Draft Mid 13. Helminths 1

Front 1

What are the 5 kinds of luminal nematodes and their salient points?

Back 1

Ascaris: largest round worm

Hookworm: Causes Fe deficiency anemia

Strongyloides: only worm that can multiply within host; dangerous in immunocompromised folks

Pin Worm (Enterobius): causes an itchy butt

Whip Worm (Trichuris): causes rectal prolapse; can cause Fe anemia

Front 2

What are 3 basic points about nematodes (round worms)?

Back 2

1. Eukaryotes. C. elegans is most common--lives in soil.

2. Most are non-parasitic

3. Almost 4 billion people harbor at least one species of parasitic nematode. Many have >1.

Front 3

What is Night soil?

Back 3

-Feces-fertilized soil
-completes the nematode parasite cycle

Front 4

What is Enterobius vermicularis?
How prevalent is it in the US?
Discuss how we obtain it and its phases?

Back 4

-Pinworm
-most common human helminth in the U.S
-we ingest the eggs
-no soil, lung or GI invasion phases

Front 5

What type of worm is this?

Back 5

Enterobius vermicularis
Pinworm

Front 6

Discuss the Life cycle of Enterobius vermicularis and where it infects

Back 6

Front 7

What worms causes this?

Back 7

Enterobius vermicularis- pinworms

Front 8

Back 8

-unembryonated (classic appearance) and embryonated forms.
-flat on one side, round on the other.
-can see larva inside

Front 9

What is the diagnosis test for Enterobius vermicularis:

What are the two treatment options

Back 9

-scotch tape test

albendazole*
mebendazole*
single dose + repeat after 2 weeks
* inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin)
They are both effective and convenient

Front 10

Discuss prevent of enterobius vermincularis and why it is difficult in certain populations

Back 10

Front 11

What is trichuris trichiura

Back 11

-Whipworm
-3rd most common human helminth globally
-soil phase and local GI invasion but no lung phase
-We ingest the eggs
-It has a simple slow life cycle

Front 12

What worm is this?

Back 12

-adult F on left

Front 13

Describe the life cycle of Trichuris trichiura.
What are the symptoms and pathology

Back 13

-Rectal prolapse and bleeding
-can cause Fe anemia
-abdominal pain, nausea
-mucus/blood in stool (dysentery)
-chronic infection
-can be asymptomatic

Front 14

What is happening here and what worm causes it?

Back 14

Rectal prolapse in Trichuris trichiura.

Front 15

What is the diagnosis technique of Trichuris trichiura?

Back 15

-µscopic exam of feces for eggs
-ova and parasite test (O&P)
-made by identifying eggs in fecal specimens. The eggs look like footballs with bumps on each end. (TEA-TRAY)

Front 16

Back 16

TEA-TRAY

Front 17

What is the treatment of Trichuris trichiura?

Back 17

albendazole (3 days)*
mebendazole (3 days)*

* inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin)

Front 18

What is Ascaris lumbricoides?

Back 18

-giant intestinal roundworm
-most common human helminth globally
-soil phase, GI invasion & lung phase
*can present like pneumonia

Front 19

What worm is this?

Back 19

Ascaris lumbricoides

Front 20

What is the life cycle of ascaris lumbricoides

Back 20

Larvae mature to adults and produce eggs which pass out in feces--> ascaris egg is ingested-->larvae emerge in small intestine-->larvae penetrate intestine wall and travel to lung-->in lung, larvae grow and are coughed up and swallowed-->larvae reach intestine for second time-->Larvae mature to adults and produce eggs which pass out in feces (CYCLE COMPLETED)

Front 21

How does infection present in ascaris lumbricoides?

Back 21

*loeffler's is the lung syndrome

Severe infections involve adult worm invasion into the bile ducts, gall bladder, appendix, and liver

Front 22

What does this child have

Back 22

-child with heavy ascaris lumbricoides infection
-PEM, or full of worms

child may suffer from malnutrition because the worms compete for the same food and sometimes a mass of worms can actually block the intestine

Front 23

What are 5 common sites of migration in ascaris lumbricoides?

Back 23

bile ducts, gall bladder, liver, appendix

Front 24

What is this?

Back 24

-eggs with larvae of ascaris lumbricoides.
Classic appearance
Rough on the outside

Front 25

What is this?

Back 25

See it visibly, can get pretty long

Front 26

What is the treatment of Ascaris lubricoides:

Back 26

albendazole (1 dose)* -best method
mebendazole (3 days)*

* inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin)

Front 27

What is this?

Back 27

See it visibly, can get pretty long

Front 28

Most common types of hookworms:
How prevalent are they?
What phases do they come in?

