Fasciola Hepatica Research Paper

In North Dakota and various other surrounding states have a very harsh climate compared to other places. Because of this, multicellular parasitic disease is an uncommon occurrence. Physicians in North Dakota and surrounding areas rarely if ever see and treat patients with parasitic diseases; however, it can happen and it is important to be informed about such diseases in order to better treat and inform patients. I myself was not informed about several parasites that can live in the area and would like to pass the knowledge onto my peers as well. The parasites I will focus on are Diphyllobothrium Latum and Fasciola Hepatica. In order to have a better understanding of the pathology of the two parasites, the following topics will need to be reviewed

for each parasite: 1. life cycle and morphology, 2. Diagnosis 3. Symptoms and treatments 4. Ways to avoid these various parasites.
Diphyllobothrium Latum
Diphyllobothrium Latum is a human parasite that can measure up to 30 feet and can live to be over 20 years old..CDC Diphyllobothrium, or fish tapeworm, is a cestode that can be found in various types of fish in the state of North Dakota and surrounding areas. Cestodes are a classification of parasites that refer to tapeworms.

Lifecycle and Morphology
The parasite Diphyllobothrium Latum has a complex lifecycle. Unembryonated operculated eggs are released in fecal matter by infected individuals. These eggs are very durable and can spend up to 20 days in the open environment. Once in water, these eggs embryonate and hatch in the environment. During this the operculum of the egg opens and the oncosphere for of the parasite is released into the aquatic environment. The oncosphere is encapsulated in a membrane with cilia to allow for movement. Together it is called coracidium and is the first larval stage in the life of Diphyllobothrium Latum. In the next step of the lifecycle, these coracidium move in the water and wait to be eaten by various kinds of small crustaceans. Once the coracidium are eaten by the crustacean, the first intermediate host. Once the coricidium are ingested they travel through the stomach and to the intestines of the crustacean and borrow through the wall into the gut to develop into the procercoid, the second larval form. This appears as a very small worm-like form. The procercoid then wait until the crustacean is eaten by a smaller fish. This is normally sometime type of baitfish such as a minnow. The procercoid larva are then released from the ingested crustaceans and migrate to various tissues of the fish in order to develop into plerocercoid which is the third and final larval stage of the parasite. This is the only larval form of the parasite that is infective to humans; however, humans normally do not ingest minnows. The infected minnows are generally eaten by larger predatory fish such as northern pike, walley, and perch. The plerocercoids are then released and further develop and multiply in the tissue of the predatory fish. The plerocercoid may form cysts within the muscle of the predatory fish. Humans are the main or definitive host of Diphyllobothrium Latum. The Plerocercoids are transferred to humans when they eat raw or undercooked fish. The plerocercoid form of the parasite then travels through the digestive tract to the small intestine where it develops into an adult. There is some terminology about the morphology of the adult parasite that you should be aware of. The head of the adult worm is called the scolex. The head of Diphyllobothrium Latum is made up of two bothria. Bothria are muscular grooves that allow the parasite to attach onto the wall of the small intestine. The way of attachment can vary from parasite to parasite. Diphyllobothrium Latum is made up of a segmented body that is called the strobili. Within that each individual segment is called a proglottid. A proglottid in Diphyllobothrium Latum contains both male and female reproductive organs, therefore, only one worm is needed to reproduce. The morphology and lifecycle are important to know in order to identify the parasite and hot the patient became infected.
Diagnosis
Diagnosing some parasites can be very difficult. Typical fecal samples will be taken from the patient. The reasoning to take these fecal samples is to see if any eggs or parts of the parasite are being expelled in order to identify the parasite and correctly treat it. Once taken samples can be examined. The first way of examining the sample is to simply looke to see if anybody parts of the parasite that can identified such as the scolex, proglottid, or groups of proglottids.HUMAN INFECTION If the head of a parasite in doing this, it can be examined to see what way it attaches to the host which can narrow down the number of possible parasites considerably. If nothing is found during an eye examination then microscopic examination. The purpose of this is to find eggs which are too small to be seen with the naked eye. The first way to do this is to simply smear a sample on a slide and examine it under a microscope; however, in this method it can be difficult to identify eggs because of the amount of debris on the slide. Often times either a sedimentation or flotation method will be used to help concentrate the eggs and remove debris. In sedimentation, liquids with varying densities are used to separate out layers of particles. The top layers are removed leaving only what has collected in the bottom of the tube which should be concentrated with eggs making them easier to identify. In flotation the same principle is used; however, in this method eggs float to the top and a sample can then be taken and examined. It is possible to not find eggs when using this method. For this reason, many times multiple fecal samples are taken. Once part of the parasite has been identified, a polymerase chain reaction is used to confidently identify the organism. 18s rRNA is identified and amplified in this reaction. Once amplified it is then sent to B.L.A.S.T for identification.MOLECULAR ID Once identified the parasite can then be treated accordingly and the patient can then be more informed about the symptoms, treatment, and ways to avoid the parasite.

