood, fish, frogs, vegetables, or snails.

An apple snail, image borrowed from Hidden History
 Apple snails act as a reservoir for A. cantonensis throughout Southeast Asia. Upon investigation, the larval stage of the nematode can be found invading the lungs of the snail. Adult A. cantonensis live in the pulmonary arteries of rats, and larvae migrate to the pharynx, where they are swallowed by the rat and dispelled in the rat's feces. The larvae are then ingested by the apple snail, or other specific mollusk species.

The apple snail can be purchased to eat from stands along the road in Laos, Cambodia, and Thailand, or the larvae can infest other aquatic animals. Once ingested by a human, the nematode travels to the brain through the blood stream, and then dies shortly after. The presence of a foreign body in the central nervous system causes a flood of white blood cells, specifically eosinophils, which triggers inflammation of the meninges. While this can clear on its own, some people have been seen with significant neurological dysfunction, some of which are lifelong, or death. This parasite is most commonly associated with Southeast Asia, in the past few years, has popped up in Hawaii.

Another speaker detailed a project focusing on parasitic load in public parks throughout New York. Toxocara spp. can infect dogs (Toxocara canis) and cats (Toxocara cati), and can also infect humans if the eggs are ingested. I think a lot of people in the US believe that parasites are a problem in other countries, but there are many types of parasites that can infect (and infest) people in urban and rural areas of the US.

Toxocara roundworm image from the CDC
Toxocaraisis, or an infection caused by Toxocara spp., is a roundworm infection that causes symptoms depending on where the larvae migrate in the body. Visceral toxocariasis occurs when the larvae migrate to various organs, most commonly the liver or central nervous system, causing fever, fatigue, coughing or wheezing, or abdominal pain. When in the central nervous system, psychological symptoms and neurological dysfunction can occur. Ocular toxocariasis occurs when the larvae migrate to the eye, causing symptoms relating to the eye, such as vision loss, inflammation of the ocular tissues, or damage to the retina that can cause permanent blindness. The CDC estimates that up to 70 people are blinded each year from Toxocariasis. Many people clear a Toxocara infection without experiencing any symptoms, and have a strong immune response.

This particular project tested soil and sand samples from parks because children are frequently exposed by ingesting soil and sand from parks, and from putting contaminated hands in their mouths. Infection during childhood can affect childhood development, and most people are never diagnosed if they don't present with severe symptoms. Many psychological symptoms aren't linked to parasitic infection, so they aren't treated appropriately!

Some random kid from the internet eating dirt.
More importantly, the presenter emphasized how this is an infection that is more common in low income communities. For example, out of all the areas tested throughout New York, parks in the Bronx had significantly high contamination levels (something like 67% of parks tested in the Bronx had positive samples!). The CDC estimates that ~14% of people in the US have antibodies against Toxocara spp., suggesting that tens of millions of Americans have been exposed to these parasites at one or more points in their lives.

The presenter's data, combined with the CDC's estimates of exposure in the US, suggests that a majority of those exposed to Toxocara are from disadvantaged communities, where public health initiatives fall short. This means that health services are not doing their jobs to protect all people within a community. We can't just protect select groups. All people have a right to be informed of what they may be exposed to in their local environment, and what local organizations (whether nonprofits, government organizations, or research initiatives) are doing to minimize risk!

If you are interested in this specific project, here is an older youtube video of the speaker describing her research:

Its important to remember that the concept of global health affects people around the globe, especially children, no matter where they live or how developed their environment is. Public health interventions have helped reduce the number of diseases that many people in developing countries would be exposed to, but no one lives in a sterile environment!

Monday, June 26, 2017

The Bite of Summer

It’s starting to get really hot as summer sets in for many regions of the world. Even in the last weekend, we had temperatures of 100F throughout the Bay Area (where’s my “June Gloom”?). Over the last decade, we have seen record-breaking temperatures and drastic changes in seasonal climate, in which only some people believe are actually real and worthy of concern. When we think of summer, many people try to make the most of the longer hours of daylight and more palatable temperatures by spending more time outdoors. This simple act of migrating towards wilderness, combined with shorts and tank tops, makes for a memorable “meet-cute” scenario, only instead of casually encountering the love of your life, you’re mingling with vectors that harbor disease.

 My husband often calls me a buzzkill because I can’t help but interject when friends, relatives, or acquaintances tell me that they are planning a summer trip to a location that I know is endemic for one, two, or many vector-borne diseases. “I hope you are bringing some DEET,” I say, explaining that all of the information you need is conveniently located on the and CDC websites. People often get pissed off when I suggest they take precaution instead of flaunting the new swim suit they’ve purchased just for this trip. Whether they take my advice or not is completely their choice, but I can’t help but feel like I’d be partially liable if I didn’t at least warn them.

