Digestive System Pt. 2 Flashcards
What is the most unique symptom seen with viral hepatitis?
Jaundice
What actually causes the liver damage seen with viral hepatitis?
Host immune response
What is unique about the onset of symptoms of viral hepatitis?
Symptoms may occur years after initial infection
What are the pathogens responsible for viral hepatitis?
Hepatitis A virus, Hepatitis B virus, Hepatitis C virus, Hepatitis delta virus, Hepatitis E virus
What is unique about Hepatitis A virus’s survivability?
Can survive on various surfaces and is resistant to common household disinfectants
Does Hepatitis A cause chronic liver disease?
No
How is Hepatitis A transmitted?
Fecal-oral route
Which hepatitis viruses have a vaccine?
A and B
Hepatitis B has mild symptoms, if any, but what is its serious issue?
Can cause severe liver damage
A Hepatitis B infection coinfecting with what other virus increases the risk of permanent liver damage?
Hepatitis D virus
Which hepatitis virus is associated with liver cancer?
Hepatitis B virus
How is Hepatitis B spread?
Infected needles, sexual intercourse, passage to babies during childbirth
What are the symptoms like of Hepatitis C?
Few, if any, symptoms but a chronic infection
What serious issues can occur overtime with Hepatitis C?
Liver damage and liver failure
How is Hepatitis C spread?
Needles, organ transplants, blood transfusions, sexual activity
Hepatitis D virus is dependent upon which other virus?
Hepatitis B virus
Why is Hepatitis D virus dependent upon Hepatitis B virus?
Hepatitis D virus cannot attach to liver cells (called a satellite virus)
Hepatitis D plays a role in triggering what serious condition?
Liver cancer
How is Hepatitis D transmitted?
Bodily fluids (sexual activity and contaminated needles)
What is another name for Hepatitis E?
Enteric hepatitis
Hepatitis E has a fatality rate in 20% of what population?
Pregnant women
How is Hepatitis E transmitted?
Fecal-oral route
Where has the vaccine for Hepatitis E been approved?
China in April of 2012
How is hepatitis diagnosed?
Initially by jaundice, enlarged liver, or ascites but officially by serological testings
What are the most common forms of hepatitis?
B and C
How can hepatitis be prevented?
Good hygiene and protected sex/abstinence
What is another name for Giardiasis?
Beaver Fever
What is unique about the stools with Giardiasis?
Rotten egg smelling
What pathogen is responsible for Giardiasis?
Giardia intestinalis (aka G. lamblia, G. duodenalis)
Where is Giardia intestinalis naturally found?
Intestinal tracts of animals and in the environment
What kind of disease of Giardiasis?
Protozoan
What is one of the most common waterborne gastrointestinal diseases in the U.S. discussed?
Giardiasis
How is Giardiasis acquired?
Ingesting cysts in contaminated water or when swimming
Can water containing cysts that could cause giardiasis be inhaled?
Yes, only an issue when ingested
What group is particularly at risk for developing giardiasis?
Hikers and campers and their pets because wild animals shed Giardia into mountain streams
How can giardiasis be prevented?
Humans nor pets should drink unfiltered stream or river water
If infected with giardiasis, what activity should be avoided?
Swimming to ensure no parasites are shed into the water
What is another name for Cryptosporidiosis?
Cryptosporidium enteritis
How long can diarrhea last with Cryptosporidiosis?
Up to 2 weeks
What pathogen is responsible for Cryptosporidiosis?
Cryptosporidium parvum
How is Cryptosporidiosis acquired?
Drinking contaminated water or sometimes fecal-oral transmission (ex. day care)
What kind of amebiasis is asymptomatic and represents 90% of all cases?
Luminal amebiasis
What kind of amebiasis causes severe diarrhea, colitis, and can also lead to apendicitis?
Invasive amebic dysentery
What kind of amebiasis causes necrotic lesions in the liver, lungs, spleen, kidneys, or brain?
Invasive extraintestinal amebiasis
What pathogen is responsible for amebiasis?
Entamoeba histolytica
How is amebiasis acquired?
Ingestion of cysts through contaminated food/water, hands, or oral-anal intercourse
In what areas is amebiasis more prevalent?
Where human feces is used as fertilizer and water purification is inadequate
What pathogen is responsible for Cyclosporiasis?
Cyclospora cayetanensis
How is Cyclosporiasis acquired?
Ingestion of oocysts in contaminated food or drink
Outbreaks of Cyclosporiasis has been linked to what food that is imported from Central and South America?
Raspberries
What is the treatment for cyclosporiasis?
Combination drugs for 7 days
How can cyclosporiasis be prevented?
