Student guest post: Mission Impossible: Fighting Zoonotic Infections in Nicaragua

Student guest post by Brandon Woods

A Dangerous Paradise

From jungles with jaguars to crystal blue lakes with freshwater sharks, Nicaragua is one of the most beautiful and dangerous countries in Central America. The brilliant biodiversity attracts millions of tourists each year and the looming volcanoes that pepper the landscape can be an exciting yet unsettling sight. However, in reality much of the danger in Nicaragua comes from the risk of infectious diseases. For example, if you’re planning to travel to this tropical paradise anytime soon, the Center for Disease Control (CDC) states that international travelers are at risk of contracting Typhoid fever, hepatitis A, hepatitis B, Leishmaniasis, malaria, dengue, rabies, and more! As a dual degree veterinary medical and public health student, I am fascinated by these infectious diseases and want to learn how they interact with the environment, people and animals. Many of the diseases that the CDC listed are called zoonotic diseases, or diseases that are transmissible between animals and humans. Other zoonotic diseases you may know include ringworm, Lyme disease, and Cat scratch disease. Whether you own a pet, like to travel, or simply enjoy spending time outdoors, you are at risk of infection because these zoonotic diseases are increasingly emerging worldwide and are becoming a serious public health threat. During the spring break of my first year of veterinary school, I traveled to Nicaragua on a mission trip and got first-hand experiences of these frightening infectious diseases.

 Brandon picture 1

Bed Nets and Bug Spray

Planning for this trip was time-intensive and reminded me of planning for my semester study abroad adventure to Tasmania, Australia. However, unlike my semester Down Under, this trip was coordinated through the national non-profit Christian Veterinary Mission (CVM) whose goal has been to help veterinarians serve others and live out their Christian faith for more than 30 years. Out of all the fundraising and logistics meetings we had, the meeting that stands out the most was when the Iowa State University travel nurse described the laundry list of potential pathogens we could encounter. Our team of 8 veterinary students, 3 veterinarians, and 1 pharmacist would be treating animals in a remote village called Espavel in the jungles of eastern Nicaragua. When I saw that my destination was in the middle of the red zone for malaria on the CDC map, my eyebrows escalated and my stomach dropped.

I was going to fly to an unstable, earthquake-prone country of approximately 5.7 million Spanish-speaking people where malaria was endemic. My Spanish was scarce, but my drive to serve was strong. After I heard that malaria was essentially eliminated from Nicaragua, my blood pressure dropped a few millimeters of mercury. Approximately 84% of the Nicaraguan population is at risk of contracting malaria, according to a UCLA study. However, Nicaragua has experienced a 97% decrease in reported malaria cases between 2000 and 2010. This significant decrease in prevalence was a result of Nicaragua partnering with the Pan American Health Organization (PAHO) in 2006 which heavily implemented stronger surveillance, prevention, vector control, and treatment. Despite this progress, I learned from my undergraduate Lyme disease Honors project that there are always numerous challenges to completely eliminate vector-borne diseases like malaria. For instance, controlling mosquito breeding populations is particularly vexing due to the complex ecology of the parasite life-cycle. In addition, you may have heard about the controversy surrounding toxic pesticides like DDT. My colleagues and I were fortunate for our DEET bug spray and Permethrin treated clothes and bed nets that we brought after skyping our host-country missionaries. I was also relieved that our trip in March 2013 was during the dry season and not during the September-to-January rainy season, when disease transmission is highest.

Rambunctious Rabies

Escaping the endless hours in the frigid, formaldehyde laden anatomy lab and flying to a third-world tropical country to practice preventative medicine was slightly shocking, but totally worth it. On our first day, we drove through the littered streets of Catarina to an outdoor shelter where we set up a temporary clinic. The local children brought their pet dogs and we treated them with Ivermectin and other anti-parasitic medication. Many animals were very thin and infested with fleas and ticks. However, it was rewarding to interact with the children and walk them through a brochure that described both healthy animal care and the Gospel of Jesus Christ. Then suddenly one of my colleagues was bitten by a dog! He was trying to give a rambunctious mixed-breed a pill to protect against heartworm disease and the next thing he knew, the dog bit him in the hand. He quickly washed the wound with soap and water and bandaged it. Fortunately, everyone on our veterinary team was already vaccinated for rabies prior to the trip because it’s a requirement to enter veterinary school. He also followed up with post-exposure rabies prophylaxis when he returned home.Brandon picture 2

