CSIM1.67 68 Protozoan & helminth Parasitic D/z Flashcards
Giardia - route of transmission, life cycle, clinical features
2 nuclei, flaggella, microscopic parasite.
Faecal oral, contaminated water,
Giardia is contracted by ingesting its cysts. They go to small intestine and become trophozoites which are released. Trophozoites cause damage to gut mucosa, cause diarrhea and malabsorption. Trophozoites form cysts and are released in faeces.
Clinal ft - watery diarrhea, mild abdo pain, bloating, fatigue and gas build up.
Symptoms of cryptosporidia, microspora and isosporal belli
Similar to giardia, diarrhea, abdominal pain.
Entamoeba histolytica - transmission, life cycle, clinical features
Faecal oral, cysts in faecea.
Once ingested, go to gut and release trophozoites.
Clinical ft - most asymptomatic, some invade mucosa cause ulceration and bloody diarrhea and amoebic dysentery.
If invade blood stream, go to liver and cause amoebic liver abscess
Consequences of an amoebic liver abscess
Fever, Jaundice, anaemia and pain right flank
What is myasis?
Myasis is the parasitic infestation of fly-larvae in a mammal (human), while feeding on its tissue.
How does a tumbu fly myasis come about?
Tumbu fly lays eggs in soil, after eggs hatch, larvae come out and find a host.
If they find a host, they penetrate the skin and start developing inside.
Once mature, it unburrows and drops out of the human skin where it continues its life cycle.
How to treat tumbu fly myasis
Cover the entry wound with vaseline to suffocate the larvae
Larvae will crawl out and then use tweezer to extract.
How to prevent tumbu fly myasis?
Iron your clothes!
What organism transmist trypanosomiasis?
Tsetse fly
What is trypanosmiasis also known as?
Sleeping sickness
What is the life cycle of trypanosomiasis?
Saliva of tsetse fly, bites human and lives in various fluid compartment of the human
Multiple within the body and be ready for when the next tsetse fly bites the human
Symptoms of trypanosomiasis?
Primary chancre, local lymphadenopathy, fever, headache, cutaenous edema, itching, myocarditis, jaundice, anaemia, effusions, chronic meningoencephalitis.
Sleep disturbance - sleep day time, restless night time.
What carries leishmaniasis?
Female sandflies.
What species cause visceral leishmaniasis and cutaneous leishmaniasis?
Visceral - L donovani and L aethiopica
Cutaenous - most other species other than the above.
Cause and clinical features of visceral leishmaniasis?
Caused by lymphatic spread of parasite around body
Systemic effects - episodic fevers, rigors, swears, weight loss, malaise, anorexia and hepatosplenomegaly
Skin effects - hyperpigmentation on the face, hands, feet and abdomen
Clinical features of cutaneous leishmaniasis?
Lesion forming around bite, becomes itchy papule which falls off to become an ulcer.
What is ancylostoma duodenale?
AKA hookworm
How is the hookworm transmitted?
Penetrates skin on feet, goes into blood then to GI.
Symptoms of hookwarm infestation?
Itching at entry wound, abdominal pain, anaemia
Descrive ascaris lumbricoides
Round worm, can grow to 1 feet. Grey translucent colour.
How is ascaris lumbricoides transmitted?
Faecal-oral
Life cycle of ascaris lumbricoides
Eggs hatch in GI, larvae grow into adult which can penetrate blood vessels to spread to other organs
Symptoms of ascaris lumbricoides
None, abdominal pain, distension, anorexia, V&D
What 3 species of trematodes cause schistosomiasis?
S. japonicum
S. Mansoni
S haematobium
How is schistosomiasis contracted?
Water infected with the cercariae of the parasites which are released from infected freshwater snails
What is a trematoda?
A flat worm, or a fluke
Life cycle of schistosomiasis parasite?
Released from infected snails in fresh water, penetrate human skin and migrate into blood
Once in blood, go to liver where male and female develop and fertilise.
Migrate to bowel to lay eggs which are excreted in faeces.
What organs are affected by schistosomiasis
Gut and bowel - S mansoni and S japonicum
Bladder - S haematobium
Symptoms of schistosomiasis
Localised itch at point of entry
1-3 weeks incubation, then fever, malaise and myalgia
Further symptoms depend on the species and organs infected
Bladder - haematouria, obstructive uropathy, bladder carcinoma
Gut - hepatsosplenomegaly, varices and colonic polyposis.
What is katayama fever?
Fever, malaise, myalgia
What spreads onchocerca volvulus?
Female blackfly during the day.
Symptoms of onchocerca volvulus?
Hypopigmentation, lichenification, uveitis, keratitis, blindness
What is the characteristics of loa loa?
Resides in the eye and can be seen crossing the cornea
What spreads loa loa
Chyrsops fly
Symptoms of loa loa
Urticaria, pruritis, lymphodema, arthritis, chorioretinis
How is hydatid acquired?
Ingesting an egg from a dog tapeworm called echinococcus granulosus.
What happens after ingesting an egg from echinococcus granulosus?
Eggs hatch and penetrate gut wall, migrate to liver and form cyst (or other organs)
Symptoms of hydatid?
Asymptomatic OR
Slow progressive features like jaundice, pain RUQ, hepatomegaly
Cysts found in other organs will cause organ-related symptoms
Two types of taenia causing organisms? What animal carries which?
T. Solium - pig
T saginata - cattle
How is taenia contracted
Ingest undercooked infested animal, cyst hatch in intestines and grow into long tape worm.
What is especially bad about T solium?
Larvae and spread and form cyst in other organs.
If it goes to the brain it will cause cysticercosis - small brain lesions all over the brain, visible on CT scan.
Symptoms of cerebral cysticercosis
Epilepsy, raised ICP, focal neurology,
How does a guinea worm present?
Adult worm migrates to skin and grows under the skin, erupts as a blister where the worm crawls out of the skin over a few days.