Many people are still afraid of traveling to tropical islands and throughout South America, as Zika is still in recent memory, and many parts of Europe, for fear of being attacked by a terrorist. Instead, people are opting to explore the natural wonders in their own “back yard”, stating that it’s not only “cheaper, safer, and less of a hassle”, but also that they are afraid He Who Shall Not Be Named might start selling off our National parks for industrial use and that they’ll miss the Instagram photo-op forever if they don’t go now.

Are we really safer in the United States? Sure, there are many reasons to believe that, from an infectious disease standpoint, we are. We haven’t had autochthonous malaria here since the days of our founders, and most people have access to and choose to get vaccinated.

But people die or suffer from chronic conditions as a result of infectious diseases here all the time, many of which can be prevented with basic action.

I write about tick-borne diseases almost every summer, and for good reason. Tick-borne diseases are spread by ticks, and come in the variety of flavors. Many are treatable if caught before chronic illness sets in, as with Lyme disease, but there are still some that cannot be treated. In all cases, the tantamount risk lies with getting bitten by a tick. Without the tick, you can’t get an infection. It’s as simple as that.

Beautiful image of a blacklegged tick from

But we all do things that we shouldn’t. I’m guilty of it too! I run my local trails in a t0shirt or tank top, risking tick bites every time I do it. Why do we refuse to let these vectors take control of our lives? Confidence, maybe? Blissful ignorance associated with a “that won’t happen to me” attitude? I’m not sure.

With that little diatribe, let’s talk about Powassan virus, or “POW” for short. POW is an RNA virus from the genus flaviviridae, meaning it is related to many well-known mosquito-borne viruses like dengue virus, West Nile virus, and yellow fever virus. POW is definitely a lesser-known tick-borne disease, because I think most people only have space for Lyme disease in their cerebral storage. There have only been 75 confirmed cases of POW infection in the US in the last decade, so it’s not as sexy to the news as larger outbreaks. Yet, it’s one to note, because there are no treatments available, aside from symptomatic treatment. According to the CDC, POW neuroinvasive disease cases have been reported in Maine, Massachusettes, Minnesota, New Hampsire, New Jersey, New York, Pennsylvania, Virginia, and Wisconsin between 2006 and 2015.’’

That’s right, it’s a neuroinvansive disease, which means after being bitten by an infected tick, the virus can infect the central nervous system, causing encephalitis and meningitis. Upwards of 10% of cases are fatal, and the CDC reports that approximately half of those infected suffer from permanent neurological symptoms.

Image from
 Not only does the warmer weather drive humans outside, it also expands the territories where many vectors, like mosquitoes and ticks, can survive and thrive. As temperatures increase and stay warmer longer, tick populations have expanded, increasing the likelihood of being bitten. Many predict that there will be a dramatic increase in the number of POW infections this year, as weather continues to warm.

There is no treatment available for POW infection, aside from symptomatic treatment. Since POW is a virus, the antibiotics used for Lyme disease won’t work on a POW infection. Yet, most people who are infected are asymptomatic, and won’t experience any of the symptoms of POW disease. POW isn’t transmitted from person to person, so there’s risk of unknowingly infecting others if you are infected.

If you’re planning a camping or hiking trip, or you’re an avid trail runner like me (and by avid, I mean, I’m amateur at best), I suggest reading over these tips on preventing tick bites, and remember that POW cases have only been detected in the northeastern states, and around the Great Lakes.

 If you do find a tick on you, here’s a video that shows how to remove a blacklegged tick:

Sunday, February 26, 2017

Give us a kiss

I know I'm a little late to the Valentine's-themed blog update game this year (and, like, every year? Let's be honest), but I was busy celebrating a general feeling of love in my life by grading midterm exams all night long. But, in honor of St. Hallmark (har har), I'd love to tell you about an unforgettable kiss.

South America is famous for romance and religion; two concepts that seem to overlap regularly throughout history. Given the tropical climate that engulfs Central America and most of South America, and the common built environments (housing structures, etc.) in rural areas, South and Central America are also endemic for a number of neglected tropical diseases. For example: despite the fact that a yellow fever vaccine exists, there is a huge yellow fever outbreak happening in Brazil right now. This just shows that with the right environment, if preventative measures (like vaccines) aren't required, then the disease will prevail.

