Helminths I- Luminal Nematodes

Front 1

Quick salient/disgusting points about the luminal nematodes: 5 kinds

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

Soil transmitted helminths (geohelminths):
-prevalence of 3 major species?
-locations around the globe?

Back 2

Ascaris lumbricoides 1.2 billion
Trichuris trichiura 800 million
Hookworms 740 million

-Mostly in sub-Saharan Africa, the Americas, China and east Asia.

Front 3

3 basic points about nematodes (round worms):

Back 3

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 4

Night soil:

Back 4

-Feces-fertilized soil
-completes the nematode parasite cycle

Front 5

Enterobius vermicularis:

Back 5

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

Front 6

Back 6

Enterobius vermicularis
Pinworm

Front 7

Life cycle of Enterobius vermicularis:

Back 7

Front 8

Back 8

Enterobius vermicularis- pinworms

Front 9

Back 9

-unembryonated and embryonated forms.
-flat on one side, round on the other.

Front 10

Diagnosis of Enterobius vermicularis:

Treatment: 2

Back 10

-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)

Front 11

Prevention and Control of Enterobius vermicularis:

Back 11

Front 12

Trichuris trichiura:

Back 12

-Whipworm
-3rd most common human helminth globally
-soil phase and local GI invasion but no lung phase
-We ingest the eggs

Front 13

Back 13

-adult F on left

Front 14

Life cycle of Trichuris trichiura:
symptoms/pathology?? 5

Back 14

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

Front 15

Back 15

Rectal prolapse in Trichuris trichiura.

Front 16

Diagnosis of Trichuris trichiura:

Back 16

-µscopic exam of feces for eggs
-ova and parasite test (O&P)

Front 17

Back 17

Front 18

Treatment of Trichuris trichiura:

Back 18

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

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

Front 19

Ascaris lumbricoides:

Back 19

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

Front 20

Back 20

Front 21

Life cycle of ascaris lumbricoides:

Back 21

Front 22

How does infection present in ascaris lumbricoides?

Back 22

*loeffler's is the lung syndrome

Front 23

Back 23

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

Front 24

Common sites of migration in ascaris lumbricoides: 5

Back 24

Front 25

Back 25

-eggs with larvae of ascaris lumbricoides.

Front 26

Back 26

Front 27

Treatment of Ascaris lubricoides:

Back 27

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 28

Back 28

Front 29

Most common types of hookworms: 2
prevalence:
Phases: 3

Back 29

1) Necator americanus
2) Ancylostoma duodenale

-2nd most common human helminth globally

-soil phase, GI invasion & lung phase

Front 30

Significance of the pit privy?

Back 30

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

Front 31

Back 31

adult Ancylostoma duodenale

Front 32

Back 32

adult Necator americanus

Front 33

Back 33

Front 34

Life cycle of hookworms:

Back 34

Front 35

Back 35

adult hookworm seen on endoscopy.

Front 36

Clinical disease presentations from hookworms:

Back 36

1) Fe-deficiency anemia
2) FTS syndrome

Front 37

Diagnosing hookworms:

Back 37

-thin shell
-eggs are in feces

Front 38

Treatment of hookworms:

Back 38

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 39

Strongyloides stercoralis: phases

Back 39

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

-Larvae in soil penetrate skin

Front 40

Back 40

-free living female Strongyloides stercoralis

Front 41

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

Back 41

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

Front 42

Life cycle of Strongyloides stercoralis:

Back 42

*Larvae pass out from stool*
*free living types*
*can autoinfect you-->shock, death*

Front 43

Clinical manifestations of Strongyloides stercoralis:
run the gamut

Back 43

-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**
-death

Front 44

Diagnosis of Strongyloides stercoralis: 3

Back 44

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

Front 45

Treatment of Strongyloides stercoralis: 3

Back 45

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 46

Cutaneous larva migrans: 2 kinds

Back 46

-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 47

Treatment of Cutaneous larva migrans:

Back 47

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 48

Which worms do you EAT?

Which ones get into you feet from the SAND?

Back 48

Enterobius, Ascaris, Trichuris

Strongyloides, Ancylostoma, Necator