parasitic infestations: roundworms/nematodes Flashcards Preview

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Flashcards in parasitic infestations: roundworms/nematodes Deck (28):
1

Enterobius vermicularis

adult size?


egg size?

human pinworm ("seatworm")

10 mm, 0,4 mm across, backside tapers to a point, male is about half female size

fully embryonated, infective-stage ova are elongated-ovoid, flattened on one side, and average 55 by 25 nm (small!)

2

enterobius vermicularis adult pinworm lives freely in the ??

after copulation, adult female contains about 10^4 ??
she migrates thru ?? onto ?? where her uterus ?? and ??

transverse and desc. colon and rectum

fertilized but nonembryonated eggs
the anus onto perianal skin, prolapses and she releases her eggs and dies
*larvae have been know to migrate back up anus*

3

after release, the Entero vermi eggs embryonate and take how long to become infective ??
eggs are resistant to ?? and easily spread how ??

6 hrs

desiccation, easily spread under clothing, bed sheets ("fluffing"), and fecal/oral route

4

release of Entero vermi worm Ag often causes ??
not good to ?? bc ??

Type 1 hypersensitivity reaction, pruritis
scratch, eggs go under fingernails

5

when Entero vermi eggs ingested the hatch upon reaching ?? where they also develop into an adult and migrate to the ??

the small intestine

large intestine

6

pinworms(Entero vermi) live for

90 days

7

pinworms typ. infect who ??

day care, school children (4-15)
*most common intestinal nematode*

8

mode of Enterobius vermicularis transmission ??

anus-mouth via fingers ("thumb-suckers")
airborne ova may be ingested/inhaled
parents of infected kiddos from close contact, changing clothes/bed sheets, hygiene

9

majority of enterobius vermicularis (pinworm) inf. are

asymptomatic

10

pinworm inf. symptoms


assoc. with ??

pruritis ani and vulvae (itchy butt/vagina), vaginal discharge (losing worms)

appendicitis, PID, granuloma formation

11

other complications of pinworms

behavior changes, loss of sleep (itchy butt), grinding teeth

12

ddx pinworms

ADHD, behavioral distrubances, H. nana infection

13

dx pinworms: 1st consider ??
good simple test ??

pt age, hx, clinical observations
scotch tape test; may reveal ova in 50% of cases, 3 tests: 90%

14

pinworm tx

Pyrantel pamoate: deworming for hookworms/roundworms, depolarizing NM blocker, causes worm to lose grip on intestinal wall and be pooped out

Mebendazole: all worms; inhib. synthesis of microtubles in parasitic worms

repeat both 2-3 wks later to kill hatched eggs (not egg-cidal)

15

pinworm (entero vermi)
high probability of infection/reinfection due to ??

persistence of eggs and ease of transmission
so *poor hygiene is NOT necessarily a factor*

16

Trichuris trichiura

morphology

diecious nematode (roundworm)
human whipworm

thin front, thick back, barrel-shaped with bipolar prominences ("plugs")

17

Trich adults live in ?? with ?? embedded w.in the epithelium and ?? protruding in lumen, so considered ??

transverse and desc. colon, the ant. portion
the posterior, minimally invasive

18

Trich female produces ?? ova /day which are pooped out and must ?? for how long ?? to become infections
environmental requirements ??

3-5 x 10^3
undergo embryonation for 18-25 days
high humidity and warm temps

19

become infected with Trich via ??
eggs hatch in ??? where it ??
moves on to ??
whole cycle time length ??

eating eggs
small intestine, attaches, matures
colon where it mates and the cycle begins again
totaling 90 days

20

Trich worms can live for ??

1-5 yrs

21

Trich is found where ??



who most affected?

poor hygiene/latrine facilities in warm/moist climates (for embryonation)
SE US and developing countries
800 mil inf. ww,
kiddos>adults

22

Trich spread from ??

"night soil": feces in fertilizer, imported

23

Trichuriasis presentation: light vs heavy infection



light: asymptomatic

heavy: dysentery, "trichuris dysentery syndrome"
abd. pain, distention, bloody or mucoid diarrhea
-don't rule out co-infection

24

other complications of heavy Trich infection

appendicitis
rectal prolapse

25

Trichuriasis may spread ??
if heavy worm burden in kiddos this may occur ??

systemically
blood loss-->anemia (confounding: previously malnourished)

26

Trich lab dx: demonstrate worms via

1. proctoscopic exam
2. find ova (bipolar plugs) in poop
-can also find Charcot-Leyden crystals
-eosinphilia in heavily infected individuals

27

Trich tx

Mebendazole for sympt. cases
90% cure rate! good px

28

Trich ppx

sanitary disposal of poop
wash hands and raw fruits/veggies
don't use "night soil"

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