Washing fruits and vegetables to prevent infection or cooking/freezing to kill oocysts
What is unique about the symptoms of tapeworm?
Usually asymptomatic but weight loss is generally visible
What serious condition can result if a tapeworm is exceptionally large?
Intestinal blockage
What pathogen is responsible for beef tapeworm?
Taenia saginata
What pathogen is responsible for pork tapeworm?
Taenia solium
How is tapeworm acquired?
Consumption of raw or undercooked meat containing cysts
How is tapeworm diagnosed?
Presence of proglottids in fecal sample
What is the name of the tapeworm derived from fish?
Diphyllobothriasis
What is unique about the symptoms of diphyllobothriasis?
80% of cases are asymptomatic and can go years without being detected
In a small number of cases, what deficiencies can result from fish tapeworm?
Vitamin B12 deficiency and megaloblastic anemia
What pathogen is responsible for fish tapeworm?
Diphyllobothrium latum
Diphyllobothrium latum is native to what locations?
Scandinavia, Russia, and the Baltics (but now is present in North America)
How is diphyllobothriasis acquired?
Consumption of raw or undercooked freshwater fish like walleye pike, salmon, trout, minnows, or perch
Canine tapeworm larvae travel throughout the body and produce what structures?
Hydatid cysts (can calcify and enlarge to the size of a grapefruit)
In what organ are hydatid cysts usually formed by canine tapeworm larvae?
Liver
What pathogen is responsible for canine tapeworm?
Echinococcus granulosus
How is canine tapeworm diagnosed?
X-ray, MRI, CT for presence of calcifications
How is canine tapeworm treated?
Surgery to remove cysts, antihelminthic drugs
How can ascariasis be lethal?
Complete intestinal blockage possible
What kind of pulmonary signs can be seen with ascariasis?
Dry cough, difficulty breathing, blood sputum
What pathogen is responsible for ascariasis?
Ascaris lumbricoides
What is the largest nematode known to infect humans?
Ascaris lumbricoides (as large as 30cm/12in in length)
Where is ascariasis endemic in the U.S.?
Rural southeast
What is the most common nematode infection of humans worldwide?
Ascariasis
How are eggs of Ascaris lumbricoided ingested by humans?
In water or on vegetables
How is ascariasis diagnosed?
Eggs in stool, larvae in sputum, or adult worms passed in stool or exiting via nose/mouth
When is surgery required in treating ascariasis?
If intestinal blockage occurs
What deficiencies can result from hookworm?
Anemia, iron, and protein deficiencies from the adult worms sucking the blood of the host
What reaction occurs at the site of larvae penetration of hookworm?
Ground itch
What types of hookworm can infect humans?
Ancylostoma duodenale
Necator americanus
On what location of the body do hookworm larvae usually penetrate the skin during transmission?
Foot
What is the second most common nematode affecting humans worldwide?
Hookworm (Ancylostoma duodenale and Necator americanus)
How can hookworm be prevented?
Wearing shoes in endemic areas
What is the characteristic symptom/sign of pinworm?
Perianal itching
What is the pathogen responsible for pinworm?
Enterobius vermicularis (nematode)
Pinworm usually affected what population?
Children
When are pinworm eggs deposited in the perianal region?
At night
How can pinworm be spread?
On bedding and person-to-person contact after scratching
What is the most common parasitic worm infestation in the U.S.?
Pinworm
What is another name for Dracunculiasis?
Guinea worm disease
After about a year of infection, the worm involved with Dracunculiasis forms a blister that breaks open on what area of the body?
Usually the foot
What is the pathogen responsible for Dracunculiasis?
Dracunculus medinensis
How do humans acquire dracunculiasis?
Drinking unfiltered water containing copepods (small crustaceans) that have been infected with Dracunculus medinensis larvae
Where is dracunculiasis typically found?
Africa and India
What is the treatment for dracunculiasis?
Winding the worm out on a stick over a period or hours to weeks
What symbol is associated with dracunculiasis?
The Rod of Asclepius, a modern symbol of medicine
What is another name for trichinosis?
Trichinellosis
What kinds of symptoms are presented with trichinosis?
Muscle pain and weakness
How does trichinosis infect the body?
Trichinella larvae encased in a cyst is swallowed, digestive juices dissolve the cyst, and the parasite is released into the intestines and enter the bloodstream
What is the pathogen responsible for trichinosis?
Trichinella spiralis
How do humans become infected with trichinosis?
Eating undercooked meat containing cysts of T. spiralis (especially pork)
Why is trichinosis uncommon in the U.S.?
Food regulations (USDA approved meat is okay)