Helminthic GI (lec 8)

Question 1

Nematode (roundworm) morphology?

Answer 1

elongated, tapering cylinder,
multiple layers of cuticle,
separate sexes

Question 2

Nematode Life Cycle?

Answer 2

Eggs in environment
Larvae enviro to host
Adult in host

Question 3

E. vermicularis (pinworms) epidemiology?

Answer 3

Most common helm dz in US,
P-to-P or environment
(U) kids

Question 4

E. vermicularis infection causes?

sxs?

Answer 4

enterobiasis

(U) asymp
anal itching
(P) 2º bacterial infection

Question 5

E. vermicularis Life Cycle?

Answer 5

1) Eggs deposited on perianal (infectious w/i 4 hrs)
2) Eggs ingested and hatch in SI
3) Mature/colonize ~ 2mo
4) GRAVID female deposits eggs on anus at night

Eggs in environment survive 2-3 wks

Question 6

E. vermicularis diagnostics?

Answer 6

anal eggs

Question 7

E. vermicularis tx?

Answer 7

DOC: Mebendazole or Albendazole

*treat whole family

Question 8

Ascaris lumbricoides morph?

Answer 8

Largest intestinal worm in humans

Question 9

A. lumbricoides epidemiology?

Answer 9

Soil transmission,

(C) warm climates

Question 10

A. lumbricoides Life Cycle?

Answer 10

1) Eggs ingested -> larva released into duo
2) Larva penetrate mucosa -> blood into lungs
3) Alveoli -> trachea -> orophary
4) Swallowed beck to duo -> mature

Adults live 2 yrs

Question 11

A. lumbricoides causes?

sxs?

Answer 11

Ascariasis

Asymp - blockage
depends on # of worms
(P) Pulmonary-Leoffler’s synd

Question 12

A. lumbricoides diagnostics?

Tx?

Answer 12

Eggs in stool

DOC: Mebendazole or Albendazole

Question 13

Trichuris trichiura (whipworm) morph?

Answer 13

small, whiptail

egg capsules

Question 14

T. trichiura Life Cycle?

Answer 14

1) Embryonated eggs ingested
2) Larvae released in duo
3) Mature in colon
4) Released eggs can mature in soil

Question 15

T. trichiura epidemiology?

Answer 15

Soil transmission

(U) kids

Question 16

T. trichiura causes?

sxs/

Answer 16

trichuriasis

dependent on worm burden
aysmp to painful watery stool w/ mucus/blood
(P) rectal prolapse

Question 17

T. trichiura diagnostics?

Tx?

Answer 17

Eggs in stool

DOC: Mebendazole or Albendazole

Question 18

Necator americanus/Ancylostoma duodenale

(hookworms) Life Cycle?

Answer 18

1) Infective eggs in soil
2) Larvae penetrate skin -> blood into lungs
3) Alveoli -> trachea -> orophary
4) Swallowed beck to duo -> mature
5) Feeds on blood in mucosa

Question 19

N. americanus

A. duodenale epidemiology?

Answer 19

Human feces in soil

Question 20

N. americanus

A. duodenale sxs?

Answer 20

Depends on worm burden and host’s nutrition

Blood-filled, pruritic lesions at penetration site,
Constant blood loss from GI

Question 21

N. americanus
A. duodenale diagnostics?

Tx?

Answer 21

Eggs in stool

DOC: Mebendazole

Question 22

Strongyloides stercoralis (threadworm)
Life Cycle?

Answer 22

Two Cycles:
1) Same as hookworm -> larvae into feces

2) Multiply in soil

Question 23

S. stercoralis epidemiology?

Answer 23

Human feces in soil

(U) tropical

Question 24

S. stercoralis causes?

sxs?

Answer 24

Dep on worm burden

Visible trail under skin,
Painful D or constipation,
Life-threatening if defective cell-mediated immunity,
Can auto-reinfect for yrs

Question 25

S. stercoralis diagnostics? Tx?

Answer 25

Larvae in stool or sputum DOC: Thiabendazole

Question 26

Trematodes (flukes) morph?

Answer 26

flat, leaf-like w/ suckers

Question 27

Clonorchis sinensis (chinese liver fluke) Life Cycle?

Answer 27

1) Ingest encysted larvae 2) Excystation in duo 3) Mature in bile ducts 4) Eggs -> poop

Question 28

C. sinensis epidemiology?

Answer 28

Poorly cooked fish | (C) far east

Question 29

C. sinensis causes? sxs?

Answer 29

Clonorchoriasis (U) asymp

Question 30

C. sinensis diagnostics? tx?

Answer 30

eggs in stool DOC: Praziquentel

Question 31

Taenia (tapeworms) morph? Hosts?

Answer 31

meters long scolex (suckers/hooks) Humans

Question 32

T. solium (pork) T. saginata (beef) Life Cycle?

Answer 32

1) Eggs ingested by cows/pigs 2) Hatch in duo -> penetrate wall 3) Cysticerci grow in mm Humans eat meat: 1) Cysticerci matures in jejun 2) Eggs (proglottids) -> poop

Question 33

T. solium (pork) T. saginata (beef) cause? sxs?

Answer 33

taeniasis t. solium also causes cysticercosis (U) asymp and one worm cysticercosis (P) lead to blindness, seizures

Question 34

T. solium (pork) T. saginata (beef) diagnostics? Tx?

Answer 34

Eggs/proglottis in stool CT Histo DOC: Praziquantel

Question 35

Diphyllobothrium latum (fish tapeworm) Life Cycle?

Answer 35

1) Eggs hatch in fresh water * series of host passages until 2) Larvae ingested by fish Humans/mammals eat fish: 1) Ingest larvae -> duo 2) Adults in jeju 3) Eggs pooped

Question 36

D. latum causes? sxs?

Answer 36

diphyllobothriasis (U) asymp competes for B12

Question 37

D. latum diagnostics? Tx?

Answer 37

Eggs in stool Anemia + hx of raw fish DOC: Praziquantel