GI Exam 2 (not finished dont download yet) Flashcards
Riovirus Family
lab tests
A Race on the Rio
- NEG** sense _D_S RNA**
- DS! DS! DS! (Only RNA DS in sketchy!)
- NAKED virus
- avg of 11 Segments, 9-12 (B.O.A.R. mnemonic)
Rotavirus (a Riovirus)
key facts
A Race on the Rio
- Fecal-oral transmission
- Toxin mediated (NSP4 enterotoxin) secretory diarrhea.
- NSP4 ↑ Cl- permeability → secretory diarrhea that is explosive and watery (like norovirus, think Rotavirus sounds like rotate propeller).
- Classic outbreaks are in winter!
- Children most at risk (infants, daycare, etc).
- #1 cause of severe diarrhea in young children!
Colorado Tick Virus (a Riovirus)
key facts
A Race on the Rio
- Colorado Tick Virus
- Symptoms include myalgia, fever, and vomiting.
- NO rash !!!
- ddx from Rocky Mountain Spotted Fever due to lack of a rash with Colorado Tick Virus.
Rotavirus (a Riovirus)
Treatment
A Race on the Rio
Supportive care and oral rehydration
Rotavirus (a Riovirus)
Vaccine
A Race on the Rio
- Live attenuated oral vaccine
- 1st dose given before 3 months of age due to:
- Decreased efficacy
- May increase risk of intussusception*
* (stimulation and enlargement of peyers patches → which then act as lead points for the intestine to telescope into itself → can cut off blood supply → and possible bowel perforation.
Calicivirus
replication MOA
Cali Sea Cruise
Naked POS** sense _R_NA**
Calici produces one long single protein that is cleaved by viral proteases into smaller active constituents. (like Picornaviruses!!!)
Replicates in the cytoplasm like all POS sense RNA.
Calicivirus
signs and symptoms
Cali Sea Cruise
- Most common strain of Calicivirus is NOROVIRUS (Norwalk virus)
- Calici is commonly acquired by people in closed quarters like cruises (90% of all diarrhea outbreaks on cruises!) and day care.
- Also acquired from shellfish or places where food is touched by people (buffets!)
- Explosive diarrhea!!!
Adenovirus
lab tests
A Den-O lions
DS DNA
Naked virus (No envelope!)
Adenovirus
Source
A Den-O lions
- Transmitted by respiratory droplets and fecal-orally.
- Most at risk are little children**, **military recruits, and public pools.
Adenovirus
signs and symptoms
A Den-O lions
3 major disease processes:
- Tonsillitis (most common cause of infection in adenoids and tonsils).
- Hemorrhagic cystitis*
- Viral conjuctivitis aka “Pink Eye“ (common cause)
* DDX BK Virus (a Polyomavirus) which also has hemorrhagic cystitis, but is more common in immunocompromised (transplant pts, or pts with AIDS)
Adenovirus
Vaccine
A Den-O lions
Military** recuits get a **live vaccine
Entamoeba histolytica
lab tests
Entering the Historical Dig
Flask shaped ulcers along the colon
Bloody stool
Stool O&P (ova and parasite exam) looking for cysts or trophozoites will contain trophozoites that contain endocytosed RBC’s.
Elisa antigen test on stool or serum.
Entamoeba histolytica
2 main life cycle stages
Entering the Historical Dig
- Cyst form is infectious and is ingested from contaminated water. Gay men can get the disease from anal oral transmission.
- Trophozoite** form invades** the colon, spreads via portal circulation into the liver.
Entamoeba histolytica
signs and symptoms
Entering the Historical Dig
- RUQ pain w/ enlarged and tender liver.
- Right lobe is the most commonly involved site of amoebic liver abscesses.
- Puss inside abcess have “anchovy” paste consistency.
- Intestinal amebiasis
- Flask shaped ulcers along the colon.
- Bloody stool
Entamoeba histolytica
Treatment
Entering the Historical Dig
Metronidazole
Can be taken with a lumenal agent like:
Paramycin or Iodoquinol
* DDX Entamoeba which you treat without removing surgically vs. Echinococcus which has a liver mass that you do remove surgically.
Giardia Lambia
lab tests
Giardia Jungle Ride
Foul smelling Steatorrhea (fatty diarrhea)
Stool O&P (ova and parasite exam) looking for cysts or trophozoites show trophozoites that are flagellated with ventral sucking discs.
Elisa antigen test on stool
Deficient in Vit. A,D,E,K
Giardia Lambia
2 main life cycle stages
Giardia Jungle Ride
- Cysts from feces contaminates water, and infects travelers, backpackers, or campers who drink unfiltered or unpurified water.
