Final Final Parasite Panic Flashcards
Dibothriocephalus latus/nihonkainse
‘Fish tapeworm’
Worldwide/SEA
Larvae in raw fish –> adults in humans
Humans definite host
GI upset/B12
Praziquantel
Cook/freeze fish
Taenia saginatum
Beef tapeworm - more than 12 primary lateral branches
Asia/Europe
Larvae in beef –> adult worms in humans
Humans definitive host
Asymptomatic
Pass proglottids
Microscopy eggs
Praziquantel
Avoid raw beef/inspection
Taenia Solium
Less than 12 primary lateral branches
Epi:
Worldwide - Americas/Asia
Lifecycle:
Zoonotic - cystercerci
Humans definitive host
Dx:
Microscopy eggs
Tx: Praziquantel
Cystercecosis
Eating embryonated egg of Taenia Solium
Humans are intermediate host
Investigation:
CT and MRI best
Can do serology
Management depends on stage:
1-2 lesions - albendazole mono therapy and AED
2+ lesions - albendazole/praziquantel and AED
Inumerate lesions - steroids and ask for help
If seizures - need AED to continue for at least 6m
Echinoccous granulosus
Zoonotic eggs from dog faeces –> cysts
Humans intermediate host
Cystic disease - liver 70%, lung 20%
Investigations:
Serology
Eosinophilia
Management:
CE1 and 3A - albendazole +/- PAIR
C2 and 3b - surgery and albendazole
C4 and C5 - PAIR contraindicated
Foxy
Alveolar echinoccous
Northern hemisphere
Fox faeces
Eggs –> cysts
Humans are intermediate hosts
behaves like a liver cancer with mets - more aggressive
Investigations:
Serology
Imaging
Radical surgery and Alvendazole
Often very difficult to manage
Hymenolopis nana
Dwarf tapeworm
Faecal oral by ingesting contaminated food
Human auto infection
Asymptomatic
GI upset
Faecal microscopy
Praziquantel and repeat after 10 days
Prevent with good hygeine and avoid contaminated vegetables/grains
Clonorchis siuensis
(Chinese liver fluke)
SE Asia and E asia
Undercooked freshwater fish
cats –> snails –> fresh water fish –> humans are definitive host
Symptom profile:
Fever, urticaria, hepatomegaly
Late = cholangitis, fibrosis, cholangiocarcinoma
Praziquantel treatment +/- surgery
Fasicola hepatica
Worldwide - South America, Europe, Middle East, Asia (less commonly Africa!!)
Sheep/cattle –> snails –> aquatic plants –> humans (humans are definitive host)
Symptom profile:
Asymptmatic
Acutely - fever, abdominal pain, jaundice
Chronic - malaise, chlangitis, pancreatitis, cholecystitis
Ectopic worms - abscess in other tissues
Imaging - USS/CT
Treatment - Triclabendazole
Paragonimus Westerani
Lung fluke
East Asia and Americas
Snails –> crab/crayfish –> humans (definitive host
Symptom profile:
Cough haemoptysis (can mimic TBV clinically and on imaging)
Imaging:
CXR
Eggs in SPUTUM or stool
Can do serology
Tx Praziquantel
Entamoeba histolytica (cannot differentiate between E.dispar)
Cyst in question
Trophozoite in answer with ingested erythrocytes
Cyst from faecal contaminated water/food –> trophozoite in small instestine –> large bowel (can migrate to other tissues, extra luminal disease)
Liver abscess
Dysentry
Can cause fever/weight loss
Diagnosis:
Stool PCR
Fresh stool microscopy x3
Imaging for abscess, PCR aspirate
Tx:
Abscess management
Metronidazole + luminicidal agent (eg paromycin)
Giardia duodenalis (trophozoite on q, cyst on a)
Worldwide - 300 million cases a year
Cysts from faecal contaminated water –> trophozoites in small intestines –> cysts in faeces
Symptom profile:
Incubation 1-2 weeks
Watery diarrhoea
GI upset, weight loss
Chronic diarrheoa associated with weight loss
Dx:
Faecal OCP x3, faecal antigen, stool PCR
Tx:
Metronidazole/tinidizaole/Nitaxonaide
Stained with trichrome
Cryptosporidium (c.parvum, c.hominis)
Worldwide - in 10% stools in LIC
Faecal - oral. Cysts from faecal contaminated water or food
Incubation ~ 7 days
Self limiting watery diarrhoea in most
Omunnocompromised - HIV - can cause chronic diarrhoea
Subsequent malabsorption and wasting
Stool PCR or faecal microscopy AFstain
Tx:
Supportive therapy
Nitaxonaide and paromycin options
Trichunella Spiralis
Ingestion of undercooked meat containing encysted larvae. Larvae released from cysts and invasde the small bowel muscosa where they develop into adult worms. Larva are deposited in mucsa and encyst in striated muscle
Gi symptoms
Larval migration to muscle tissues and encystment can cause myalgia and weakness
Can get life threatening manifestations if larval encysts,ent in muscles such as Mycoardiaum/CNS/respiratory
Albendazole is treatment
Toxocara (T canis or cat)
Worldwide, increased prevalence in tropics. Children
Zoonotic nematode - larvae in human (cannot mature)
1) Visceral migraines (any sx possible)
2) Occular migrans - mimic retinoblastoma, unilateral vision loss
Mostly self limiting
Severe - albendazole and steroids
Prevention is treat ya bladdy dogs
Mansonella Perstans
<200 uM
M.perstans (nuclei to end and big one) and M.ozzardi (empty tail)
SS Africa and C/S America
Vector - midges or black fly
Illness - mild/asymptomatic
Non-specific symptoms including fever, fatigue, pruritus, arthralgias, and abdominal pain may occur.
Doxy
Ivermectin/Albendazole/DEC are options
