The human body is comprised of an abundance of microorganisms that are considered part of our normal and healthy microbiota.8 Most of these microorganisms are typically not injurious, but under certain conditions or when a patient is immunocompromised, some microorganisms may produce infectious diseases.7 Infectious diseases are ailments caused by the opportunistic pathogens already present in our bodies or other harmful microorganisms that were acquired from traveling, hospitals, outdoors, or encountering another infected human.8 According to Woolhouse and Gowtage-Sequeria, there are 1,407 recognized species of human pathogen, 58% of which are zoonotic and 177 are regarded as emerging or reemerging.
13 The leading public health institute is the Centers for Disease Control and Prevention (CDC) and they are responsible for securing and progressing the health of the public by researching known and identifying new infectious diseases, preventing and regulating the spread of infectious diseases, providing accurate information to healthcare communities and to the general public, and implementing strategies to reinforce our public health system.3 Infectious diseases play a crucial role in public health because without the knowledge and analysis of them our population would not have the proper information to assure their health and our healthcare communities would not know what precautions to take when treating a patient with an infectious disease.3 According to the CDC, some of the major infectious diseases world-wide are tuberculosis, malaria, AIDS, hepatitis B, hepatitis C, meningitis, and schistosomiasis.3 The disease this case study will discuss is the Ebola virus disease (EVD), earlier known as Ebola hemorrhagic fever.
According to the World Health Organization (WHO), EVD has an incredibly high risk of death, killing between 25-90% of people infected and because the natural reservoir host of EVD has not yet been identified, the way in which the virus first develops in a human at the beginning of an outbreak is undiscovered however, scientists suspect humans are infected by coming into contact with an infected animal or their bodily fluids such as a fruit bat or primate.11 After the initial contact, the virus is further spread through direct contact via breaks in skin or other mucosal surfaces.11 This virus belongs to the family Filoviridae and contains five different species, but only three of them correlate with the considerable outbreaks in Africa. Those three species are: Bundibugyo ebolavirus, Zaire ebolavirus, and Sudan ebolavirus.11 This case study focuses mainly on the species Zaire ebolavirus because it is the deadliest.
Biography
The patient is a 37-year old Australian white male, Ethan Williams, residing in Northmead, New South Wales, Australia with his wife of 5 years. His wife, Zoe Williams, is a 34-year old Australian who previously resided in Sydney before moving to Northmead with her husband. Zoe is a writer for a popular travel magazine based out of Sydney and attended the University of Sydney where she met Ethan. Zoe obtained her Bachelors in Journalism and ended up having a couple of classes with Ethan her sophomore year of college. Ethan is a professional photography journalist who is employed by National Geographic and generally travels to many different countries all over the world. He graduated from the University of Sydney with a Bachelors of Photography and a minor in Journalism. He is an extremely adventurous and curious person and thoroughly loves to explore the outdoors. In addition to exploring, Ethan also enjoys camping, hiking, diverse culture, astronomy, cooking, and trying new foods. When he travels to different countries for work he often likes to do his own research to discover unique destinations to hike, photograph, and explore during his free time. He also likes to spend time with the natives and discover the best places to try all the ethnic foods of all the different destinations he travels to. Zoe equally enjoys the same hobbies as Ethan does and when she has free time she loves to travel with him on his business trips. Ethan has one younger sister who lives on the other side of Australia in Perth with their parents. He is extremely close to his sibling and parents, but all his travel makes it difficult to see them as often as he would like. Ethan and Zoe do not have any pets or children because of all the traveling they do, but they definitely want to start a family in the future.
Case Summary
Ethan recently traveled to West Africa, Sierra Leone to be exact, for a job assignment with National Geographic. He took the necessary precautions prior to his trip and went to his local clinic to get travel vaccinations. Ethan’s main assignment was to photograph African wildlife in their natural habitat and while he was exploring different areas of Sierra Leone he came across a cave that naturally piqued his interest. Ethan was highly successful in completing his task of photographing wildlife for his article submission sooner than he expected and he used his extra time to explore the cave that he came across earlier. Ethan managed to get a few nicks and scrapes while hiking and climbing up to the cave, but because he was so excited and anxious to explore the cave he did not pay much attention to it. Once he reached the cave he began to take several pictures of the exterior and finally made his way inside.
