VI-GI Nematodes

Question 1

nematodes characteristics

Answer 1

aka roundworms
1. single body unit non segmented
2. separate sexes
3. complete digestive systems aka mouth and anus

Question 2

cestodes characteristics

Answer 2

1. segmented bodies
2. hermaphroditic- ovaries and testies
3. absorb nutrients thru segments

aka tapeworms

Question 3

trematodes characteristics

Answer 3

aka flukes
1. non segmented leaf shape
2. hermaphroditic
3. primitive gut

Question 4

high risk for nematodes

Answer 4

-areas with poor sanitation in developing tropic countries
-children develop symptomatic
-SEC region in U.S

Question 5

nematode life cycle

Answer 5

egg > multiple larval > adult
-worms not replicate in humans but do have sex if male and female ingested
-need 2+ to shed eggs

number of worms depends on number of eggs ingested

Question 6

innate immune vs. nematodes

Answer 6

EOSINOPHILS

Question 7

enterobius vermicularis

Answer 7

aka pinworm
-most common helminthic infection in US
-round with one flat side on histology

Question 8

geohelminths

Answer 8

acquired thru contact with soil infected with larvae or eggs from inadequate disposal human waste, sewage water
-SEC has warm moist soil

Question 9

pinworm transmission

Answer 9

fecal oral- ingestion of eggs
reinfection common within families
-animal pinworms not the same

Question 10

pinworm symptoms

Answer 10

1. perianal itching, restless kids
2. appendicitis in adults

Question 11

pinworm treatment

Answer 11

-anti helminthic compounds, single dose to all household members
-can get over the counter

Question 12

trichuris trichiura appearance

Answer 12

aka whipworm (geo)
eggs look like lemons with plugs, adults look like whips

Question 13

whipworm transmission

Answer 13

tropics, SEC

-fecal oral from soil

Question 14

whipworm symptoms

Answer 14

-90% asymptomatic
-if show symptoms have heavy worm burden (200+), bloody mucus diarrhea, rectal prolaspe in children

Question 15

ascaris lumbricoides life cycle

Answer 15

causes ascariasis
-larval form burrow out of intestine to travel thru lungs and liver, re-enter small intestine to mature

show eosinophils since leaving intestines

Question 16

ascariasis symptoms

Answer 16

1. most asymp or range from abdom discomfort to death
2. intestinal: loss appetite, vomit, diarrhea, indigestion, may obstruct and cause nutritional def
3. pulmonary: mild cough, pneumonitis, allergic resp, asmatic attack

Question 17

ascariasis histologoy

Answer 17

bumpy eggs

Question 18

hookworm types

Answer 18

1. necator americanus
2. ancylostoma duodenale

Question 19

hookworm transmission

Answer 19

infectious larvae can burrow into intact skin from soil
-migrate up thru pharynx then swallowed to enter GI

esp children and preg women, associated with caribbean

Question 20

hookworm symptoms

Answer 20

1. ground itch
2. lung inflammation/pneumonia, eosinophilia
3. iron deficiency anemia from blood loss to worm feeding > exertional dyspnea, koilonychias, pale sclera

Question 21

strongyloides stercoralis life cycle

Answer 21

causes strongyloidiasis
-facultative aka can survive soil by itself, not need human
-larvae shed in feces of worms, eggs hatch in the intestine
-same mechanism as hookworm penetrating skin

Question 22

strongyloidiasis symptoms

Answer 22

1. low worm burden little symps or non specific
2. heavy burden - pulmonary inflamm and eosinophilia, hyperinfection from immune defense

Question 23

hyperinfection of strongyloidiasis

Answer 23

-worsening intestinal diarrhea and pulmonary symps
-disseminate so will migrate around, esp if immunosuppressed

Question 24

strongyloidasis diagnosis

Answer 24

detect larvae not eggs in stool

Question 25

treating nematodes

Answer 25

MOA’s
-inhibit mitosis in parastie, benzimidazole
-muscle paralysis of parasite- ivermectin (strong), pyrantel pamoate (pin)

single dose