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Parasites > Trematoda > Flashcards

Trematoda Flashcards

1
Q

Waar komt Schisto het meeste voor?

A

85% van de gevallen in Sub-saharan africa; S. mansoni in Brazilie; S. haematobium en mansoni in SS Africa en S. japonicum in ZO-Azie

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2
Q

Hoe veel gevallen van Schisto zijn er jaarlijks?

A

207-240 miljoen gevallen, 800 miljoen at risk; 3-70M DALYs verloren –> het heeft ernstigere pathologie dan Ascaris, maar minder gevallen;
300-400 nieuwe gevallen per jaar in NL (reizigers en expats, migranten van endemische gebieden)

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3
Q

Wat is de levenscyclus van Schisto?

A

Schistosoma eggs are eliminated with feces or urine, depending on species image . Under appropriate conditions the eggs hatch and release miracidia image , which swim and penetrate specific snail intermediate hosts image . The stages in the snail include two generations of sporocysts image and the production of cercariae image . Upon release from the snail, the infective cercariae swim, penetrate the skin of the human host image , and shed their forked tails, becoming schistosomulae image . The schistosomulae migrate via venous circulation to lungs, then to the heart, and then develop in the liver, exiting the liver via the portal vein system when mature, image image . Male and female adult worms copulate and reside in the mesenteric venules, the location of which varies by species (with some exceptions) image . For instance, S. japonicum is more frequently found in the superior mesenteric veins draining the small intestine image , and S. mansoni occurs more often in the inferior mesenteric veins draining the large intestine image . However, both species can occupy either location and are capable of moving between sites. S. intercalatum and S. guineensis also inhabit the inferior mesenteric plexus but lower in the bowel than S. mansoni. S. haematobium most often inhabitsin the vesicular and pelvic venous plexus of the bladder image , but it can also be found in the rectal venules. The females (size ranges from 7–28 mm, depending on species) deposit eggs in the small venules of the portal and perivesical systems. The eggs are moved progressively toward the lumen of the intestine (S. mansoni,S. japonicum, S. mekongi, S. intercalatum/guineensis) and of the bladder and ureters (S. haematobium), and are eliminated with feces or urine, respectively image .

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4
Q

Zijn Schisto parasieten hermafrodiet?

A

Unlike other trematodes, which are hermaphroditic, Schistosoma spp. are dioecous (individuals of separate sexes).

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5
Q

Hoelang leven adulte schisto wormen?

A

5jaar (sommige gevallen 40jaar oud!)

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6
Q

Incubatieperiode van schisto?

A

5 weken totdat het de venen bereikt - geen eiproductie maar kan al symptomen vertonen

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7
Q

Klinische presentatie van schisto?

A

A. dermatitis (swimmers itch) (vaker in reizigers of in de 1e/2e blootstelling)
B. acuut (Katayama fever) - algemene malaise en koorts, eosinophilia (niet altijd), respiratoire klachten (door passage door de longen)
Katayama can be mistaken for malaria
C. Chronisch - granuloma vorming (meer granuloma meer pathologie), collageen depositie (+ orgaanfalen)

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8
Q

Morbiditeit van schisto in endemische gebieden?

A

Uro-genitale schisto (S. haematobium)

  • bloed in terminale urine of hele urine is rood
  • blaas/ nierfalen (vaak na een aantal jaar)
  • squamous blaaskanker
  • genitale presentatie (Female/ Male Genital Schisto)

Intestinale en hepatische schisto

  • granulomateuze inflammatie leidt tot bloederige diarree
  • vergroting van bowel en rectum
  • (spleno) hepatomegalie (moeilijke differentiatie met chronische malaria)
  • portale hypertensie, bloedende varices (fibrotic hepatic schisto) (kan levensbedreigend zijn, maar pas na een langere termijn)
  • S. japonicum is snellere ontwikkeling
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9
Q

Diagnosis van schisto?