Rabies is one of the deadliest and most notorious zoonotic diseases in the world. Rabies is endemic to Nicaragua, often occurs in poor rural communities, and the most common source of transmission is when a dog bites a human and delivers the fatal RNA virus. According to the World Health Organization, potentially any mammal can contract rabies, and common reservoirs in the USA include skunks, foxes, raccoons, and bats. Although rabies cases can be successfully treated, it still persists worldwide killing more than 55, 000 people each year. The Center for Food Security and Public Health (CFSPH) at Iowa State University is an excellent resource that provides more information on rabies and preventing zoonotic diseases. Reducing the prevalence of rabies globally requires a multinational effort and the World Rabies Day Initiative was founded solely for this mission and has already collaborated with 150 countries and vaccinated over 7.7 million dogs.

Tasting Iguana and Tackling Typhoid

It’s a good thing I like rice and beans, because that was the bread and butter of most of my meals every day. Hiking to farms builds an appetite and one day we had to traverse across a narrow blank that stretched precariously over a ravine. After we arrived, we vaccinated over 100 head of cattle for clostridium, anthrax, and Dectomax. Dectomax is an injectable drug used to control parasites like hookworms, round worms, grubs and mites. When we returned to the main village and got out of the blazing 90+ degree sun, the crispy, plantain chips with a glass of freshly squeezed tamarind juice was an irresistible snack. However, the most memorable meal of all was the morning the villagers surprised us with two 5 foot long iguanas! A few hours later, I was savoring some delicious iguana meat seasoned with local spices and vegetables. Cooking wild reptiles is foreign to us in the developed world; likewise, the way many Nicaraguans prepare their food is also different.

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Sayings like, “Don’t drink the water,” or ‘Boil it, cook it, peel it or forget it,” come to mind when traveling abroad, and they couldn’t ring more true for my experience. Food-borne illnesses are another great example of how veterinary medicine and public health overlap. I’m enrolled in the dual DVM-MPH degree program at the University of Iowa’s College of Public Health and learned that food-borne epidemics are a major focus of research in epidemiology. From mild cases of spoiled potato salad on romantic picnics to church dinner outbreaks from contaminated home-made ice cream, food-borne illnesses can range in their severity depending on your pre-existing health and the dose and type of microorganism ingested. One of the Nicaraguan diseases that I was vaccinated for before my trip was a food-borne illness known as Typhoid fever. Thankfully I avoided this illness; however, I couldn’t escape the wrath of Montezuma’s revenge, or traveler’s diarrhea, most commonly caused by enterotoxigenic Escherichia coli.

Typhoid fever is transmitted through contaminated food or water and is unique among food-borne pathogens because it only affects humans. In fact, some individuals can unwittingly become carriers of the bacterium and transmit the disease to others through improperly prepared food, like the infamous Typhoid Mary. This disease is caused by the bacterium Salmonella typhi, which is one of over 2,300 species of Salmonella and can be treated with antibiotics, according to the USDA. Other Salmonella species are also common among household, cold-blooded critters like turtles, frogs, iguanas, and snakes, so it’s important to always wash your hands after handling these pets.  Like malaria and rabies, Typhoid fever presents challenges for eradication in developing countries where poverty limits accessibility to clean water, pasteurization, and proper sanitation and hygiene. For example, I had never taken a well-water bucket shower before, and although the murky water felt refreshing after a long days’ work, I came to more deeply appreciate the luxuries of everyday plumbing and electricity.

Collaboration is Key

An empowering lesson that continues to inspire me was when I participated in a humanitarian collaboration. Before our departure, we communicated with another mission team from an Arkansas Baptist church that would work at the same time as our Iowa State Christian veterinary mission team would work over spring break. The goal of the Arkansas team was to provide humanitarian care while the goal of the Iowa State team was to provide veterinary care. For instance, the Arkansas team brought donated shoes and eyeglasses, provided nutrition education and had a dentist and nurse that pulled teeth. On the other hand, the Iowa State team vaccinated dogs, cats, horses, cattle, and pigs, performed surgeries and provided agricultural advice to farmers. Even though the two teams set up separate clinics to work on different species, we still felt united as one team because we traveled together, ate meals together, and worshiped together.

