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Flashcards in non-diarrheal invasive infestations Deck (58)
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1
Q

Ascaris lumbricoides

size

A

giant intestinal roundworm, “the wanderer”

adult female: 30 cm long, 5mm diameter
male: shorter, narrower, curved posterior with pair of copulatory spicules -yikes!

2
Q

Ascaris adults live in the ?? where they do not ?? but rather ??

A

small intestine

don’t hatch, but constantly move agains peristalsis

3
Q

Ascaris female produces how many eggs/day

eggs are ??? until they are deposited in soil with poop

embryonization can take place in ?? or longer if unfav. conditions

A

200,000 eggs/day

fertilized, not embryonated

2-4 wks

4
Q

when ingested, Ascaris larvae hatch in the ?? penetrate the ??and are carried via blood to ??

A

small intestine

lamina propria, carried to the liver, heart, then lungs

5
Q

in the lungs, Ascaris larvae lodge in the ?? and break out into the ??

from there the larvae actively migrate ???

A

alveolar capillaries
alveolar spaces

up the bronchi into the trachea, across the epiglottis
are SWALLOWED, reaching the lumen of the small intestine

6
Q

Ascaris lumbricoides larvae do what in the small intestine

A

grow and reach sexual maturity

cycle then begins again

7
Q

whole Ascaris cycle takes ??

how long to the worms live ??

A

2-3 mos

1-2 yrs

8
Q

Ascaris occurs where ??

host/reservoir?

A

S and SE US (need warm embryonation in soil)
humans are sole host/reservoir, 1-4 mill affected

Africa, Latin America, East Asia

9
Q

light Ascaris infections are

A

asymptomatic (typ. of parasites: host-parasite homeostasis)

10
Q

most intense reactions with Ascaris are caused by ??

what type of reaction occurs ??

A

migrating larvae, esp. if high numbers

Type 1 hypersensitivity rxn: cough, wheezing, urticaria, fever

11
Q

other complications of Ascaris larvae migration

A

hepatic damage
lung damage, vermis pneumonitis
other organs

12
Q

if moderately infected with Ascaris adult worms…

A

rarely symptomatic

vague abd pain, acute colicky pain (heavier infections)

13
Q

Ascaris aka “the wanderer” may pass spontaneously via

A

vomiting, thru nares when adult worms wander up there

14
Q

young kids with large Ascaris burden may ??

A

be malnourished or have nutr. deficiencies, stunted growth

15
Q

Ascaris adult worm infection complications

A

bolus obstruction
perforation of intestine
blockage of bile duct
-others related to aberrant adult migration

16
Q

this may irritate Ascaris adult worm and cause migration

A

tx for other nematode infections

17
Q

dx Ascaris

A

migrating larvae, vermis pneumonitis
hx, CXR
eosinophilia, Charcot-Leyden crystals NO anemia
worms in stool, other sites
ova in stool (easily found due to so many produced)

18
Q

Ascaris tx

A

mebendazole
pyrantel pamoate
good ppx

19
Q

how to prevent Ascaris

A

sanitary disposal of feces
educating at risk pop
washing raw fruit/veggies in clean water

20
Q

this 2 hookworms are very similar

but differ in ??

A

Necator americanus
Strongyloides stercoralis

different geography

21
Q

Necator americanus

crazy estimate !!

A

New World hookworm
-tropical and subtropical regions of Africa, Asia, Central and South America
-US: S/SE (2-15% prevalence)
estimated 1/6th of world infected!

22
Q

Ancylostoma duodenal

A

Old World hookworm

distribution overlaps Necator americanus

23
Q

N. americanus morphology

A

female adults: 1 cm, males a bit shorter
buccal cavity has 2 cutting plates

ova: thin-shelled, early cleavage stage found in feces
larvae: Rhabditiform (non-inf) and Filariform (infective)

24
Q

N. americanus adults live in ?? where the feed on ??

A

the small intestine, feed on the intestinal villi by their cutting plates (Necator) or teeth (Ancylostoma)

25
Q

N. american eggs are embryonated ?? after pooped out and deposited in soil
the ?? will hatch w.in 48 hrs of deposition and will grow/dev. in soil into ??

A

immediately

rhabditiform larvae
filariform larvae

26
Q

the N. american filariform larvae will seek out ?? in order to ??
then ??

A

a tall blade of grass, etc. to contact human skin

then actively penetrate subcutaneous tissue (hair follicle) and carried via blood

27
Q

N. american filariform larvae are carried via blood to ??
where they ??

similar to ???

A

lungs
break out of alveolar capillaries, cruel up bronchi and trachea over the epiglottis and into pharynx and swallowed

Ascaris “the wanderer”

28
Q

N. american larvae develop into adult worm in the ??

A

small intestine

29
Q

N. americanus symps caused by ??

manifestations ?