Back 28

1) Necator americanus
2) Ancylostoma duodenale

-2nd most common human helminth globally

-soil phase, GI invasion & lung phase

Front 29

Significance of the pit privy?

Back 29

-prevents fecal/oral spread because hookworms can crawl only so high out of a pit.
-instrumental in stopping spread of them.

Front 30

What type of worm is this?

Back 30

adult Ancylostoma duodenale

Front 31

What type of worm is this?

Back 31

adult Necator americanus

Front 32

Back 32

Front 33

What is the life cycle of hookworms

Back 33

In soil eggs hatch releasing larvae which develop into filariform larvae-->filariform larvae penetrate between toes of barefoot human-->filariform larvae travel directly to lung-->in lung larvae grow and are coughed up and swallowed-->larvae reach small intestine for first time-->larvae mature into adults which pass out in feces (CYCLE COMPLETE)

Front 34

What type of worm is this?

Back 34

adult hookworm seen on endoscopy.

Front 35

Clinical disease presentations from hookworms:

Back 35

1) Fe-deficiency anemia
2) FTS syndrome
3) Diarrhea
4) Abdominal pain, weight loss

Front 36

How do you diagnose hookworms

Back 36

Microscopy of fresh fecal sample
-thin shell
-eggs are in feces
-sometimes see larva inside

Front 37

How do you treat of hookworms?

Back 37

albendazole (1 dose)*
mebendazole (3 days)*
pyrantel pamoate (3 days)

* inhibits polymerization of microtubules which results in depetion of glycogen stores (has no effect on human tubulin)

Front 38

What are the phases of Strongyloides stercoralis?

Back 38

-soil phase, GI invasion, lung phase and free-living cycle

-Larvae in soil penetrate skin

Front 39

What is this?

Back 39

-free living female Strongyloides stercoralis

Front 40

Who in the U.S. might have Strongyloides stercoralis?
worldwide?

Back 40

-Southeastern US and the Appalachia region (esp. eastern Tennessee, Kentucky, & West Virginia) & Puerto Rico
-immigrants, refugees, and military veterans

Front 41

What is the life cycle of Strongyloides stercoralis:

Back 41

*Larvae pass out from stool, NOT EGGS*
*free living types*
*can autoinfect you-->shock, death*

Autoinfection: the filariform larvae penetrate the intestine directly, without leaving, and go to the lung to continue the cycle
Direct cycle: The filariform larvae pass out in the feces, survive in the soil, penetrate the next passerby, and migrate to the lungs. This complete cycle is almost exactly the same as that of Necator americanus
Indirect cycle: This is a sexual cycle where the filariform larvae are passed out in the stool and while in the soil develop into male and female adults. They mate in the soil and produce fertilized eggs. The filariform larvae then hatch and reinfect a human, moving the the lung

Front 42

What are the clinical manifestations of Strongyloides stercoralis:

Back 42

-asymptomatic
-skin rash/urticaria at entry site (“ground itch”)
-pulmonary symptoms (Loeffler’s Syndrome”)
-abdominal pain, N&V, diarrhea, dysentery
-malabsorption & loss of weight
-anemia (ingest blood from intestinal walls)
*2˚ bacterial sepsis (worms release bacteria/ translocation)
**hyperinfection syndrome (HIV/immunocompromised) with eosinophilia** SHOCK
-death

Front 43

How do you diagnose of Strongyloides stercoralis

Back 43

Microscopic
String Test
Serology
-No eggs in the stool
-serology is best (but presence of Abs in not always clear)

Front 44

What is the treatment of Strongyloides stercoralis

Back 44

ivermectin (2 days)*
albendazole (7 days)

* Binds to glutamate-gated Cl- ion channels in invertebrate muscle and nerve cells causing paralysis and death of the parasite; also acts as an agonist of GABA, disrupting neurosynaptic transmission.

Front 45

What is cutaneous larva migrans

Back 45

-Ancylostoma braziliense & Ancylostoma caninum
-hookworms from young dogs and cats
-fail to penetrate skin
-“creeping eruption”= “ground itch”
-warm climates
-not dangerous, easily treatable

Front 46

What is the treatment of Cutaneous larva migrans?

Back 46

albendazole (3 days)
ivermectin (1-2 days)*

* Binds to glutamate-gated Cl- ion channels in invertebrate muscle and nerve cells causing paralysis and death of the parasite; also acts as an agonist of GABA, disrupting neurosynaptic transmission.

Front 47

Which worms do you EAT?

Which ones get into you feet from the SAND?

Back 47

Enterobius, Ascaris, Trichuris

Strongyloides, Ancylostoma, Necator