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 travel.state.gov 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 coppelabs.com


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 webmd.com
 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 One.org

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.