- Trophozoites attach to but do not invade intestinal walls, so only cause diarrhea.
Giardia Lambia
Treatment
Giardia Jungle Ride
Metronidazole
Giardia Lambia
signs and symptoms
Giardia Jungle Ride
Bloating, flatulence, and foul smelling diarrhea.
Steatorrhea (fatty diarrhea) due to excessive mucous production that impairs the absorption of the intestine (A,D,E,K will be deficient).
Cryptosporidium
lab tests
Tales from the crypt
Unicellular partially acid fast.
Under staining looks like amethyst in water.
Cysts contain 4 motile sporozoites.
Profound watery diarrhea.
Cryptosporidium
2 main life cycle stages
Tales from the crypt
- Oocysts are infectious, released fecally, and absorbed orally. Highly resistant to chlorination, but can be removed via filtration.
- Cysts contain 4 motile sporozoites that will attach to the small intestine wall and cause damage.
Cryptosporidium
signs and symptoms
Tales from the crypt
Profound watery diarrhea
* Most common cause of diarrhea in AIDS patients!
Cryptosporidium
Treatment
Tales from the crypt
- Nitazocanide tx for immunocompetent
- Spiromycin (not FDA approved in US)(a macrolide antibiotic)
- Supportive care
Enterobius vermicularis (pinworms)
Intestinal nematode (round worms)
source / signs and symptoms
Super Worms!!! (In Nematode City)
Female pinworms migrate to the anus and lay eggs → causes itching → fecal oral transmission can reinfect if touch mouth after scratching anus.
Ancyclostoma duodenale and Necator americanus (hookworms)
Intestinal nematode (round worms)
source / signs and symptoms
Super Worms!!! (In Nematode City)
- Hookworms found in rural southern US
- Walk barefoot** → Enter _blood_stream** → Larvae go to lungs → ascend bronchiole tree → get coughed up → swallowed, then enter and mature in the intestine. (feet→blood→lungs→GI)
- Pt can develop severe iron deficiency anemia.
Ascaris lumbricoides (Giant large worm)
Intestinal nematode (round worms)
source / signs and symptoms
Super Worms!!! (In Nematode City)
- Ingest eggs from contaminated food or water → migrate to lungs through gut wall and bloodstream → come back to gut to become adults → go into feces (GI→blood→lungs→GI)
- Malnutrition and respiratory symptoms (most likely intestinal nematode to cause resp. sympt.)
- Intestinal obstruction at ileocecal valve (major complication!)
Enterobius vermicularis (pinworms)
Intestinal nematode (round worms)
lab tests / tx
Super Worms!!! (In Nematode City)
Scotch tape test on anus → eggs will stick to tape → visible on microscope.
tx with Pyrantel pamoate and Albendazole
Ancyclostoma duodenale and Necator americanus (hookworms)
Intestinal nematode (round worms)
lab tests / tx
Super Worms!!! (In Nematode City)
- Look for eggs in stool.
- High eosinophil count (eosinophilia).
- tx with Pyrantel pamoate and Albendazole
Ascaris lumbricoides (Giant large worm)
Intestinal nematode (round worms)
lab tests / tx
Super Worms!!! (In Nematode City)
- Look for eggs in stool
- High eosinophil count (eosinophilia).
- tx with Albendazole*
*(Albendazole causes microtubule dysfunction to make worms immobile. Dont give microtubule inhibitors to pregnant women. If pregnant give Pyrantel pamoate)
Strondyloides stercoralis (Thread worm)
Intestinal nematode (round worms)
source / signs and symptoms
Super Worms!!! (In Nematode City)
- Penetrate skin on bottom of feet → then goes to lungs → then GI tract → AUTOINFECTION of host by laying eggs** on **intestinal wall! (feet→blood→lungs→GI→GI→GI...)
- If immunocompromised can lead to hyper infection.
Strondyloides stercoralis (Thread worm)
Intestinal nematode (round worms)
lab tests / tx
Super Worms!!! (In Nematode City)
- Eggs DONT get passed to stool so only find larvae in stools.
- High eosinophil count (eosinophilia).
- tx with Albendazole* and Ivermectin
*(Albendazole causes microtubule dysfunction to make worms immobile. Dont give microtubule inhibitors to pregnant women. If pregnant give Pyrantel pamoate)
Trichinella spiralis (Trichina worm)
Intestinal nematode (round worms)
source / signs and symptoms
Super Worms!!! (In Nematode City)
- Found in undercooked meat, commonly pork or bear.