A

Microscopie!
Directe smear is vaak heel insensitief door laag aantal eitjes! –> concentratiemethode nodig!
Urine filtratie
Kato-slides
Glycerine sedimentatie (larvae blijven leven in eitjes)
Formalin ethyl acetate concentration

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10
Q

Wat zijn de verschillen in de Schisto eitjes?

A

S. haematobium: spine at the end (140-60um)
S. mansoni: spine at the side (140-60um)
S. japonicum: no spine/ uitsteeksel aan de zijkant (85-65um)
S. intercalatum: spine at the end, not really oval shaped (140-60um)

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11
Q

Methodes voor stoelgang examinatie voor Schisto?

A

Directe fecale smear –> insensitief
Formol-ether concentratie methode (Ridley) -> concentratiemethode maar geen verschil tussen levende of dode eitjes
Glycerine-water sedimentatie –> groter volume van feces (meer sensitief), eitjes zijn nog steeds leefbaar (post-treatment monitoring)
Kato-slide examinatie (Kato-Katz) –> 25mg stoelgang - eggs per gram (voor kwantitatieve veldstudies)

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12
Q

Methodes voor urine examinatie voor Schisto?

A

Glycerine urine sedimentatie methode

  • sensitiviteit hangt af van het protocol van staalcollectie:
    1. moment van collectie (rond de middag!)
    2. urine volume
    3. fysieke inspanning!
    4. laatste druppels van de urine

Syringe filtratie methode (10ml) (eitjes blijven op de filter):
- kwantitatieve veldstudies (surveys)

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13
Q

Waar vind je S. haematobium eitjes?

A 
In urine (cellen in urine plakken aan de eitjes, vooral WBC)
In semen! --> bloederig sperma
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14
Q

Wat is Female Genital Schisto?

A

Hypertrofe en ulceratieve lesies, afhankelijk van de locatie van de worm (vulva, vaginaal, cervix mucosa)
Pijnlijke pelvis, jeuk, discharge, vesico-vaginale fistulae
Sandy patches en contact bloeding

Leidt tot stigmatisatie, kan leiden tot onvruchtbaarheid, vergemakkelijkt STDs en HIV

Ook in reizigers!

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15
Q

Hoe wordt Schisto behandeld?

A

Praziquantel (40mg/kgbw)
Nationale control programs: population based treatment:
- preventieve chemotherapie
- MDA

PZQ is niet voor jonge wormen (wacht tot 12 weken na blootstelling!); in prepatente infectie - behandeling moet herhaald wordne in 2-3 weken

niet-endemische gebieden:

  • betere behandeling rates door hogere dosis/ herhalingen
  • 60mg/kgbw in 2-3 dosissen; 2e behandeling na 3-6 weken

PZQ met steroiden in geval van acute symptomen
artemeter, artesunate voor immature stadia (malaria drugs)

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16
Q

Alternative diagnosis voor Schisto?

A
  • Haematurie sticks (niet sensitief genoeg in lage transmissie gebieden)
  • Ultrasound (voor morbiditeit monitoring, maar niet common)
  • serologie (common; beperkingen, specifieke groepen (reizigers/ gecontroleerde gebieden) - in controlled human infecties (inf met mannelijke worm!) aangetoond dat 100% van de gevallen seroconverteren na 5 tot 6 weken maar blijven + jaren na infectie) - optimale test in early detectie van acute schisto
  • circulerende antigenen (excretie in de urine) voor epidemiologische surveys (RDTs voor S. mansoni)
  • PCR op klinische stalen NAAT (DNA detectie test) (meer en meer gebruikt/ epidemiologische surveys/ quality control op microscopie)
17
Q

Wat zijn de foodborne trematoda?

A 
Chlonorchis sinensis
Fasciola hepatica
Paragonimus westermani
Opistorchis viverrini
Fasciola gigantica
Echinostoma spp.
Fasciolopsis buski
Gymnophalloides seoi
Haplorchis spp
Heterphyes spp
Metagonimus spp
18
Q

Wat is de bron van infectie van Chlonorchis sinensis?