Ethan only had a small flashlight that was bright enough to show the pathway just a couple steps ahead of him so he did not realize this cave was inhabited with fruit bats. As he got deeper and deeper into the cave he noticed that the interior of the cave had intriguing rock formations and wanted to photograph them, but as he began taking pictures the flash on his camera startled some of the fruit bats and a few of them began franticly flying around and to avoid coming into contact with them, Ethan fell to the floor and began crawling towards the exit of the cave. Ethan did not realize the floor was covered in bat urine and feces and that his small nicks and scrapes were infected by it. Ethan flew home the next morning and was happily welcomed by Zoe. Ethan did not notice anything odd with his body until four days after returning home when he began to experience severe headaches, muscle pain, a low-grade fever of 37.6C, and weakness. Zoe suggests that he is probably just worn out from his trip or maybe got a bug on the plane and recommends that he gets some rest. On the 6th day, his symptoms are still present, feels increasingly weakened, and his fever reaches 38.3C and decides to take home remedies and returns back to bed.
The next day he feels slightly worse so he has Zoe take him to their local urgent care to be examined. His nurse takes his vitals and chief complaint and relays it to the physician. Zoe explains that he returned home from a business trip a week ago and probably caught a bug on the flight and without asking where he traveled to the physician agrees and suggests OTC medications and plenty of fluid and rest and sends Ethan home. On the 10th day, Ethan wakes up with red eyes and begins to complain about abdominal pain. Later that morning, he is beginning to vomit and presents with bloody diarrhea and Zoe helps to clean up after him because he did not quite make to the restroom when the first incident occurs. Zoe also notices a rash spreading from his chest to his stomach and suggests that they go to the hospital after she returns home from work. Zoe returns home from work only to find Ethan unconscious in their bed. She also observes bleeding from his nose and mouth and immediately calls the ambulance.
Differential Diagnosis
EVD can be troublesome to differentiate from other infectious diseases because most of the early symptoms are mild and nonspecific. As reported by the CDC, Ebola virus is commonly mistaken for malaria, typhoid fever, fungal meningitis, and shigellosis.3 Ethan initially presented with fever, muscle pain, and headaches which are common symptoms of the potential pathogens listed above. As his symptoms worsened and new ones became visible, the exact culprit became much easier to identify. Aside from the common symptoms, Ethan traveling to West Africa was another factor that contributed to the possibility of other potential pathogens. Salmonella typhi, also known as typhoid fever, and Shigella should be considered as a potential pathogen because it exists as a significant health threat in underdeveloped countries like Africa, where Ethan just visited.11 Shigella causes shigellosis, a form of food poisoning, which is typically linked to diarrhea, vomiting, and abdominal pain which are all symptoms Ethan was experiencing.
3 Food poison is also more prevalent in developing countries like Africa because it is not very industrialized so you have a higher chance of coming into contact with contaminated food and water. Aside from that, Ethan is big on experiencing different foods so it can be assumed that he consumed contaminated food products. Another potential pathogen that should be considered is Cryptococcus, which causes fungal meningitis. This disease is one of the most common causes of adult meningitis in Africa and is thought to be transmitted by inhaling soil contaminated with bird droppings.3 Cryptococcus makes complete sense because Ethan recently traveled to Africa and he may have inhaled soil contaminated with bird droppings while exploring Sierra Leone and photographing all the wildlife, including birds. Finally, malaria can be considered a potential pathogen because traveling to sub-Saharan Africa has the greatest risk of getting malaria and the symptoms of malaria are similar to those of EVD.3 The primary reasons why all the above pathogens should be considered is due to common symptoms, common place where they can be contracted, and under development of the country.