Aside from our well-known and beloved mosquito vector, Central and South America are also home to an incalculable abundance of other insects that have the ability to spread many different diseases. One of my favorites (so to speak), is the triatomine bug, AKA the "kissing bug" or the "assassin bug".

Triatomine bug on a knuckle. Image borrowed from The Tico Times
These relatively large insects are bloodsuckers, meaning they take a blood meal from mammals. Due to their need for blood, land clearing, and human encroachment into heavily forested areas, many species of triatomine have adapted to living in and around housing structures. This environmental cross-over helped our friend, the triatomine bug, to start transmitting a number of diseases. The most common disease they spread is the protozoan parasite Trypanosome cruzi, which causes Chagas disease.

Trypanosome cruzi next to a red blood cell. Image (c) to Pearson Education.

Triatomine bugs, known for the unforgettable kiss I mentioned earlier, are nocturnal and attracted to carbon dioxide, which we emit constantly as we exhale. Humans exhale the highest concentration of carbon dioxide in one location while they are sleeping, because most people don't move around as much while they are out cold.

After biting an infected animal or human, the bug now contains the parasite and is able to transmit it to another being. The infected bug bites and draws blood for a blood meal while defecating on the surface of the skin. The bite is usually painless and doesn't wake the latest victim.

By including the act of defecating during feeding, the triatomine bug deposits T. cruzi onto the skin. A combination of the irritation of the bite, and a mild allergic response to the feces, causes the skin to feel itchy. Scratching the itch helps move the feces and parasites into the bite wound, and infection ensues. After scratching, the parasite can also make their way into the body via mucosal tissues in the eyes, nose, and mouth, reaching the bloodstream through penetration of the delicate tissues. The parasite needs the triatomine bug to break the skin, since it is too thick for the parasite to penetrate on its own.

This amazing image is from this publication.

This complete life cycle diagram is courtesy of the CDC.

Fever and swelling of the lymph nodes kick off the presentation of symptoms. A sore may develop at the site of the infection, and if the person was bitten on the face, a presentation called Romaña's sign causes distinct swelling around the eye. Romaña's sign occurs in approximately 50% of infected individuals, and is often considered one of the tell-tale signs of infection.

Romaña's sign in the left eye, image from the WHO and the CDC

If not treated during the acute phase of infection, after initial symptoms subside, the chronic phase of Chagas disease sets in. Chronic Chagas disease can cause major complications to organs and entire organ systems, such as irreversible damage to the heart, intestines, and liver. Its estimated that over 25% of infected individuals develop potentially fatal damage to the heart.

Treatment for Chagas disease is usually a combination of benznidazole and nifurtimox, anti-parasitic medications that attack T. cruzi. This treatment must be given during the acute phase, when the parasite can be found in the circulatory system. In endemic regions, treatment is typically available. Yet, in the US, you must have a confirmed diagnosis of Chagas disease in order to obtain the treatment from the CDC, because it is otherwise not available. Diagnosis is performed by a blood smear viewed with a microscope to identify the parasite in the blood. Other tests, such as PCR, can be performed, but the blood smear is the gold standard in identification and diagnosis.

Triatomine bug populations reported in the US, via the CDC

The vector, triatomine bugs, are found throughout a large part of the southern US. A small number of locally-acquired cases have been reported, but not enough to cause huge alarm. Also, there are a number of ways this parasite can fail to infect you.Without the presence of the vector, the parasite cannot infect you. The parasite cannot penetrate the skin on its own, so unless a triatomine bug successfully bites you, or you have an open wound that is exposed to the feces of triatomine bugs, you are not at risk. Additionally, triatomine bugs don't always defecate when they feed.

The best way to limit exposure to Chagas disease is by reducing your exposure to the triatomine bugs, since there is no available vaccine, and treatment can be difficult to obtain in the US. Monitoring your house for triatomine bugs, cleaning away debris to reduce environments for their ideal hiding places, and if you are truly worried, regular insecticide spraying can all reduce your risk of exposure. While most insecticides have not been approved for use in the US against triatomine bugs, long lasting insecticides have been shown to kill them.

Image from Chagas Initiative Argentina

Friday, January 20, 2017

A Sense of Urgency

I haven't posted anything in a while, simply because the last few months have been occupied with self-reflection and constructing a plan of action for 2017. After the US Presidential election results were released, it seemed like a waste of time and energy to write about some disease that most people in the US will never even learn about, let alone be exposed to.

