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Nematodes classical
Question | Answer |
---|---|
Threadworms/pinworm: Latin name Mode of transmission Symptoms Treatment | Enterobius vermicularis Faeco-oral transmission (ingest egg- gravid female deposits eggs perianally) Itching Tx: albendazole/ mebendazole |
Whipworm: Latin name Mode of transmission Confection Treatment | Trichuris trichiura Feaco-oral transmission from soil (eggs to mouth. remain in colon/rectum) May get confection with ascaris or hook worms and pain/vomiting/weight loss. Heavy burden -haemorrhage, prolapse,enteropathy,aneamia Tx:Alb/mebendazole |
Roundworm: Latin name Mode of transmission Symptoms Treatment | Ascaris lumbricoides Faeco-oral. Migrates from gut to lungs (through bloodstream), swallowed and remains in gut. Tx: albendazole, mebendazole |
Ascaris lumbricoides: Symptoms / complications | lungs- lofflers syndrome: wheeze/eosinophil/patchy CXR- Prednisolone Ectopic cns migration. Anaemia,malabsorb(A+C)fats/lactose. Growth retard, cog impair Bowel obstruction Bile/pancreatic obstruction Peritoneal granuloma High fever- vomit worms |
Hookworms: Latin name Mode of transmission Symptoms | Ancylostoma duodenale/ceylanicum./Necator americanus Faeco-cutaneous transmission hatch in stool, T3penetrate skin, blood vessels to heart then lungs then swallowed to jejunum. Last 1-2yrs. Ancylostoma larvae can also be ingested Anaemia/growth retard |
Classical worms with no Eosinophilia? | Enterobius vermicularis- thread/pin Trichuris trichiura- whip No tissue migratory phase, no eosinophilia |
Threadworm (roundworm) Latin name Transmission Treatment | Strongyloides stercoralis/ strongyloides fuelleborni Faeco-cutaneous transmission Can recur for years. Can cause recurring gram neg sepsis-larva pulls bugs through gut wall Treatment ivermectin |
Larvae currens: Free living lifecycle of causative parasite | Freeliving: rhabditiform larvae in stool. Infective filariform (direct)or free living males/females mate. Eggs develop into filariform larvae penetrate human host to initiate parasitic cycle. Cannot then mature to free living adults |
Larvae currens: Parasitic lifecycle of causative parasite | Strongyloides stercoralis. Filariform larvae in soil penetrate skin migraine to small intestine. Becomefemale adults in submucosa eggs via parthenogenesis yeild rhabditiform larve. Into stool/cause autoinfection as filariform- can be persistent. |
Larvae Currens vs cutaneous larva migrans | Cutaneous Migrans: doog hookworm(ancylostoma braziliense) stays for days Currans: strongyloides stercoralis lasts for 30mins |
Dog hookworm: Symptoms Treatment | Ancylostoma braziliense Causes cutaneous larva migrans Same as hookworm but larva can't migrate further than under skin. Soon dies. Treatment: ivermectin |
Guinea worm Transmission Treatment | Dracunulus mediensis L3 larvae ingested in copepods (water or fish) Fertilised female travels to limb 1yr: blister. Remove carefully |
Visceral larva migrans causative Parasites | Toxocara (t. Canis for occular) -albendazole/mebendazole Gnathostoma- albendazole/ivermectin Angiostrongylus cantonensis- meningitis. Treatment harmful. Support with steroids Painful. Body/eyes/skin. Eosinophilic meningitis. |
Toxocara Transmission Symptoms Treatment | Cats/dogs faeces unembryonated egg. L3 ingested humans (accidental host) from faeces/undercooked meat/viscera of paratenic hosts (duck,rabbit) hatch Larvae migrate all tissues cause local reactions+ damage (toxicariasis). Dead end host. Al/mebendazole |
Gnathostoma: Transmission Treatment | Hosts-pig/cat/dog. Worms in intestinal mass. Eggs pass and embryonate in water sheathed L1 ingested by copepods, L3 develops in second host (fish/frog). Humans eat second host or paratenic host. Migrate in humans various tissues. Dead end host. |
Angiostrongylus cantonensis Areas Transmission Symptoms | SEAsia, Africa, Australia, Caribbean. Definitive host rat- eggs in faeces intermediate host snail L3 larvae produced. Infect humans (ingest gastropod/larvae) migrate to brain become young adults mature in venous system/pulmonary arteries. Dead end host. |
Trichinellosis: Transmission Symptoms Treatment | Trichinella spiralis. Domestic (pigs) sylvatic (bears). Humans ingest meat containing cysts, larvae released develop adults in s.bowel mucosa. Female larvae to muscles- encyst. Naus/pain/fever/myositis. Tx meb/albendazole |