Trematodes - Schistosoma, Fasciola, Paragonimus... Flashcards
Schisto species and geography + targeted pathology
- S haematobium - urogenital- Africa and Middle east. Haem / albumin urea [Eventually fibrosis and obstructive uropathy]
- S mansoni bowel and LIVER- Africa and South America (due to slave trade) diarrhoea and blood
- S japonicum - bowel and liver + CNS in 4% - China, and South East Asia
-S mekongi (similar to japonicum only found in Laos / cambodia)
Shisto appearance
Worms 1-2cm long look like a rolled leaf
Basic life cycle of all shisto? How does this affect where eggs are found
- Eggs released from human stool / urine
- Hatches in FRESHwater after 1-3 weeks to release a miracidium (L1 stage)
- Snails which live in water - intermediate hosts
- Sporocyst in snail release cercariae (L3) into water (0.2mm long) in response to light
- Penetrates through skin [Days 0-2]
- Reaches lungs Day 3-10 then to liver [3+ days]
- liver -> mature fluke (L5) in mesenteric vein [4+ weeks] where mature males and females couple (forever)
haematobium - lives vesicle plexus and eggs pass through wall into bladder
Mansori / japonicum - Live in portal veins and eggs pass through bowel wall into stool
Which shisto is most zoonotic?
Japonicum- reservoirs in farmed mammals
Transmission of schisto usually very local. Who has most egg output
Children 10-15 Years
[They the ones swimming most]
Bar lakes where is other key water for shisto to infect humans
Domestic if water supplied contaminated
Acute shisto also called? What happens? when?
- Katayama fever
- Diarrhoea, hepato/splenomegaly, cough/wheeze, urticaria fever and eosinophilia
Approx 4-8 weeks after infection
What is swimmers/fisherman’s itch cased by? real name and how long does it last?
Shitsto occasionally occurs where cercariae enter skin
Cercarial dermatitis - can last several days
4 complications with s haematobium?
Eggs may cause fibrosis and calcification
-> May lead to ureteric obstruction
Increased risk of bladder squamous cell Ca
Female sterility
Eggs obstructing pulmonary arterioles -> R heart failure
S mansori/ japonicum key issue? Seen on imaging?
- Periportal fibrosis -> varices
- ‘Pipe stem fibrosis’ on US
Definitive dx shisto? How to work out which species
- Microscopy of eggs
- Gives an idea of degree of infection eg >50 eggs /g of stool
-Western blot for species (but Rx the same)
Dx of neuro shisto
Brain imaging with serodiagnosis
Shisto rx
Praziquantel single dose 40mg/kg
- add steroids if katayama fever
[Artemisinin can be used as ‘morning after pill’ as need to wait 8 weeks for prazi]
Shisto control
- Kill snails by eg draining water, or use a molluscuside eg niclosamide
- Health education
- Mass chemo with praziquantel - targeting kids
How can you monitor shisto haematobium incidence rates without having to use blood tests
- Prevelance of haematuria
- Point of care urine antigen dipstick
What do all trematodes have in life cycle
Snail
Which snail for 3 types
Too hard don’t care
What is the infectious L3 form of schisto
Cercariae - this is the infectious stage
[Full mature adult is never the infectious stage]
Whats cute about schisto
Males and females mate for life
S mansori egg in liver what happens
When egg breaks down -> proteins causes immune reaction (IL-2/5 -> granuloma -> fibrosis
Buzzword for mansoni pathology cauing morbidity
symmer’s periportal fibrosis [pipestem firbrosis]
Key difference between Katayama fever and malaria in returning traveller
Katayama - eosinophilia
Neuroschisto caused by which? Paraplegia?
S Japonicum in 4% of untreated cases -> neuro
S. Haematobium - due to backflow of eggs into spinal cord -> paraplegia
Variceal bleeding in which schisto
Mansoni and Japonicum
Swimmers itch in the US due to
Avian schisto (only causes local cutaneous infection)
The cercariae looking for ducks and doesn’t cause more issues for humans
Katayama fever how to make dx of schisto
Eosinophilia + clinical and Hx (fresh water exposure 4-8 weeks ago)
Katayama fever how to make dx of schisto
Eosinophilia + clinical and Hx (freshwater exposure 4-8 weeks ago)
Whos got big eggs
Trematode Eg Schisto
Japonicum and mejongi eggs differ from mansori by?
Smaller, rounder with a little knob on the side
Praziquantel kills what stages of schito ? Relevance of this
Adult worms only
[Therefore in pre-patent phase would not clear schisto infection]
Need to wait 8 weeks after exposure
Rx Katayama fever
Short course high dose pred - for 3-6 days
Praziquantel after 6 weeks [when worms are mature]
What common co-infection associated with schisto
Salmonella in urine = schisto
[Hepatitis
HIV (especially if genital disease]
trematodes are known as? Usual Rx?