- Larvae get into blood → go systemic → form cysts in striated muscle cells (GI→blood→systemic→striated muscle cells)
- Periorbital edema
- Vomiting and fever
- Inflammation of muscle → severe myalgia
Trichinella spiralis (Trichina worm)
Intestinal nematode (round worms)
lab tests / tx
Super Worms!!! (In Nematode City)
- Most often diagnosed by a Trichinella antibody test. In some cases a muscle biopsy may be performed.
- High eosinophil count (eosinophilia).
- tx with Albendazole*
*(Albendazole causes microtubule dysfunction to make worms immobile. Dont give microtubule inhibitors to pregnant women. If pregnant give Pyrantel pamoate)
Eosinophil
WBC
w/ little pink granules
& bilobed nuclei
Dracunculus medinesis (Guinea worm)
Tissue nematode (round worms)
source / signs and symptoms
Screamatodes III: Return of the flesh eaters
- Transmitted by ingesting water contaminated with copepods (small crustaceans) containing larvae
- Painful skin ulcer
- Worms (adult female) coming out of the skin!
Dracunculus medinesis (Guinea worm)
Tissue nematode (round worms)
lab tests / tx
Screamatodes III: Return of the flesh eaters
- Diagnosed via worms (adult female) coming out of the skin!
- Peripheral eosinophilia
- Pull out by spinning matchsticks or pencil slowly over several days.
- Metronidazole will help speed up the process (but not cure it)
Onchocerca volvulus (Filaria worm)
Tissue nematode (round worms)
source / signs and symptoms
Screamatodes III: Return of the flesh eaters
- Found around rivers in Africa, C. america and S. America
- Black fly bites human host → larvae burrow down into the hosts skin → make micro filarial that come back out, starting as scattered puritic papules → making hyper and hypo pigmented spots. (Hypo usually on shins of older patients)
- River blindness!!! 2nd leading cause of blindness after Trachoma (Chlamydia)
Onchocerca volvulus (Filaria worm)
Tissue nematode (round worms)
lab tests / tx
Screamatodes III: Return of the flesh eaters
- Eosinophilia
- Microfilaria on skin biopsy under microscope.
- Tx with Ivermectin
Wucheria bancrofti (Thread worm)
Tissue nematode (round worms)
source / signs and symptoms
Screamatodes III: Return of the flesh eaters
- Mosquitos are intermediate host → bite human and deposit larvae on skin → which enter the lymph system → lymphadenopathy
- Elephantiasis (From long standing lower extremity lymphodema)
- Microfilaria travel to the lungs and cause hypersensitivity rxn
Wucheria bancrofti (Thread worm)
Tissue nematode (round worms)
lab tests / tx
Screamatodes III: Return of the flesh eaters
- Organisms can be seen on thick blood smear
- Eosinophilia
- Tx with Diethylcarbamazine
Toxicara canis (Dog roundworm)
Tissue nematode (round worms)
source / signs and symptoms
Screamatodes III: Return of the flesh eaters
- Transmitted by ingestion of food contaminated with dog or cat feces containing the eggs.
- Parasitic larvae never mature out of larvae stage.
- AKA Visceral larvae migrans
- AKA Ocular larvae migrans if it gets into the eye → can cause blindness
Toxicara canis (Dog roundworm)
Tissue nematode (round worms)
lab tests / tx
Screamatodes III: Return of the flesh eaters
- Blood tests to detect antibodies to toxocara
- Eosinophilia
- Tx with Albendozole
Loa Loa (Filaria worm)
Tissue nematode (round worms)
source / signs and symptoms
Screamatodes III: Return of the flesh eaters
- Bite from deer fly → adult Loa Loa worm migrates throughout the subcutaneous tissues of humans
- Transient angioedema, localized subcutaneous swellings (AKA Calabar swellings; red and itchy)
- AKA “African Eye Worm“ (occasionally crosses into subconjunctival tissues of the eye where it can be easily observed!)
Loa Loa (Filaria worm)
Tissue nematode (round worms)
lab tests / tx
Screamatodes III: Return of the flesh eaters
- Diagnosed with a blood smear.
- Eosinophilia
- Tx with diethylcarbamazine and albendozole
Tinnea soleum and sagginatum
Cestodes (tape worms)
lab tests / tx
Cestode County Carnival
- O&P stool sample will show hooks on proglottid (segment) heads of T. soleum (pig intermediate!), no hooks on T. sagginatum (cow intermediate!).
- tx with Pa_r_aziquantal**
- Neurocysticercosis tx with addition of abendozle
Tinnea soleum and sagginatum
Cestodes (tape worms)
Hosts
Cestode County Carnival
Often found in immigrants or farmers.
- Intermediate hosts for T. soleum are pigs.
- intermediate hosts for T. sagginatum are cows.