I was caught in an ambiguous fog of wondering whether the work that I do (my research, not necessarily this blog) is truly worth it, or if I'm just contributing to the unsustainable aspects of "global health". It can be frustrating when your subjects are on another continent, in another time zone, and will never interact with you face-to-face. Its also frustrating when you realize that you are just another white lady that claims a passion for global health/"wanting to make a difference". What does that mean, really? And frankly, what does that mean now that our government is lead by someone who believes in business over, well, everything else?

Community health workers in Madagascar (photo from K4Health)
How do you cope with being a person of the scientific community who wants to help initiate positive change, such as expanding the development and access to treatment and vaccinations for neglected diseases, improving access to clean water and sanitation technologies, or expanding educational and economic opportunities for young women in developing countries (just to name a few popular and reoccurring themes in global health), but also realizing that you may be forcing a very biased view on communities that are rarely empowered, but instead labeled has victims? (example: Many journalists claimed the cause for the last, explosive ebola outbreak was initially due to "ignorance" of the affected communities). Similarly, how do you prioritize issues abroad when there is so much happening in your local communities?

I recently finished reading Sometimes Brilliant, by Dr. Larry Brilliant, which details his journey through being a hippy MD with a passion for social justice and civil rights, and how he managed to find a spiritual connection to India while working to eradicate smallpox. On a number of occasions in this story, Dr. Brilliant (lovingly nicknamed "Dr. America" by his guru) questions his actions and whether his efforts are actually helping people in the long term, or if he's contributing to immediate yet unsustainable aid. This obviously spoke to me on a number of levels, but didn't help guide me to a solution (the answer isn't always broad and right in front of you, I guess).

Here's a great interview with Dr. Brilliant on Marketplace.

Dr. Larry Brilliant (center) in India in the 1970s, working to educate communities and eradicate smallpox.
The beginning of the year coincides with my birthday, and instead of setting resolutions, I try to revisit the actions I've taken in the last year, and reflect on whether I'm having enough of an impact, giving enough of myself (energy, time, money, values, etc.) to others. This year, I wasn't feeling great about it, because I feel like there isn't enough time in one day, or even one year, to give enough of oneself to a cause (or causes) that will result in a true impact, a change, an improvement.

This dilemma is amplified by the fact that I spend a majority of my time and effort working in a lab at one of the most well known, private universities in the world, wherein I primarily interact with other white people, and everything sparkles with privilege and ongoing gifts from wealthy donors. Despite being in such an environment where low-income students get to attend for free, or where new and extensively valuable discoveries are made regularly, I'm not working in the hospital directly, where I could leave my workday feeling like I had a direct impact on someone's quality of life, or interacting with the students, who will go on to spread their expert educational experiences to many parts of the world with their future careers. When you work in such an environment, it is not clear who is "on your side" politically, or who is there to make a difference versus for the prestige of working with such a well known university. Its easy to feel isolated in a well-off environment when you are aware of inequalities.

Earlier this week, I attended a Global Health Symposium. It was a great event last year, but I wasn't expecting anyone to speak about the real issue at hand: How can we navigate global health issues with the new switch in government? It is typically not talked about, because you never know who voted for which party, or who actually believes the wall should be built. But without discussing such issues, it can make you feel like you are a part of the problem just by going to work.

The opening keynote address was given by Diana Chapman Walsh. Dr. Walsh was president of Wellesley College until 2007, and currently serves on the board of the Broad Institute of MIT and Harvard. She is also on the board of directors for the Mind and Life Institute, where she gets to work with the Dalai Lama. At first look, admittedly, I stereotyped and judged her. I thought, "she appears to be another 'rich white lady' who will talk about working together and doing good things for people of the world, but her talk will be empty and uninspired", because that's how jaded I've been feeling about everything lately. I was clearly desperate for inspiration and guidance.

Diana Chapman Walsh. Image borrowed from GoldLab
She proceeded to talk about the urgency of collaboration and navigating our resources while we still have access to them. Stating "they told me I could be political", she spoke outwardly about how white supremacy has put us in our current position, and how it is a danger for the future of global health. Frankly, white supremacists do not value the health and wellness of other, non-white/non-(North) Americans. How does that view impact the health of our nation, and the health of people around the world? Negatively. This new administration is not going to value the federal organizations that perform research and provide aid that benefits people worldwide, as 'they should be able to take care of themselves'. Statements like these do not acknowledge that there is a monopoly on resources that are a fundamental human right. Instead, these resources are traded strategically, doled out as bribes for economic advantage (example: mining natural resources in Africa, trading access to such resources strategically for money and power). Don't even get me started on the white supremacist view of developing countries through the narrow lens of tourism and hospitality industries (Dr. Walsh didn't touch on this, but I bet she has thoughts about it).

