INTESTINAL PARASITE

Helminths Trematoda Cestoda

Heterophyes heterophyes(intestinal fluke)

Diphylobothrium latum(broad/ fish tapeworm)

Tenia saginata(beef tapeworm)

Tenia Solium(pork tapeworm)

Hymenolypis nana(dwarf tapeworm)

Geograpgical distribution Egypt & Far East Lake area of central Europe, central Africa, North America, Far East*not in Egypt

CosmopolitanEthiopia, Mexico,South America,East & West Africa

Cosmopolitan*rare in Islamic country

Cosmopolitan*more in warm climates

Habitat D.F : small intestine of manreservoir : cats, dogs, fish eating birds

D.F : small intestine of manReservoir : fish eating mammals(cat, dogs, bears

D.F : small intestine of man (the only)*scolex attached to mucosa, the rest folded

Small intestine of man Small intestine of man

Size Length : 1.5-3 mmBreadth : 0.5 mm

10 meters />

*3000-4000 segments

4-10 meters (usually 5)

*1000-2000 proglottids

3-8 meters

*1000 segments

Length : 20-60 mmBreadth : 1 mm*100 segments

Scolex - Elongate (length: 1mm) spoon shape,2 longitudinal bothria/groove

Quadrate (diameter: 2mmUnarmed

4 strong hemispherical suckers

GlobularRostellum armedDouble row of hooks4 suckers(cikgu ckp)

RhomboidalShort rostellum armed20-30 spines in single row4 suckers

neck - + + (thin neck) + + (long & slender)

Mature segments Broader than longMid ventral genital pore4mm (L) X 12 mm (B)Testis : multiple, dorsolateralVas deferens>seminal vesicleCirrus, ootype, vagina: open in common genital poreBilobed ovary (posterior)

Broader than long

300-400 testis

Vagina with terminal sphinter

Bilobed ovary

150 testis

Trilobed ovary

3 globular testis (in one line)

One small lobe ovary

Vitelline glands (ventrolateral)Uterus: coiled rossete shapeOpen in uterine pore below common genital pore

Blind tubular uterus

Vitelline glands

Uterus : middle part of segment

Gravid segments Same as mature segment*egg continuously discharged from uterine pore

Uterus : darker, more coiled, rossete shape, pack with egg

Elongate & rectangular2X7mm (L X B)

Lateral side branch of uterus : 15-20

Usually detached singly from parent worm> very active-creep out of anus even without defecate

Lateral side branch of uterus : 7-13

Sac like uterus with 80-100 eggs

*segment usually rupture liberating egg in intestine

Eggs Pass in faecesImmature, ovoid, operculatedYellowish brown65x45micMust reach fresh water to mature

Cannot differ from other teniaMature, spherical30-42mic*Thin hyaline capsule –shed after leave proglottid*Thick brown striated embryophore surround hexacanth embryo/oncosphere

Indistinguishable from T.saginata

Oval/sphericalColorless40mic diameter2 thin shellInner shell:embryophore has 2 knob at opp. Side-arise 4-8 filamentsInside embryophore: hexacanth embryo

Intermediate host 1st : Pirenella conica (Rt. Handed snail2nd : Mugil cephalus (Boury) &Tilapia nilotica (Bolty)

1st : Cyclops / diaptomus(crustacean copepod)2nd : fresh water fish (perch, salmon, trout)

- PigsMan causing cysticercosis

Infective stage Encysted metacercariae Plerocercoid larvae Cysticercus bovis Cysticercus cellulosae Eggs are immediately infective

Mode of infection Eating imperfectly cooked fish/undersalted fish(sweet fessikh-salted <7days)

Eating raw / insufficiently cooked flesh / fish

Ingesting infected meat Ingest imperfectly cooked pigs meat

Ingestion of eggs in contaminated food/drinkOR autoinfection

Pathogenesis & pathology -Mild catarrhal inflammation-Superficial ulcer-necrosis

Depends on no of worm*competition for nutrients B12 & metabolic by products absorbed by host

Often cause change in motility & secretion of GIT than pathological*reduce gastric secretion (70%)

Slight irritation at their site of attachment to mucosaRarely intestinal obstruction

Well tolerated even in large no.

*Symptoms > allergic

Clinical pictures Mild : asymptomaticHeavy :-abdominal colic,-chr. Intermittent diarrhea-blood in stool-Myocarditis, heart Failure-encephalitis

Usually assyptomatic-diarrhea, abdominal pain,-pernicious anemia (small in genetically predisposed)Multiple worm : intestinal obs.

-vague abdominal pain-nausea-</> appetite,body weight-weakness-insomnia-irritability-abdominal discomfort(due to active crawling of proglottid from anus)-allergy(rare)

-vague abdominal discomfort-hunger pain-diarrhea-diarrhea alternating with constipation-loss of appetite

Usully asymptomatic-headache-dizziness-anorexia-periodic diarrhea-abdominal pain

Complication Multiple worm : intestinal obs.

-intestinal obstruction-sporadically straying : acute/ subacute appendicitis / cholangitis

Diagnosis Eggs in stool Eggs/ segments in faeces Gravid proglottid in faecesEggs (rarely finding)*teniasis : most difficult to diagnose in 1st 3 months of infection (x egg, x proglottids discharged)

Gravid segment in stoolRarely egg*egg xblh diff. dgn T.saginata (except kira lateral branch)

Egg in stool

Treatment Praziquantel orally Niclosamide (Yomesen)-morning, empty stomach, well chewed-strobila often evacuated-if not use purgativePraziquantel

Niclosamide (Yomesen)Praziquantel

Niclosamide (Yomesen)Praziquantel

Niclosamide-5-7 days :kill adultPraziquantel-systemically abs.-act on: cysticercoid in villi Adult in lumen

Prevention & control -X eat raw/imperfect cook fish-molluscicides : ineffective (Pirenella conica is operculated)

-thorough cooking of fish-freez 24-48h at -18C to kill plerocercoid-dewormed periodically RESEVOIR HOST (dogs,cat)

-X eat RAW / imperfect cookedLight infection : consumed after freezing at -18C for 5days-early detection & treat. Of human teniasis (helpful)-condemn/boil carcasses with intensive cysticerci