A

Freshwater fish

19
Q

Wat is de bron van infectie van Opistorchis spp?

A

Freshwater fish

20
Q

Wat is de bron van infectie van Paragonimus spp?

A

Freshwater crabs, crayfish, wild boar meat

21
Q

Wat is de bron van infectie van Echinostomatidae?

A

Freshwater fish, frogs, mussels, snails, tadpoles

22
Q

Wat is de bron van infectie van Gymnophalloides seoi?

A

Oysters

23
Q

Wat is de bron van infectie van Heterphyidae?

A

Freshwater fish

24
Q

Wat is de bron van infectie van Fasciola spp?

A

Freshwater vegetables, contaminated water

25
Q

Wat zijn de liver flukes?

A

Chlonorchis, Opistorchis, Fasciola

26
Q

Wat zijn de lung flukes?

A

Paragonimus

27
Q

Wat zijn de intestinal flukes?

A

Echinostoma, Fasciolopsis buski, Gymnophalloides seoi, Haplorchis, Heterophyes, Metagonimus

28
Q

Wat is de behandeling voor flukes?

A

Praziquantel - voor Fasciola triclabendazole! (vooral behandeling voor Fasciola is niet altijd simpel!)

29
Q

Wat is de levenscyclus van fasciola hepatica/gigantica?

A

Immature eggs are discharged in the biliary ducts and passed in the stool.
Eggs become embryonated in freshwater over ~2 weeks; embryonated eggs release miracidia, which invade a suitable snail intermediate host. In the snail, the parasites undergo several developmental stages (sporocysts, rediae, and cercariae). The cercariae are released from the snail and encyst as metacercariae on aquatic vegetation or other substrates. Humans and other mammals become infected by ingesting metacercariae-contaminated vegetation (e.g., watercress). After ingestion, the metacercariae excyst in the duodenum and penetrate through the intestinal wall into the peritoneal cavity. The immature flukes then migrate through the liver parenchyma into biliary ducts, where they mature into adult flukes and produce eggs. In humans, maturation from metacercariae into adult flukes usually takes about 3–4 months; development of F. gigantica may take somewhat longer than F. hepatica.

30
Q

Wat is de symptomen van acute fasciola?

A

Abdominale pijn, (koorts), eosinophilia!!!

31
Q

Diagnose van Fasciola?

A

Microscopie gouden standaard

32
Q

Hoe groot is de adulte worm van Fasciola?

A 
hepatica = 3.5cm
gigantica = 7.5cm
33
Q

Wat is de levenscyclus van Opistorchis?

A

O. viverrini = SE-Asian liver fluke
O. felineus = cat liver fluke

The adult flukes deposit fully developed eggs that are passed in the feces. After ingestion by a suitable snail (first intermediate host) , the eggs release miracidia , which undergo in the snail several developmental stages (sporocysts , rediae , cercariae ). Cercariae are released from the snail and penetrate freshwater fish (second intermediate host), encysting as metacercariae in the muscles or under the scales . The mammalian definitive host (cats, dogs, and various fish-eating mammals including humans) become infected by ingesting undercooked fish containing metacercariae. After ingestion, the metacercariae excyst in the duodenum and ascend through the ampulla of Vater into the biliary ducts, where they attach and develop into adults, which lay eggs after 3 to 4 weeks . The adult flukes (O. viverrini: 5 mm to 10 mm by 1 mm to 2 mm; O. felineus: 7 mm to 12 mm by 2 mm to 3 mm) reside in the biliary and pancreatic ducts of the mammalian host, where they attach to the mucosa.

34
Q

Kan serologie gebruikt worden als diagnose voor trematoda?

A

Ja voor vroege diagnose; hoge sensitiviteit, goede specificiteit, goed voor follow-up na behandeling
Fasciola –> commerciele ELISA, recombinant Ag

Parasites (9 decks)

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