Dr. Walsh spoke of climate change as a vital component of global health, which is not a view you hear regularly. You hear of polar bears losing their habitat, and small island villages being swallowed by rising sea levels, but with the polarized nature of climate change, no one likes to talk about the increased spread of disease, how it is affecting animal populations, or how it is going to get extremely difficult for some regions to access basic resources, like clean water and food. Why would you allocate funds for research and innovation to combat these problems if you don't believe in climate change? Also, why would you believe in climate change when you cant see past your own bubble?

A bad photo of an inspiring talk.
What especially surprised me was how Dr. Walsh openly expressed her support for Black Lives Matter. I have never heard anyone at our university (outside of my immediate lab group) express such views openly. It hit me like a punch in the face, because I thought she was going to be someone who wouldn't take a stand, and who would most likely be an expert at straddling the fence. But, no, I was wrong! What a refreshing surprise! She used her position of power to say that we need to consider our local communities as a part of our global health initiatives. What that showed me is that we can be an example, and we shouldn't keep quiet. Also, maybe if we start listening more, we can learn how to get things done? Here's an article that details "8 Black Panther Party programs that were more empowering than federal government programs", just as one example.

Amazing photo from the Atlanta Black Star
A few people referenced the latest Oxfam report on inequality that states "62 people own the same as half of the world", and 53 of them are men (surprised?). Only until the end of the day was the concept of engaging these powerful few for philanthropic endeavors. I mean, look at what a tremendous impact Bill and Melinda Gates have had on research, innovation, and impacting global health. It just has to be seen as a priority.

So where do we go from here? Which causes are you passionate about? How do we harness these ideas for fuel for our activist fire? I hesitated to use the word "activist", but then realized that standing up for global health means being an activist for social justice, no matter where your efforts are targeted.

In a specifically memorable moment of Dr. Brilliant's book, he tells a story about being caught in the middle of a dilemma: to play the game of corruption that may lead to long-term support for their smallpox eradication mission, or to stand up for noble action and do what is immediately right for the cause. He sought guidance from another spiritual leader and was told to consider the question "how are my actions affecting the children who are sick and dying from smallpox?" with every move. Truly how do you navigate these situations when there is a business side to global health? We cannot always only lead with our hearts, because funding will run out in a flash.

Global Goals taken from

I'll still cover infectious diseases, but the tone of my blog may change. There will be more calls to action, for sure. Global health is not only up to the righteously motivated or the extensively educated, especially when we consider global health as all encompassing.

Thanks for the much needed inspiration, Diana Chapman Walsh and Larry Brilliant. I'll see you on the front lines.

This one's for you, Trump:

Note: I've received a number of requests to do a series of posts about vaccinations: how they are developed and manufactured, how they work, etc., so I will be dedicating my next few updates to that subject.

Friday, September 16, 2016

CCHF: The Western European Tour

In 1944, a tick-borne virus characterized in Crimea was name "Crimean hemorrhagic fever virus", yet 25 years later, the vector was identified in the Congo. Hence, Crimean Congo Hemorrhagic Fever, or CCHF for short, was born (in the "I've given this naturally existing thing a name so it shall be seen as new" sense). As all vector-borne diseases are limited by the regional distribution of their vectors, it is no surprise that news outlets are currently describing CCHF as a "new" viral disease. Spread primarily by the Hyalomma species of tick, CCHF has been historically limited in spread, with cases primarily showing up in certain regions of Africa, the Middle East, Eastern Europe, and some parts of China.

Map borrowed from the CDC (2014 version).
Let's look at some older maps that contrasts the distribution of the Hyalomma species and historical cases of CCHF:

Map from the WHO in 2008

Image from

There are a number of factors that have contributed to the spread of CCHF virus. CCHF virus is a zoonotic virus, meaning animals, such as livestock and domesticated animals, may also be infected. Many species of birds appear to be resistant to CCHF virus, with the exception of ostriches. Outbreaks have been linked to ostrich abattoirs (or slaughterhouses) in South Africa, but the animals do not present with disease symptoms or consequences. Primarily cattle, goats, sheep, camels, and hares or rabbits are susceptible, and act as the amplifying host. Humans can become infected as a result of contact with an infected animal tissue or blood, so it is easy to see why herders and abattoir workers are at high risk for exposure. Human-to-human transmission is possible through contact with infected bodily fluids, which puts health workers at risk as well. Cases have been traced back to exposure through contaminated medical equipment, although that is fairly rare.
Viral life cycle image via the CDC
So why are we seeing CCHF virus labeled as "new"? "New" is the media's historically ignorant term for "emergent", meaning these infectious diseases have been around for a while (some for centuries, even), but environmental and civil factors are influencing spread to new regions. Even the slightest change in seasonal climate or average annual temperature can create a hospitable environment in places that were inhospitable to these disease vectors. We also have a very developed view of the world, where it is hard to see that human actions, such as spillover into forests regions for industrial purposes (extracting natural resources or large-scale plantations for the production of resources), and development purposes (houses, houses, everywhere), can influence the introduction of these diseases to new populations. Not only are the vectors moving into our developed areas, but we are constantly invading and inhabiting natural habitats and contributing to the zoonotic nature of these viruses (and other infectious diseases). After all, we are animals, too.