Symptoms and Treatment
Infections of Diphyllobothrium Latum can be asymptomatic. According to United States National Health Institute, “...about one out of five infections, diarrhea, abdominal pain, or discomfort occurs…”. Other symptoms of this parasite include: headache, B12 deficiency, fatigue, and anemia. MV CPP In cases where there is a large infection of Diphyllobothrium Latum, the amount of worms can obstruct the intestines. Treatment of Diphyllobothrium Latum is very simple. It is one single does of praziquantel which is taken orally in the form of a 25 milligram pill. This then kills the adult worms which are excreted out of the body in feces.
Ways to Avoid Diphyllobothrium Latum
In order to avoid Diphyllobothrium Latum completely, avoid all fish that you suspect is raw, pickled, or undercooked in any way. In order to destroy any possible parasites, fish should be cooked to one hundred and forty degrees Fahrenheit or frozen at zero degrees Fahrenheit for two days. By doing this, any possible larva that are on or in the fish are dead and safe for human consumption. Diphyllobothrium Latum is uncommon in the United States, but much more common across Europe and Asia. There are several examples of this. In parts of Russia near the Okhostk Sea the parasite is seen to infect roughly one to three and a half percent of the populations.NCBI A second example is that in parts of central and western Europe roughly five to nine and a half perch fillets are contaminated with Diphyllobothrium Latum.NCBI This information is important and extremely useful knowledge for anyone who is traveling outside of the United States to be weary of any dishes with raw fish. The point of this is not to scare, but rather to inform the general population about the possible health risks associated with raw fish.
Fasciola Hepatica
Fasciola Hepatica, more commonly known as the liver fluke, is most commonly found in areas of Scotland and Ireland, but is known to be distributed throughout the world.

Fasciola Hepatica is parasite that is classified as a trematode. The life cycle of Fasciola hepatica, like Diphyllobothrium Latum, is quiet complex. Once again, unembryonated eggs start by being passed on by a definitive host such as a human, cow, sheep, or goat. The egg is durable and waits to be in an aquatic environment. Once in the aquatic environment, a miracidium hatches from the egg. The miracidium is the first ciliated larval stage of this parasite. The purpose of the miracidium is to seek out and penetrate a fresh water snail. Once the miracidium penetrate the skin of the snail, they migrate into the muscle. In the muscle, miracidium transform into sporocysts which then reproduce asexually. The sporocysts mature into redia and then into cercariae. The maturation process of the parasite in the snails typically takes five to seven weeks.CDC The tailed cercariae are then released from the snail and seek out aquatic vegetation. Once the cercariae find aquatic vegetation it encysts, or form a cyst, in the plant tissue and matures into a metacercariae. During this, the cercariae loses its tail to become non-motile and forms a very hard thick wall in the plant tissue in order to survive. This is the only larval form of the parasite that is infective to humans as well as other definitive hosts. Humans then become infected when they eat the aquatic vegetation such as watercress with the encysted metacercariae on it. When this happens the encysted parasite travels to the duodenum outside of the stomach in the small intestines and excysts, or breaks out of its cyst. The metacercariae then borrow through the lining of the small intestine into the peritoneal cavity and migrate to the liver, more specifically to the bile ducts of the liver. Once in the bile ducts the metacercariae mature into adult

worms. The maturation sequence of Fasciola Hepatica can take up to three to four months in humans. Once completely mature adults can measure up to thirty millimeters in length and thirteen millimeters wide. CDC
Diagnosis
The diagnosis of Fasciola Hepatica is almost identical to that of Diphyllobothrium Latum. The same procedures and techniques are used. One difference is that with Fasciola Hepatica eggs can also be found from bile samples. First fecal samples are taken and are examined by eye to see if any parts of the parasite can be found. If not then microscopic techniques must be used. Smears are taken and reviewed and if nothing is found either the flotation or sedimentation method is used to concentrate possible eggs. Once pieces of the parasite are found, 18s rRNA is amplified using polymerase chain reaction and then sent in for identification of the parasite. In Fasciola Hepatica, eggs can be difficult to find because not many are produced by the parasite. More often medical staff rely on blood tests in order to help identify the infection. In blood tests, medical staff look for antibodies which the parasite causes the body to produce.
Symptoms and Treatment
Now that the life cycle and diagnosis of Fasciola Hepatica are understood thoroughly, discussion can begin on the pathology of the parasite. The disease that Fasciola Hepatica causes is split into two different phases: an acute phase and a chronic phase. The acute phase of the disease is when the metacercariae are migrating to the bile ducts. According to the Centers for Disease Control and prevention, in this portion of the disease symptoms include: “gastrointestinal problems such as nausea, vomiting, and abdominal pain/tenderness. Fever and rash may also occure.”CDC These symptoms are caused by the body’s immune response to the metacercariae migrating to the bile ducts. The chronic phase is the duration of the adult worms life once it becomes established in the bile ducts of the host. During the chronic phase of the disease symptoms can be more discrete. The Centers for Disease Control and Prevention list the symptoms of the chronic disease to include:” reflecting inflammation and blockage of bile ducts, which can be intermittent. Inflammation of the liver, gallbladder, and pancreas also can occur.” CDC The treatment for Fasciola Hepatica is simple much like Diphyllobothrium Latum. It involves one to two doses of triclabendazole to kill the worms and remove them from humans.
How to Avoid Fasciola Hepatica
You cannot ensure that all of your aquatic vegetation will be parasite free; however, you can ensure that you will never become affected by the parasite. One simple way is to avoid eating aquatic plants, but this is irrational. A much simpler option is to lways cook your aquatic vegetation thoroughly and avoid areas that are known to have this parasite in its waters. If someone is in an area where this parasite is known to live, then try to avoid eating copious amounts of aquatic vegetation. For any meat obtained from animals in the area, thoroughly cook the meat to kill any possible parasites
In conclusion, I recommend that all staff here at Park River Health Center do their own research into various local parasites. These are only two aquatic parasites that may inhabit local lakes and streams. Parasitic disease is uncommon in North Dakota and the surrounding areas; however, medical professionals need to be aware of all diseases that we may encounter. The point of this is not to scare individuals, but rather to inform the public of the possible parasites.