Flukes
Praziquantel
[If Fasiciola hepatica or F. Gigantica (both liver flukes)- Triclabendazole]
what are trematodes? Usual rx?
Flukes
Praziquantel
[if liver flukes - Triclabendazole]
2 main types of liver fluke? Geography and life cycle?
Fasciola hepatica: worldwide where there are sheep, Peru esp in highlands
Fasiola gigantica: africa, west Asia, South America
2intermediate hosts
snail (lymnae snail)
Plants (which are eaten by human eg watercress)
Infectious state: metacercariae
Consumption of these plants eg watercress or contaminated water
Enter through duodenum and migrate to liver into bile ducts where they mature
Liver fluke clinical features? when?
Fasciola hepatica
6-12 weeks after infection
General abdo symptoms and tender hepatomegaly
-Increased risk of cholangitis or intermittent biliary obstruction
-marked eosinophilia
-leukocytosis
-pulmonary infiltrates
Ix liver flukes
Eosinophilia
CT - multiple hyperdense lesions
EIA, Immunoblot
Lateral flow
Serology - eg Fas2-ELISA
Fasciola excretory-secretory (FES) antigen in faeces
[Stool eggs only present in chronic disease usually]
Rx Fasciola hepatica or F. Gigantica? key side effect?
Triclabendazole 10mg/kg single dose
Get biliary colic after 3-7 days due to expulsion of dead flukes
[fashion trick]
Which oriental liver fluke china? Thailand? - diffence in their life cycle to other liver flukes? Complication?
Clonorchis sinensis (china)
Opistorchis viverrini (Laos Thailand)
Opistorchis felineous (Russia)
Infect fresh water fish (carp) rather than plants -> transmitted by eating fish
Ascend the bile ducts, eosinophilia, chronic obstructive picture, cholangiocarcinoma
Oriental liver fluke dx? rx?
Characteristic eggs in faeces / biliary aspirate
Can use US / ERCP
Praziquantel 40mg/kg single dose
Key intestinal fluke? Geography ? sx? Rx
Fasciolopsis Buski
India through to SE asia especially pig rearing
Cause ulceration / chronic Gi Sx
Praziquantel ….
Clinical features paragonimus ? Seen on imaging? Common complications?
Malaise, shivers, sweats and rash
-Key is chronic cough with haemoptysis
-Peripheral nodules / ring shadows on XR
-Prominent eosinophilia
Subcut migratory nodules common
Effusion/empyema
Cerebral/spinal disease**
[Can get egg granulomas in many organs]
Paragonismus dx? Rx?
Sputum / faeces microscopy
Eosinophilia
ICT test - rapid
ELISA, Immunoblot [if available]
Praziquantel for 2-3 days
[Or Triclabendazole]
-Surgical removal of extrapulmonary lesions
Most common paragonimus species worldwide?
Paragonimus westermani
Life cycle of hermaphroditic trematodes
Eggs hatch in water -> miracidium
Enters snail -> sporocyst
sporocyt develop into redia
Redia turn into cercariae which enter water and either
-Infect fish
-Crustacean
-Attach to plant
Become metacercariae
41 yo male
* 30 d of chills, fever at night, moderate sweating
*Abdominal pain in epigastrium and RUQ, increases with
meals
*Wt Loss 5 Kg
Distended, diffuse tenderness to superficial palpation; pain and muscular guarding in epigastrium and RUQ to deep palpation
Fasciola hepatica or gigantica
Fasciola hepatica gigantica definitive host
: Sheep, cattle
Fasciola life cycle
fAsciola egg
Fasciola what are these
Redia on left, cercaria on right
Most common sx fasciola? Blood finding?
Abdo pain
Significant eosinophilia
Most important complications fasciola?
Sclerosing Cholangitis (fever, jaundice)
Biliary sclerosis
[Pancreatitis, haemobilia / anaeemia
-Migrating Blood vessels, lung, peritoneum, intestinal wall, Muscles, eyes, brain, testes]
Diagnosis chronic phase fasciola
Serology: CIEF for copro-antigens (3-4 w before eggs)
Fas2 serology
Western blot
Eggs in stool
Clonorchis sinensis and Opistorchis viverrini / felineus life cycle
Clonorchis sinensis and Opistorchis viverrini / felineus key blood finding in acute infection
Raised ALP
Clonorchis sinensis and Opistorchis viverrini / felineus key complications
Same as fasciola
- Obstructive jaundice
-Recurrent ascending cholangitis
-Cholecystitis - Pancreatitis
- Gallbladder or intrahepatic stones
Specific to Clonorchis sinensis and Opistorchis viverrini
- Night blindness
- Cholangiocarcinoma
Clonorchis sinensis and Opistorchis viverrini Dx? Rx?
Eggs in stools
ELISA - fecal antigen / antibodies
Praziquantel
Which is the biggest intestinal fluke? Definitive host?