Forbes, with their obnoxious refusal to let you view articles on their website while using an adblocker plugin, says that you should be worried about CCHF. The first local transmission of CCHF virus was reported in Spain this year, and the patient died. A nurse was also exposed as a result of this case, which lead to close monitoring of many people from the medical team and local community. The presence of CCHF virus in Spain has been known since 2011, when the West African strain of CCHF virus was isolated from ticks in Caceres province. Up until that point, the Balkans were the western-most region known with reported cases of CCHF.

Onset of CCHF is quick, with sudden onset of high fever, severe headache, back and joint pain, stomach pain and vomiting. Patients may appear flushed with red eyes, face and throat, with a patchy red palate. Jaundice and the onset of neurological complications can arise.The hemorrhagic nature of the disease begins with severe bruising and frequent, severe nose bleeds, or uncontrollable bleeding at the site of injection. Outbreaks generally have a case fatality rate of 40 - 50%. Treatment is limited to supportive care, and there are currently no vaccines available to humans or for use in livestock populations.

Image from

Image from Wikipedia
There are many other hemorrhagic fevers, including Ebola virus (EBOV), Marburg virus (MBGV), Lassa virus (LASV), Rift Valley fever virus (RVFV), dengue virus (DENV), and yellow fever virus (YFV). Differential diagnosis, how we determine which virus is causing the hemorrhagic disease, is very difficult, as many of the symptoms overlap and rapid testing is not always available. In all of these viral hemorrhagic diseases, infection can impact liver cells and liver function. Impairment of liver function can decrease synthesis of protein that initiate clotting. This most likely occurs due to the body's response to severe disease and shock, as more liquid/unclotted blood can disseminate faster to all organs. Infection of liver cells can also cause an increase in clotting proteins, causing small clots to form, blocking blood flow. Hemorrhagic fevers also effect the permeability of blood vessels, causing the severe bruising and bleeding in tissues and orifices, like the nose, gums, or vomiting blood as a result of severe internal bleeding.

If you are following the advice from Forbes, and deciding to worry about CCHF, take action. Check yourself for ticks after spending time outdoors in wooded areas, places with tall grass, or wild animal exposure. Wear long sleeves and pants while spending time outdoors to limit your skin exposure to ticks (you can even treat your clothing with repellent; learn how here). Lastly, if you find it a tick on yourself, be sure to remove it carefully without pulling the head off or smashing the blood-filled body. If you are worried about disease exposure from said tick, do your doctor a favor and save the tick! It can be sent to a lab and tested, but act quickly as these viruses can be difficult to isolate from old material.

Wednesday, August 10, 2016

Beasts Aplenty

The world is on fire about arthropod-borne viruses, or "arboviruses". The simple mosquito bite can transmit a battery of diseases, including the currently popular West Nile virus, dengue virus, and zika virus. While these viruses are not new, the emergent nature has taken our media by storm, and is illuminating the universe of zoonotic diseases.

There's one virus, though, that for me, was the original. This virus has infected history and popular culture alike, but still hasn't achieved the level of fear that we see with some of these other, more emergent viruses. The fact that more people aren't absolutely terrified of this virus is beyond me, considering that it is the most deadly virus in the world, whereas dengue and zika have relatively low mortality rates.

Image from 7 Bloodcurdling Werewolf Tales That Will Keep You Up at Night
The rabies virus is a unique, non-segmented, negative stranded RNA virus of the Rhabdoviridae family. Unlike most diseases that hijack the circulatory system for dispersal through the body, rabies attacks the nearest nerve. The virus actually replicates in the nerve cell, slowly moving up to the brain.

