Organism adn Disease

Organism/disease Spread Ascaris lumbricoides → Ascariasis Faecal-oral Trichuris trichuria → Trichuriasis Ingestion of eggs Ancylostoma duodenale, Nectar americanus → Hookworm Larvae penetrate skin of feet, or faecal-oral route Cutaneous larva migrans (Ancylostoma braziliense or caninum) Larvae penetrate skin of feet (esp in sandy soil) Strongyloides stercoralis → Strongyloidiasis ●​ Larvae penetrate skin of feet, or faecal-oral route ●​ Autoinfection (larvae penetrate large intestinal mucosa and migrate to other organs) S/smx ± Ix Mx ●​ Pulmonary: Loeffler’s syndrome ●​ GI: malnutrition, malabsorption, obstruction ●​ Biliary obstruction -bendazoles Iron deficiency anaemia, bloody diarrhoea, chronic colitis with growth retardation, rectal prolapse -bendazoles ●​ Skin rash (“round itch”) papulovesicular lesions where larvae penetrate the skin (eg on soles of feet) ●​ Pulmonary: Loeffler’s syndrome ●​ Acute GI smx: NVD, abdo pain ●​ Chronic iron deficiency anaemia -bendazoles Itching and vesicle formation → characteristic serpiginous rash ●​ Skin rash (“ground itch”) ●​ Larvae currens - pruritic, linear, urticarial rash ●​ Pulmonary: Loeffler’s syndrome ●​ Acute GI smx: NVD, abdo pain ●​ Hyperinfection syndrome (pts present very sickly)​ Ivermectin or albendazole Ivermectin or -bendazoles Enterobius vermicularis → Pinworm / threadworm Hand-to-hand, clothing,bedding(often spreads within family or institutions) ●​ Perianal itching (esp at night);girls -± vulval itch ●​ Ix: plastic tape applied to perineal area, sent to lab to observe under microscopy ! Check all family members and tx accordingly Mebendazole 100mg stat, repeat at 2w Trichinella spiralis → Trichinosis Consumption of undercooked meat, eg raw pork Heavy infxns can cause fever, periorbital oedema, myositis -bendazoles Dracunculus medinesis → Dracunculiasis Contaminated water containing small crustaceans Worm reaches skin surface → stinging papule over lower leg → general smx (eg urticaria, NVD) → lesion vesiculates and ruptures → painful discharging ulcer Manual removal of worm. Tx 2ndary bacterial infxns. Onchocerca volvulus → Onchocerciasis (river blindness) Female blackflies ●​ Subcutaneous nodules (onchocercomata) ●​ Onchocercal skin disease - itching, maculopapular rash + hyperpigmented skin ●​ Ocular onchocerciasis [ → 05.05] Ivermectin Wuchereria bancrofti Female mosquito → Lymphatic filariasis ●​ Adenolymphangitis: inflamed LN + surrounding lymphangitis ●​ Dermatolymphangioadenitis: cellulitis-type picture, a/w lymphangitis and oedema ●​ Chronic - Lymphedema ± Diethylcarbamazin e progression to elephantitis Loa loa Deer fly, horse fly ●​ Calabar swellings - red itchy swellings below skin ●​ Ocular smx - adult worms can migrate and crawl beneath conjunctiva (which can be seen!!)​ Diethylcarbamazin e Toxocara canis → Toxocariasis Ingestion of infective eggs ●​ Visceral larva migraines: hepatitis, pneumonitis ●​ Ocular larva migrans: uniocular visual impairment, granuloma formation​ Diethylcarbamazin e Echinococcus granulosus → Hydatid disease Ingestion of eggs in dog faeces. Intermediate hosts include sheep, cattle ( farmers more affected) ●​ Cysts - liver (50-70%), lungs(20-30%), buy any any organ can be affected (incl heart, bones, CNS) - can be asmx & incidental findings ●​ Can cause anaphylaxis if cysts rupture​ Asmx: observe Smx: surgical resection & bendazoles Taenia solium Undercooked pork ●​ Cysticercosis (cysts in various organs) - tends to be asmx, incidentally discovered ●​ Neurocysticercosis - mass lesions in brain with swiss cheese appearance -bendazoles Schistosoma spp → Schistosomiasis Hosted by snails - release cercariae that penetrate skin ●​ Swimmer’s itch - itchy papular rash ●​ Acute schistosomiasis (Katayama fever): 4-8w after infxn; flu-like smx + hepatosplenomegaly, lymphadenopathy ●​ Chronic granulomatous infection, fibrosis of urinary tract (S. haematobium) or portal venous system (S. mansoni or japonicum) ●​ ! S. haematobium risk factor for bladder cancer Praziquantel Paragonimus westermani Undercooked crustaceans (eg crayfish, crabs) Predisposes to secondary bacterial infection of lungs Praziquantel Clonochis sinensis​ (oriental liver fluke) Undercooked fish (esp in East Asia) Usually asmx. Biliary tract inflammation ! Risk factor for cholangiocarcinoma Praziquantel Fasciola hepatica → Fascioliasis Sheep, cattle → faeces in water → completes life cycle in water snails ●​ Acute hepatic migratory phase: fever, RUQ pain, hepatomegaly ●​ Chronic biliary phase: asmx, or biliary obstruction, cirrhosis years after exposure Triclabendazole 🧑‍🌾 ​ From top… ●​ Nematodes (roundworms) ○​ Light red - intestinal ○​ Dark red - Tissue ●​ Cestodes (tapeworms) ●​ Trematodes(flukes) Note ●​ Disease with bolded borders indicates more exam-relevant topics ●​ This is not an exhaustive list of helminth disorders