A

penetration of larvae
ground or dew itch (allergic reaction): intense itching, burning erythema, edema, papular lesions–>vesicular if sensitized

30
Q

N. american symps not typically caused by ??

unless ??

A

larval migration thru lung (inapparent)

unless heavy worm infestation–>vermis pneumonitis

31
Q

N. american sypms from adults in sm. intestine

depends on ?? and ??

A

loss of blood

worm burden (need 200+)
host nutritional status (related to host Fe++ loss and replacement)
32
Q

light N. american infection typically

A

no recog. symptoms

33
Q

acute/heavy N. american infection

A

heartburn, flatulence, diarrhea, wl, +/- eosinophilia

GI symps disappear if become chronic

34
Q

chronic N. american infection resembles ??

bad symps in kiddos?

A

iron deficiency anemia
fatigue, ha, numbness, tingling, dyspnea, anorexia, hd/ft edema, sexual dysfunction, pallor, tachy, enlarged heart

physical, mental dev. may be arrested

35
Q

N. armerican dx

A

clinical suspicion +
labs: ova in feces, quant. counts for worm burden, CBC looks like infection/iron deficiency (hypochromic RBC, eosinophilia)

36
Q

N. american tx

A

Mebendazole

37
Q

N. american prevention

A
improve sanitary facilities, only poop in toilets!
don't use night soil
wear shoes
education
mass tx
38
Q

Strongyloides stercoralis

A

roundworm
occurs in warms climates like hookworms (N. americanus)
also spread sporadically in temperate climates

39
Q

signif reservoir of Strong ster

A

dogs

40
Q

Strong ster has both a ??

A

free living phase and parasitic cycle

41
Q

Strong free-living phase: larvae are ??

form of larvae ?? will ??

A

pooped out and deposited in soil (unlike hookworms)

rhabditiform larvae will grow and dev. into free-living adult worms

42
Q

Strong free-living phase is

A

diecious, adults mate and female produces embryonated eggs that hatch and undergo similar cycle

43
Q

if poor conditions, the Strong filariform larvae will ??

A

penetrate skin of host and begin parasitic infection

44
Q

initial part of Strong parasitic life cycle:

A

similar to hookworms and Ascaris (spread to lungs, swallowed)
larvae develop into female adults in small intestine

45
Q

Strong female adult is ?? and can live ??

weird brief appearance of ??

A

2 mm (small), lives w.in and among columnar epi cells of sm. intestine
male sex organs–>self-fertilization–>involution of male gonads
no parasitic male per se

46
Q

Strong embryonated eggs hatch in ?? and proceed to ??

where they develop to ?? and are ??

A

sm. intestine–>colon

rhabditiform larvae, pooped into soil

47
Q

if host is constipated, Strong rhabditiform larvae will ??

A

develop into filariform larvae and directly re-infect host by penetrating colon mucosa or perianal area

48
Q

Strong ster: common?

found where ??

A
less prevalent than hookworm
SE USA, rural areas (0.4-4%)
mental institutions (40%)
veterans
immunocompromised pts
49
Q

Strong ster symptoms due to penetration

A

little reaction observed in direct cycle, if auto infected may see creeping eruption at perianal region

50
Q

Strong ster sypms from larval migration thru lungs..

A

few unless large infestation: pneumonitis, peripheral eosinophilia

51
Q

Strong intestinal symps

A

invasion of mucosa, enteritis, tissue damage

52
Q

manifestation of Strong ster infection

A

most asymptomatic
moderate: pain in epigastric region, diarrhea w. alternating constipation
eosinophilia
severe: malabsorption

53
Q

autoinfections of Strong ster may lead to

A

sev. systemic infections, gen. abd pain, shock, fever, G- sepsis

54
Q

Strong steer may cause ?? in immunocompromised host

A

hyperinfection

55
Q

Strong ster dx

A

most difficult roundworm to dx
eosinophilia in 50-80%
look for larvae in feces (vs. ova in feces for hookworm)
serum IgG by ELISA
skin tests
larvae in sputum: agar test, look for worm tracks

56
Q

Strong ster tx

A

Thiabendazole

57
Q

Strong ster prevention

A
same as hookworm: 
improve sanitary facilities, only poop in toilets!
don't use night soil
wear shoes
education
mass tx
58
Q

Visceral and cutaneous larval migrans

A

“lost worms”
cut/subcut condition from skin penetration and transient migration of hookworm larvae form dogs, cats, etc

larvae die once in human host, but penetration/migration causes a “creeping eruption” inflamm. response in skin
-irritating and can become scratched and secondarily infected

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