The rabies virus is quite literally shaped like a bullet. The lipid envelope is lined with glycoproteins that help with viral attachment.
The slow progression is part of the issue, because most people don't know they've been exposed to the virus until much later, when the symptoms start to set in. By the time symptoms occur, the virus has replicated and multiplied significantly, so a large amount of virus hits the brain.

The first symptoms are nonspecific and mild, with fever, weakness, headaches, and malaise. Some patients report a tingling and itching sensation at the site of the bite. After the nonspecific symptoms, confusion, anxiety, and agitation set in. Cerebral dysfunction leads to fits, and the body starts to lose the ability to sense temperature, pain, and pressure. These fits lead to erratic behavior.

It is common for patients to experience a phobia of water, too. As the virus is most commonly transmitted by bite, the fear of water is an evolutionary advantage for the virus. Without water, the virus is concentrated in saliva, without being diluted by water, making it more likely to be transmitted.

It is also possible for patients to experience "dumb rabies", with lethargic and comatose-like symptoms prior to death.

Once these symptoms start, recovery and survival is extremely rare. Disease progression usually lasts between 1 and 3 weeks, from start to finish. There have been only a small number of people who have survived a rabies infection, some from experimental treatments, and others for unknown reasons. Post-exposure prophylaxis of human anti-rabies antibodies needs to be administered before the onset of these symptoms, otherwise death is guaranteed.

Given its intense lethality, rabies has inspired a significant amount of medical development. Louis Pasteur developed the first rabies vaccine in 1885. Pasteur achieved successful development of the vaccine by serial attenuating, or weakening the virus in rabbits.

Rabies kills approximately 60,000 people a year, worldwide. We don't typically worry about it here in North America, due to pet vaccination and local animal control, so most of the deaths occur in poor, rural, and developing regions of the world. In the last two weeks, though, Sheffield, MA has been experiencing the worst rabies outbreak in decades. Residents of Sheffield have reported rabid foxes, skunks, and even a RABID WOODCHUCK.

Rabies has played an integral part in the development of some of the most horrific monsters. The concept of man morphing into a wild beast evolved from human exposures to animal diseases. The best examples of this are the werewolf and Dracula (or, vampires in general).

It all starts with a bite.

Tuesday, May 17, 2016

Brought to you by the letters HBV

May is Hepatitis Awareness Month (according to the CDC), so I'm going to focus on something I get inquiries about all the time.

Hepatitis is a viral disease that can cause liver damage that can progress to liver inflammation, scarring (fibrosis), cirrhosis, or liver cancer. Disease progression depends on the virus, and other existing health issues (excessive use of alcohol and other substance abuse, autoimmune disease, etc.).

There are 5 viral types of hepatitis, aptly named A, B, C, D, and E (or HAV for Hepatitis A Virus, HBV for Hepatitis B Virus, and so on). We don't usually hear about hepatitis A and/or E here in the US, because they are transmitted by ingesting contaminated food or water (you're more likely to get listeriosis here!), which is mostly associated with developing countries and poor sanitation. If your an avid traveler, you've probably already received a HAV vaccine.

Hep B and C, though, are common in the US, and worldwide, and this is where the the inquiries come in. Hep B, C, and D are spread by contact with contaminated bodily fluids, such as blood and semen. The most common methods of transmission are through unprotected sex, and through sharing or using contaminated needles (drug use, tattoos, piercings, birth, and medical procedures). There are vaccines available for Hep B and D, but not C. Actually, the HBV vaccines also protect against HDV! Since most people do not know they are infected with a hepatitis virus, and HBV, HCV, and HDV are prevalent worldwide, the HBV vaccine is recommended for all newborns in the US.

Hep B and C kill more than 1 million people every year, and its not an easy death. Liver disease is painful, and the treatments few treatments for hepatitis can be incredibly expensive. So, to answer everyone's question all at once: Yes, I do believe the recommended vaccine schedule is necessary and important for your child, and all children for that matter. 

Before I go on, let me just say that, as someone doesn't have kids of my own, I can't imagine how scary it must be at the beginning. The dichotomy of wanting to protect your kids from everything while not having them undergo a ton of procedures and get a bunch of shots because they are fragile little beings must be scary. It's ok to try to figure out what is right for you and your child, because some things are unnecessary (baby yoga? I don't know)! But, I believe vaccines are not one of those unnecessary things.
The following are most common things I hear about the HBV vaccines from concerned parents. Just a note: my language in this section is referencing people who do have access to regular medical care, and may or may not be taking advantage of it. This is something that all parents should have access to for their children, but sometimes it just isn't possible (for a number of reasons). Most often, people who are questioning the use of the HBV vaccine (and others) do have access to quality medical care, yet choose not to follow the guidelines. Descriptive demographics of the people who are chosing not to vaccinate their children include white, upper middle class or upper class, and college graduates.