Fasciolopsis buski
Pigs
Fasciolopsis buski life cycle
Basically same as fasciola
[Pigs implicated instead of other livestock]
Fasciolopsis buski Key pathology?
Small bowel mucosa: Inflammation, mucus,secretion, ulceration.
Bleeding, abscess formation.
[fowl smelling diarrhea, undigested food
* severe abdominal pain
* fever, eosinophilia
* malabsorption, hypoalbuminemia, low
serum levels of vitamin B12
* oedema, ascites, anasarca]
Fasciolopsis buski Ix Rx
Stools - Eggs
Praziquantel
Paragonimus westermani egg
Which paragonimus in Latin america?
P. mexicanus
Westermani more in asia
Paragonimus Intermediate vs definitive host
1st intermediate - snails
2nd - crayfish
Definitive - animals eating
Paragonimus life cycle
How do you get infected with paragonimus
Consume uncooked crab/crayfish with metacercariae
CXR sign in paragonimus called?
Soap bubble appearance
Paragonimus egg
Schisto life cycle
Found in stool =
Schistosoma mansoni - has a lateral spine
Schistosoma mansori
S. Hematobium Ova in Stool
Terminal spine
Which schisto
S. Japonicum or S. Mekongi;
smaller, round, with small lateral knob
Only trematode which isn’t eaten by a snail (directly infects)
Fasciola
Acute vs chronic fasciola ix?
Acute - hypereosinophilia >1500
-no eggs in stool
- serology positive after 2-3 weeks (Fas2 ELISA)
Chronic - mild eosinophilia
- Microscopy positive after 3-4 months
Spell 2 liver, 1 lung, 1 blood and 1 intestinal fluke
Liver fluke
-Fasciola hepatica / gigantica
-Clonorchis sinensis
- Opistorchis viverrini
Lung
- Paragonimus westermani
Blood
-Schistosoma mansori
Intestinal
-Fasciolopsis buski
What are all flukes? bar?
Hermaphrodites
-Bar schisto
How do humans get infected by trematodes
Eating host/plants with metacercariae (except schisto)
Fasciola life cycle?
Infective vs diagnostic? Name the hosts?
Infective stage : metacercariae
Diagnostic stage : unembryonated egg
Intermediate host : snail
Definitive host : ruminants , humans
Key food for fasciola hepatica
watercress
Fasciola hepetica - note CEPHALIC cone
[herpetic cone of shame]
Fasciola hepatica - note CEPHALIC cone
[herpetic cone of shame]
130um big
Faciola hepatica
How big am I?
Fasciola hepatica
120-140um
Faciola hepatica vs fasciolopsis buski
Cephalic cone?
Which one can be 7cm?
Oral and ventral suckers distance?
fasciolopsis buski life cycle
Clonorchis sinensis life cycle?
Clonorchis sinensis
or O. viverreni
Knob on side
Clonorchis sinensis
-Lateral branches
[S - wavey side to side]
opisthorchis viverrini
- No lateral branches
[V - remains straight line down middle]
Paragonimus life cycle? Infective vs diagnostic?
Hosts?
Infective stage: metacercariae
Diagnostic stage : unembryonated egg
(sputum or stools if swallowed)
1 - intermediate host : snail
2 -intermediate host : crustacean
Definitive host : human
Paragonimus metacercariae
- note the central (ventral) sucker
Paragonimus
no cephalic cone
oral and ventral suckers
Paragonimus
no cephalic cone
oral and ventral suckers
Paragonimus egg
‘shoulders, thickened end (no knob)
Paragonimus egg - its in sputum obvs.
‘shoulders, thickened end (no knob)
Schistosoma life cycle? Infective vs diagnostic? Hosts?
Infective stage : cercariae
-penetrate skin)
Diagnostic stage: egg
-in feces or urine
Intermediate host: snail
Definitive host : human
Where would you find me?
Faeces - Schistosoma mansoni
-Lateral spine
Where would you find me?
Urine - Schistosoma haematobium
-Your willy is in the middle = mid line spine for urine]
Where would you find me?
Faeces - Schistosoma japonicum
Rounded, small lateral spine
[Lateral spine = poo idk]
Male and female Schistosoma
[male is bigger]
Schistosoma cercaria (infective stage)
Fasciola vs paragonimus vs Dyphillobothrium egg sizes? other distinguishing features?
Fasiola - 130um
-often ‘open’
Paragonimus - 100um
-‘Shoulders’, asymetrical and thickened end
Dyphillobothrium - 60um
-Little knob
Freshwater exposure lake Malawi now eosinophilia and urticarial rash ix? Rx? What are the most common symptoms?
Steroids - Katayama fever
Serology - eggs undetectable this early
Praziquantel 6 weeks after exposure
Eosinophilia
Fever
Cough
(rash)
Paragonimus incubation time after infection -> chest sx
4-6 weeks
