Nematodes - Aphasmids

Question 1

CHARACTERISTICS

Caudal papillae is (present, absent)

Excretory system (with, without) lateral canals

Phasmids (present, absent)

Esophagus is cylindrical-____ or ___

______ eggs with polar plugs or hatches in the uterus

• 1st larval stage= (with, without) stylet

Answer 1

• Caudal papillae is reduced or absent
• Excretory system without lateral canals
• Phasmids absent
• Esophagus is cylindrical-stichosome or trophosome
• Unsegment eggs with polar plugs or hatches in the uterus
• 1st larval stage=with stylet

Question 2

Threadworm

Answer 2

TRICHINELLA SPIRALIS

Question 3

T. spiralis found in

Answer 3

worldwide in many carnivorous and

omnivorous animals

Question 4

T. pseudospiralis found in

Answer 4

mammals and birds worldwide

Question 5

T. nativa found in

Answer 5

Arctic bears

Question 6

T. nelsoni found in

Answer 6

African predators and scavengers

Question 7

T. britovi found in

Answer 7

carnivores of Europe and western Asia

Question 8

T. papuae found in

Answer 8

wild and domestic pigs, Papua New Guinea and

Thailand

Question 9

Trichinella zimbabwensis

Answer 9

crocodiles

Question 10

infective stage of t. spiralis

Answer 10

encysted larvae(except for T.
pseudospiralis and T. papuae, which do not encyst)

Question 11

800-120um at birth
• 200-100um in muscle fiber
• Has a burrowing tip (spear like)
• Mature larva has digestive tract
• Not fully developed reproductive organ

Answer 11

larva of t. spiralis

Question 12

• Found in small intestine
• Smallest nematode parasite of man
• Adult male:
o With conical papillae used in holding female during
copulation
• Adult female:
o With club-shaped utero;larviparous/viviparous
• Small worm with a slender anterior
• Protrusible stylet
• Cephalic papillae
• Stichosome present(with lined stichocytes)

Answer 12

adult of t. spiralis

Question 13

Requires 2 host to complete the life cycle

Answer 13

t. spiralis

Question 14

Spread by black and brown rats

Answer 14

t. spiralis

Question 15

dead end host of t. spiralis

Answer 15

man

Question 16

MOT of t. spiralis

Answer 16

ingestion of improperly cooked meat

Question 17

what kills t. spiralis

Answer 17

Freezing at -15°C for 20 days

Question 18

PATHOGENESIS AND CLINICAL PRESENTATION of t. spiralis

Answer 18

Asymptomati
Intestinal invasion
Larval migration into muscle tissues (one week after
infection)

(LIA)

Question 19

PATHOGENESIS AND CLINICAL PRESENTATION of t. spiralis - Intestinal invasion

Answer 19

(diarrhea, abdominal pain, vomiting)

Question 20

PATHOGENESIS AND CLINICAL PRESENTATION of t. spiralis - • Larval migration into muscle tissues (one week after
infection)

Answer 20

o periorbital and facial edema, conjunctivitis, fever,
myalgias, splinter hemorrhages, rashes, and
peripheral eosinophilia.
o Occasional life-threatening manifestations include
myocarditis, central nervous system involvement, and
pneumonitis.
o Larval encystment in the muscles causes myalgia and
weakness, followed by subsidence of symptoms

Question 21

(t. spiralis)

__ larvae/g body muscle=death

Answer 21

5

Question 22

(t. spiralis)

___ causes local edema

Answer 22

larva

Question 23

(t. spiralis)

__ causes muscle pain difficulty in swallowing
heart failure leading to death

Answer 23

Encysted larva

Question 24

(t. spiralis)

look for encysted larva thru

Answer 24

Muscle biopsy

Question 25

(t. spiralis) Immunodiagnostic tests:

Answer 25

Bentonite flocculation test; | Bachman’s test (intradermal skin test)

Question 26

(t. spiralis) Xerodiagnosis using

Answer 26

test albino mice (Beck’s Test)

Question 27

(t. spiralis) Bachman intradermal test

Answer 27

o Ag: 1:5000- 1:10000 dilution | o (+) within 15-20 minutes

Question 28

(t. spiralis) Serologic Test

Answer 28

o Bentonite flocculation test o CFT o IHT (BIC)

Question 29

(t. spiralis) Drugs of choice

Answer 29

o Albendazole – 400 mg twice a day by mouth for 8 to 14 days o Mebendazole – 200 to 400 mg three times a day by mouth for 3 days, then 400 to 500 mg three times a day by mouth for 10 days

Question 30

Most common in parts of Europe and the United States

Answer 30

t. spiralis

Question 31

• Cooking meat to a uniform temperature of 70 degrees Celsius or higher for at least a few minutes to kill encysted larvae. • Freezing of pork meat to a temperature of -30 degrees Celsius for one week reportedly kills the encysted larvae (may not be effective forwild game meat). • Other cooking methods such as microwaving, smoking, or saltingmeat often fail to kill the encysted larvae and thus the risk of getting trichinosis from meat treated by these methods is increased. prev. and control for

Answer 31

t. spiralis