So, with that being said, here are the most common things I hear about the HBV vaccine:

1. "Why would I give my baby a shot (3 to 4, actually!) for something you can only get from having sex?"
There are so many assumptions being made here. First of all, you should be glad that you have access to, and are benefiting from the privilege of having access to vaccines for your child and yourself. Most kids don't get vaccines, because they aren't mandated or they are too expensive or not available to them based on where they live. The fact that you and your child get to benefit from that is not something at which to scoff! Many children don't even live past the first few years of life because they don't have access to quality medical care and treatments.

Secondly, over 2 billion people have been exposed to hep B, and as I stated above, most people don't know that they are infected. That means there are many opportunities for your child to unknowingly be exposed. There are even opportunities for family members who don't know that they are infected to expose your kid during infancy. This vaccine will protect your child through their exploratory stages, when you might not always be around. I can't even tell you how many kids at my middle school thought blood pacts weren't serious (I think we can mostly blame that on 90s movies, right?), or in high school when everyone experimented with making their own tattoo guns. Or even had unprotected sex because they were too embarrassed to buy condoms or felt too invincible because "well, I'm not going to get AIDS from you, right?" Let's face it, pretty much every kid, teenager and young adult makes odd choices when they are figuring everything out, and that exploration really shapes who they become as adults. So, if there is a vaccine available to them that may offer some protection throughout their lives, why would you deny that?

2. "It just seems like a lot for a newborn to handle." or, alternatively,  "That's a lot of chemicals to put into a newborn."
The hep B vaccine has actually gone through a few iterations before arriving at it's currently available form. In 1986, manufacturing switched to using recombinant DNA, which is significantly more safe (see: 100% safer, because it is physically impossible to get hepatitis from the vaccine) than the original product. The vaccine has been clinically tested (on many animals and humans) and approved for use in children. The recommendations set for these vaccines are based on a) the earliest safe and effective usage of the vaccine by the immune system (i.e. - will my immune system even respond to it?), how long the immune system response will last (will I need a booster shot in the future, or will this one time vaccine protect me for life?), and the need (will I potentially be exposed to the pathogen at this stage in my life?). There are many vaccines that kids in the US don't get, because they won't need them (see above where I explain that the hep A vaccine is mostly given to travelers headed to regions with poor sanitation). But, as stated above in #1, there are a lot of opportunities for people to be exposed to HBV and HDV.

3. "I'll just give it to them later in life."
Sure, do that, but they will hate you for it. I remember having to get my hep B vaccines. It hurt really badly! And I remember it hurting because I wasn't a newborn. Also, I don't say this as a scare tactic, but every day without the vaccine (or other ones, for that matter), are days that your child's immune system isn't primed and ready to go. So, for that reason, its really silly to wait, especially since most people don't need boosters.

4. "Why does anyone care what I do to my child?"
Every child without the vaccine is at risk of being exposed to the virus. If your child is infected at any point in their life, they have the ability to transmit (or spread) the virus to others, especially if they do not know that they are infected and do not take precautionary measures (using condoms, not sharing needles, etc.). Some people with compromised immune systems cannot get certain vaccines, and are therefore at a higher risk of getting infected, and developing chronic or severe disease. If you do not vaccinate your child, your child may be responsible for unknowingly spread the HBV or HDV to someone with a compromised immune system.

5. "Most people only have an acute infection that goes away on its own."
No, most ADULTS experience acute disease. Only 2-6% of adults develop severe or chronic hepatitis, whereas 90% of infected infants become chronically infected. The risk of pre-mature death due to liver disease and chronic complications from hepatitis (mostly liver failure and liver cancer) is increased by up to 25% if a child is infected in their first 5 years of life. Three shots can completely eliminate this risk for your child. The hep B vaccine can also eliminate the risk of hepatitis-linked treatments, like invasive surgeries, transplants, or cancer treatments, which increase the risk of premature death even more, and are just not easy for a child to endure.

If you are still questioning whether to vaccinate your child for hepatitis B, I recommend you talk to your pediatrician about the statewide mandated guidelines and federal recommendations. As I stated earlier, I'm sure having a child is scary. There is a lot of information out there, and it is hard to know what to believe. But, vaccinations are not something that should be questioned. It has been proven time and time again that they are safe to your child, and safe for the community, and have effectively eradicated some diseases. It is okay to be cautious, but it is also okay to trust science.

Happy Hepatitis Awareness Month!