Tinnea soleum and sagginatum
Cestodes (tape worms)
2 types of transmission
Cestode County Carnival
- Ingestion of cysts or larvae in undercooked meat → GI issues or malabsorption (Taeniasis)
- Ingestion of poop water contaminated with Tinnea eggs** → goes to **brain** (_Neuro_cysticercosis) or tissues (Cysticercosis**).
Tinnea soleum and sagginatum
Cestodes (tape worms)
signs and symptoms
Cestode County Carnival
- Taeniasis: Gi issues or malabsorption
- Cysticercosis: Lumps in tissue under skin
- Neurocysticercosis: Seizures, lesions (swiss cheese appearance!) in brain, eyes, and skin, hydrocephalus
Diphyllobothrium latum
Cestodes (tape worms)
source / signs and symptoms
Cestode County Carnival
Found in uncooked or undercooked fish.
Causes diarrhea (sm. intestine) & associated B12 (Cobalamin) deficiency → Megaloblastic anemia
Diphyllobothrium latum
Cestodes (tape worms)
lab tests / tx
Cestode County Carnival
- O&P stool sample will show proglottid segments.
* Largest tapeworm, up to 10 meters!!!
- tx with Pa_r_aziquantal** or **Niclosamide
Echinococcus granulosus
Cestodes (tape worms)
source / signs and symptoms
Cestode County Carnival
Dogs are the definitive host → Sheep are the intermediate host → Humans are incidental hosts.
- Transmission to humans via dog feces (in food or water)
- Cause hydated cysts (clear fluid inside the cysts, look like slow growing tumors)
- Cyst like mass in liver shows “Eggshell calcifications” on CT
Echinococcus granulosus
Cestodes (tape worms)
lab tests / tx
Cestode County Carnival
- “Eggshell calcifications” on CT of liver
- When cysts rupture they can cause an anaphylaxis reaction!
- When attempting removal, must inject with solution (ethanol or hypertonic saline) to kill the cysts before removal.
- Eosinophilia
Schistosoma mansoni, japonicum, haematobium
Trematodes (flukes / flat worms)
source / infection cycle
San Fran-schisto ocean park (Schistosomiasis)
- Free living aquatic organisms → gain entrance through the skin → enter blood stream → carried to liver → mature into adults in the liver! → humans poop and pee into water → snails become intermediate hosts → adult then migrate AGAINST** the **portal flow in the venus system to reach their destination.
- S. mansoni and S. japonicum like to reside in mesenteric veins.
- S. haematobium likes to reside in veins of bladder.
Schistosoma mansoni, japonicum, haematobium
Trematodes (flukes / flat worms)
signs and symptoms
San Fran-schisto ocean park (Schistosomiasis)
- Swimmers itch where larvae penetrate the skin.
S. mansoni and S. japonicum:
- Portal HTN → (chronically) GI distension and abdominal pain.
- Liver cirrhosis and jaundice.
S. haematobium:
- Hematuria in bladder and risk of bladder cancer.
Schistosoma mansoni, japonicum, haematobium
Trematodes (flukes / flat worms)
lab tests / tx
San Fran-schisto ocean park (Schistosomiasis)
Tx for all Trematodes (flukes): Pra_z_iquantal**
On stool O&P you will see:
- S. mansoni: large lateral spine on the side of the body of the egg
- S. japonicum: small spine (or absent) on eggs. Mostly round.
- S. haematobium: Large terminal spine
Clonirchis sinensis
Trematodes (flukes / flat worms)
source / signs and symptoms
San Fran-schisto ocean park
- “Chinese liver fluke”
- Snails are intermediate host → transfered to fish → Humans eat cysted larvae in uncooked fish.
Leads to:
- Biliary track fibrosis** and _cholangio_carcinoma** (bile duct cancer)
- Pigmented gallstones
Clonirchis sinensis
Trematodes (flukes / flat worms)
lab tests / tx
San Fran-schisto ocean park
Tx for all Trematodes (flukes): Pra_z_iquantal**
On stool O&P you will see:
- Operculated eggs (looks like little hats on eggs)
Parogonimus westermonti
Trematodes (flukes / flat worms)
source / signs and symptoms
San Fran-schisto ocean park
- “Lung fluke”
- Snails are intermediate host → transfered to crab** → Humans eat **cysted larvae in undercooked crab meat.
Leads to:
- Chronic cough w/ bloody sputum
Parogonimus westermonti
Trematodes (flukes / flat worms)
lab tests / tx
San Fran-schisto ocean park
Tx for all Trematodes (flukes): Pra_z_iquantal**
On stool O&P you will see:
- Operculated eggs (looks like little hats on eggs)