Brandon picture 4

One sunny afternoon, we asked the human dentist to come over to our animal clinic to pull a rotten tooth out of a horses’ mouth. The dentist had hardly been around horses in his life, let alone stuck his hand in one’s mouth before, but after the novelty wore off, he quickly agreed to help our team. The sedated horse was lying on its side surrounded by curious villagers and veterinary students. The dentist was nervous and the 3 inch long decayed molar kept wiggling out of his grip. Finally, he extracted the tooth and everyone was amazed and overjoyed. It’s a simple story like this that showcases the successful collaboration between veterinarians and other medical professionals that is the goal of the One Health Initiative or the new concept of interdisciplinary healthcare collaboration. In order for us to eradicate these infectious diseases and save lives, it is vital that veterinarians, physicians, dentists, and epidemiologists collaborate and communicate to find solutions.

A Future Fighting Infections

Going on this short-term veterinary mission trip put me in harm’s way, but it gave me real-life experience with infectious diseases, deepened my faith, and strengthened my clinical skills. It was bittersweet to say adios to my amigos, but I know I’ll return to that perilous paradise.  I enjoyed the international fieldwork and cross-cultural partnership because it embodies the One Health Initiative that I highly esteem. From hiking in the jungle on my 23rd birthday to taste-testing iguana to teaching children about pet care and the Word of God, this trip was a remarkable adventure that has forged a new trail for me. I don’t believe it’s an impossible mission, and I am committed to pursue veterinary public health as a career and control zoonotic diseases in developing countries.

All photos courtesy and copyright Brandon Woods. 

Resources:

http://www.who.int/en/

http://new.paho.org/hq/

http://www.merckmanuals.com/vet/index.html

http://www.cfsph.iastate.edu/Zoonoses/

https://www.cia.gov/library/publications/the-world-factbook/geos/nu.html

http://www.fsis.usda.gov/factsheets/foodborne_illness_&_disease_fact_sheets/index.asp

http://amestrib.com/sections/news/ames-and-story-county/student-traces-lyme-disease-ames.html

http://wwwnc.cdc.gov/travel/destinations/traveler/none/nicaragua

http://www.fda.gov/forconsumers/consumerupdates/ucm048151.htm

http://www.cvmusa.org/Page.aspx?&pid=183

http://en.wikipedia.org/wiki/Zoonosis

http://www.worldrabiesday.org/

http://www.onehealthinitiative.com/

http://www.public-health.uiowa.edu/epi/

Student guest post: Tuberculosis: A Real Problem With No Real Solution

Student guest post by Jack Hamersky

After successfully completing a job interview I had the opportunity to take the next step in my employment process: taking a Tuberculosis or TB test.  I have received the test before but never really understood the point of testing for a disease no one ever sees in my community. I always thought, “Why not focus all this effort and money on more prevalent infectious agents such as Ebola or HIV?” You know, focus on something important.  So, as the nurse called me in from the waiting room I began to curse that hard little bubble that would soon be forming under my skin, and the inconvenience it would be to have to come back to this same clinic to have it read.

This same type of experience is known throughout the United States and other developed countries.  However, many people like myself, do not know the importance of this test.  They might not know that this test is a crucial part of the much larger goal of eradicating a deadly and common worldwide disease.

What is tuberculosis and why is it even important?

Tuberculosis is a contagious disease that is found in both animals and humans. The human form of the disease is caused by a group of three bacteria: Mycobacterium bovis, Mycobacterium avium, and Mycobacterium tuberculosis.  This disease can come in two forms: latent and active.  The active form of tuberculosis causes pockets of pus called granulomatous lesions in lungs and has a death rate around 50%. It is estimated that TB infects around one third of the human population on earth and is the second leading cause of death by infectious disease, behind HIV, killing around million people annually, according to the Center for Disease Control and Prevention; CDC (4).  The greatest prevalence of TB occurs in developing countries and their low socioeconomic populations.  This is likely due to the limited availability of health care, poor nutrition, and overcrowding conditions these people face on a daily basis.  Immunosuppressed individuals, such as people infected with HIV, are also more likely to contract tuberculosis.  TB is also very hard to treat and many forms of the disease are resistant to antibiotics.

