Infections of GI tract Parasitic Infections: schoenwald (exam 3)

Question 1

List Ex’s of Parasitic Infections:

Answer 1

• Giardia
• Amoeba
• Helminths
• Cryptosporidia

Question 2

Giardia Lamblia is the MC cause of epidemic _____ borne diarrheal disease in US

Answer 2

water borne

Question 3

Giardia lamblia:

• Troph and ____ forms
• Most frequently identified _______ in the US

Answer 3

• Troph and cyst forms (can infect in these forms)

- Most frequently identified **protozoan in US, especially Rocky Mountain region

Question 4

Giardia lamblia:

• colonizes the ______ and jejunum
• disrupts the ______ function
• fecal to _____ transmission

Answer 4

• Colonizes *duodenum and jejunum
• Disrupts the epithelial fxn=malabsorption

-Fecal to oral transmission

Question 5

Giardia lamblia:

Sx?

Answer 5

• Sudden onset explosive diarrhea 1-3 weeks after exposure
• Abdominal cramping
• Flatulence
• Low grade fever
• Nausea/vomiting

Question 6

Giardia: Dx

-gold standard test?

Answer 6

• O and P= gold standard (ova and parasite (O&P) exam)
• ELISA-Stool Antigen testing (this one is used more now, BUT know the gold standard for boards)
• Stool PCR
• Duodenal biopsy

Question 7

Giardia:

tx?

Answer 7

metronidazole or tinidazole

Question 8

Giardia: prevention?

Answer 8

DONT drink the water!! lol

can cause significant weight loss

Question 9

Entamoeba histolytica:

trophs invade the intestinal _______

Answer 9

Trophs invade intestinal epithelium, can penetrate venules and lymphatics to gain access to liver

Question 10

Entamoeba histolytica:

-primary site?

Answer 10

Liver= primary site of extraintestinal disease but may disseminate into lung, pericardium, and brain

Question 11

Entamoeba histolytica:
clinical sx?
-prodrome Sx?

Characteristic fluid description?*

Answer 11

• Prodrome of Sx: diarrhea, abdominal cramping, nausea, vomiting, tenesmus
• Malaise, loss of appetite, weight loss, mental apathy
• Watery stool containing mucus and blood
• Tender liver enlargement-liver abscess
• Meningeal signs-brain abscess

“chocolate milk like” in appearance –> THINK Entamoeba abscess of the liver!! **KNOW

Question 12

Entamoeba histolytica:
Dx?
Tx?

Answer 12

• O and P (ova and parasite)
• Serology

Tx: metronidazole or tinidazole

-Prevent with good sewage and water treatment plants

(abscesses will need to be drained)**

-cousin to Entamoeba histolytica known as entamoeba coli–> IT IS NOT pathogenic!! -schoenwald

Question 13

Cryptosporidium:

-etiology?

Answer 13

Contaminated fruit, vegetables and water

Question 14

Cryptosporidium:

-important in which Pt population?

Answer 14

• Important in immunosuppressed/HIV

- In immune competent individuals, asymptomatic

Question 15

Cryptosporidium:

-sx?

Answer 15

Diarrhea, dehydration, lung or gallbladder involvement in immunosuppressed

Question 16

Cryptosporidium:

• dx?
• tx?

Answer 16

-Diagnosis- stool AFB stain, stool Antigen test, stool pcr

Acid fast bacillus stain for cryptosporidium= pinkish reddish

tx: nitazoxinide (Alinia)= ONLY FDA approved tx

Question 17

Cryptosporidiosis:

US outbreaks 2009-2017

Answer 17

• pools: 37%
• cattle: 15%
• Childcare: 13%

Question 18

Helminth infections:

-organism? (hint: 4 kinds of worms)

Answer 18

(helminths= are worms)
-Ascaris lumbricoides-intestinal roundworm

• Trichinella spirosis-trichinosis
• Enterobius vermicularis-pinworm
• Ancyclostoma and Necatur-hookworms

Question 19

Ascaris lumbricoides is the largest and most _____

Answer 19

common

Question 20

Ascaris lumbricoides:

-describe the worm and route of infection

Answer 20

• Adult worm inhabits small intestine and deposits eggs into intestinal lumen
• Eggs passed into feces
• Larvae from ingested eggs enter bloodstream, pass through alveoli, blocked at pulmonary capillaries, rupture into alveolar spaces
• Coughed and reingested

Question 21

Ascaris lumbricoides:

-Sx depend on ____

Answer 21

• worm load
• High worm load= cough, fever, wheezing , shortness of breath, oxygen desat
• -Eosinophilia

Question 22

Ascaris lumbricoides:
Dx?

Tx?

Answer 22

• O and P
• Eosins and larvae in sputum

tx: mebendazole or albendazole

Question 23

Trichinella spirosis:

• organism?
• etiology?

Answer 23

• Trichinosis

- Raw or undercooked meat esp pork

Question 24

Trichinella spirosis:

-infection causes?

Answer 24

• Muscle infection with parasite
• ->Paralysis of muscles
• ->Weakness, muscle pain

Question 25

Trichinella spirosis:

• lab findings?
• tx?

Answer 25

• Elevated CK, LDH, Eosinophils

- Tx: albendazole or mebendazole

Question 26

Enterobius vermicularis:

• parasite?
• Demographic and MC Sx?

Answer 26

• pinworm
• Sx usually in kids and worse at bedtime
• Anal pruritis

Question 27

Enterobius vermicularis:

• Dx based on ____
• tx?

Answer 27

**finding adult worm in anal area, scotch tape prep

-Tx: mebendazole, all in family should be treated

Question 28

Necatur and Ancyclostoma:

-parasite?

Answer 28

Hookworms

Question 29

Necatur and Ancyclostoma:

• can infect ____ systems
• Sx?

Answer 29

-pulmonary, dermal and GI systems

Sx: specific for area of infection

• Able to enter through skin
• **“hook” onto colon wall, can cause anemia

Question 30

Hookworm lifecycle

Answer 30

humans are usually the carrier, and human fecal material that gets deposited in soil–> larvae hatch and people that come into contact with that soil or dogs can get the hookworm infection

Question 31

Cutaneous larva migrans=

Answer 31

=dermal hookworm infections

(typically of the feet)

• Pt may have walked barefoot on the beach and the larvae of the worm hooked onto their foot
• Tx: DO NOT REMOVE THE WORM–> this spreads it more as the eggs hatch

Question 32

Necatur and Ancyclostoma (“hookworm”):

tx?

Answer 32

Tx: DO NOT REMOVE THE WORM–> this spreads it more as the eggs hatch

**Mebendazole or albendazole