Another reason TB is so dangerous is the threat of Mycobacterium bovis. M. bovis is another strain of tuberculosis that mainly infects cattle, cervids (deer like animals), elephants, bison, etc (7,10). What makes this bacterium interesting is its been known to infect people through the consumption of raw (unpasteurized) milk or products that were made from that raw milk (1,5,7,10). This zoonotic microorganism is responsible for two percent of all new cases of TB in the US (7) with an even a greater percentage worldwide (6).  The zoonotic nature of M. Bovis allows for it to hide in wildlife populations which act as a reservoir for the disease (6,9). The good news is a campaign to eradicate M. Bovis from the US food supply began in 1993(5). The bad news is that TB remains endemic in wildlife and agricultural animal populations worldwide. The program in the United States has been a success and most of the United States is considered Bovine Tuberculosis free.  However some states, such as Michigan, still find M. bovis in their wild deer herds making the continual threat of reemergence a reality.

So what have we done about this problem?

The United States government has taken a leading role in the fight against TB. It formed the Advisory Council for the Elimination of Tuberculosis to address the growing resurgence of TB in the 1980’s (5). It also passed legislation like the Comprehensive Tuberculosis Elimination Act which called for the increase of federal funding, education, and international collaboration in the fight against TB.  Other non-governmental advancements have taken place over the years too.  A vaccine was created and is now available throughout the world.  Known as BCG, this vaccine is good at protecting children against the disease, however, it loses its effectiveness as children grow older and has not shown promising results in adults (8).  This, coupled with the increasing amount of antibiotic resistant cases (known as Multi Drug Resistant Tuberculosis or MDR TB) once again proves the fight to eradication or even control might be more of an uphill battle then we once thought.

So how is the fight to end TB going?

Over the past few decades we have made progress and in 2011, the World Health Organization reported “The absolute number to TB cases has been falling since 2006”. However, in that same report, the WHO also stated, even though TB cases had dropped, “In 2009 there were almost 10 million children who were orphans as a result of parental deaths caused by TB” (12,13).  As long as there TB is left to reside in our low income populations and in animal reservoirs it will continue to plague millions worldwide.

So where do we go from here?

The continuation and strengthening of surveillance and research projects worldwide is the key to combat tuberculosis.  The more we know about the disease and its ecology the better prepared we will be to face the challenges we may encounter during its eradication process.  Will we ever get to total world eradication of tuberculosis?  This writer thinks so but to quote the great Robert Frost it seems that “we have miles to go before we can sleep”.

1)      http://www.aphis.usda.gov/animal_health/animal_diseases/tuberculosis/

2)      http://www.cdc.gov/tb/publications/factsheets/general/mbovis.htm

3)      http://www.cdcnpin.org/scripts/tb/eliminate.asp

4)      http://www.cdc.gov/tb/statistics/default.htm

5)      http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5412a1.htm

6)      http://wwwnc.cdc.gov/eid/article/19/6/12-0543_article.htm

7)      http://www.cfsph.iastate.edu/Factsheets/pdfs/bovine_tuberculosis.pdf

8)      http://www.chop.edu/service/vaccine-education-center/a-look-at-each-vaccine/tuberculosis-vaccine.html

9)      http://www.mayoclinic.com/health/tuberculosis/DS00372/DSECTION=tests-and-diagnosis

10)  http://www.lung.org/lung-disease/tuberculosis/factsheets/multidrug-resistant.html

11)  http://www.ncbi.nlm.nih.gov/pubmed/20819249

12)  http://www.who.int/tb/publications/global_report/2011/gtbr11_full.pdf

13)  http://www.who.int/mediacentre/factsheets/fs104/en/index.html

14)  http://en.wikisource.org/wiki/Comprehensive_Tuberculosis_Elimination_Act_of_2008

15)  http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis

16)  http://en.wikipedia.org/wiki/Mycobacterium_avium-intracellulare_infection

17)  http://en.wikipedia.org/wiki/Tuberculosis

 

 

Climate change and public health

I rarely write about climate change. As much as it’s been hashed out amongst climate scientists, and even many of the former “climate skeptics” have now changed their tune, I readily accept that climate change is happening, and is happening largely due to human activities. More importantly for my field, climate change is also having effects on human health in a number of different ways, from the movement of insect vectors into new areas, to warming of the seas leading to more extreme weather conditions, to the loss of coral reefs and the freshwater that these reefs protect from the surrounding oceans. It’s an immense field, and it seems that every time I turn around, another paper is published detailing the public health effects of climate change.

Luckily for me, many of these examples have been carefully documented in a recent book by Paul Epstein and Dan Ferber, Changing Planet, Changing Health. Epstein was a maverick in this field, trained as a physician who had carried out global health research in several African countries. In his previous position helping to run the Center for Health and the Global Environment at Harvard, he led research into a variety of areas in tropical medicine, including the role of climate in disease epidemiology. Unfortunately, as I was finishing up this book last night, the New York Times reported that Dr. Epstein passed away at the age of 67. This is a huge loss to the field, but work in this area will certainly continue, and we’re likely to only see more connections between disease and global warming in the coming years and validation of his passions and ideas.

“Changing Planet, Changing Health” is deceptively expansive. It’s a mere 300 pages before notes and index, but it takes you on a journey investigating the movement of mosquitoes in Africa, cyanide in Honduras, soybean rust in Illinois, pine beetles in Colorado, and even flooding in Cedar Rapids, Iowa. And yet, the book never felt disconnected to me–Epstein & Ferber manage to draw the myriad climate-associated threads together into a well-woven tapestry, and fluidly move from one topic to another. They also discuss what needs to be done to curb this destruction in the last chapter.

Of course, the last chapter is also one of the toughest. While climate change is harming our health in a thousand different ways every day, there’s still denial in many circles that it’s even happening, and none of the solutions to curb it are easy. Furthermore, too many people still see it as “just a polar bear problem” rather than something that actually makes a difference in their lives. This needs to change. Epstein and Ferber succeed in making climate change personal: something everyone who eats and breathes should be concerned about.

“The Fever” by Sonia Shah

Malaria is one of mankind’s most ancient scourges. A century after the discovery of its cause, various species of the parasite Plasmodium, humanity still remains in its deadly grip in many areas of the world. Malaria is estimated to have caused 225 million illnesses and almost 800,000 deaths in 2009, making it one of the top infectious disease killers. Many of these deaths occurred in children under the age of five.

Shah traces the history of malaria from the introduction of the parasite into the human population to modern-day controversies about malaria treatment, research, and funding. It’s a fast-paced read; informative but never dry. Indeed, Shah makes much use of metaphor; sometimes, to the detriment of the scientific narrative, in my opinion. However, that’s more of a minor issue to me.

Shah begins the book with an anecdote about her own childhood as an American visiting her relatives in India; sleeping under a bed net while her cousins sleep in the open, fearing mosquitoes, and India, and being ashamed of her fears. She notes later that, when her family hears she is writing a book about malaria, they ask her why–to them, it seems as silly as writing a book about the common cold. Shah notes this several times throughout the book–for example, explaining that many in malaria-endemic regions, people would rather use their bednets for fishing than to protect from mosquitoes, so while programs which deliver such nets can tout high numbers of bednets distributed it doesn’t necessarily mean that everyone who receives one is using them correctly.

Indeed, much of the book is spent discussing the limitations and missteps of anti-malarial programs, past and present, from issues of mosquito resistance to pesticides, to parasite resistance to chemotherapy. Another repeated thread is political will, or lack thereof, in anti-malarial programs, and the ping-pong that is played by many funding agencies. When programs demonstrate success and malaria is reduced, there is little will to continue such programs–which may be hampered in any case by the emergence of resistant mosquitoes or parasites. It’s a messy business, and today’s programs don’t seem to be much better off than those carried out in the previous century.

Shah’s book is a thoughtful read for anyone interested in global health–not only for the history of Plasmodium‘s detection and eventual proof as the cause of malaria (after many false starts), but also for the thoughtful descriptions of global health programs carried out by outsiders throughout the decades, and possible ways to change these and avoid repeating the mistakes already made by predecessors.