Tapeworms Tegument + No Gut

©2009 Mark Tuttle PARASITES Protozoa Category Protazoan Vector Treatment Flagellated - Leshmani (Amastigote intracellularly) Sand fly Antimony/Amphotericin B kinetoplastid Trypanosoma brucei (Promastigote, extracellular) Tse tse fly Suramin/Melarsoprol Trypanosoma cruzi (Amastigote intracellularly) Rudviik bug None effective – nifamox Flagellated Giardia Trichomonas Agua Metronidazole Amebic Entameba (Psudopod) Sporozoa Toxoplasma Muscle/CNS Cat shit/Meat Sulfonamide/Pyruthamine (Intracellular, Plasmodium RBCs Anopheles mosquito Chloroquin/Primaquin for exo- sexual reprod) erythritic Cryptosporidium Enterocyte Agua, food Rehydrate / Paromycin

Tapeworms Tegument + no gut Tapeworm Host Infectious form Taenia saginata Beef Tapeworm Cyst ONLY Taenia solium Pork Tapeworm Cyst AND Eggs (dead end) DiphyllobothriumlLatum Fish Tapeworm (+water flea = 2 int hosts) Cyst ONLY Echinococcus granulosus (Hydatid Cyst) Dogs ↔ Sheep Eggs ONLY (dead end) Echinococcus multilocularis Dogs ↔ Rodents

Flukes Tegument + gut (no anus) egg  motile larvae (miracicidia)  SNAIL  cercaria (metacercaria)  adult Fluke Metacercarium Egg release site Fasicola hepaticum Water plants Bile (Liver fluke) Paragonimus westermani Crustaceans Sputum OR swallowed sputum  feces (Lug fluke) Schistosomas None! Directly mature to Only 50% of eggs make it back from site to GI. Others cercariae in water. die and cause inflammatory cysts (Ex. Summer’s clay pipstem fibrosis in liver) Schistosoma mansoni (lateral spine)

Schistosoma japoncicum Mesenteric vein Portal hypertension, cor pulmonale, esophageal varices (No spine)

Intestinal Nematodes: Direct life cycle

Nematode Pathophysiology Enterobius (Pinworm) - Migrate out of anus to lay eggs. Intense anal itching  autoinfection possible Trichuris - Release eggs into feces. Female lives in colon for 1-2 years. Releases 5000 eggs/day trichiura - High intensity infection (> 500 eggs) (Whipworm) o Anemia, bloody diarrhea, rectal prolapsed, TNF cachexia, clubbed fingers

Rootbeer barrel eggs Ascaris lumbricoides - Mesenteric v Liver Heart/lungsMoltBronchiolesepiglottisGI - Eosinophilia ↑, IgG↑ Egg - Adult worms in intestine are rarely a problem (many carriers are asymptomatic) unless they block GI (0.004% mortality) - Aberrant migration can cause problems Trichinella spiralis - Penetrate columnar epithelium, mature (30h, 4 molts) - 5 days: Larvae released  to muscle  encyst. To other tissue dies Fast life cycle Spiral larva - NO Eggs passed in feces!! - First week: nausea, vomiting, crampus, diarrhea (No eosinophilia yet) - Second week: Muscle invasion, myocarditis, CNS invasion  fits, coma etc (Eosinophilia) - Third week: Larvae begin to encyst Hookworm Ancylostoma, Necator - Heavy infections can have 1000+ worms, microcytic anemia - PENETRATE SKIN, Heart/lungsMoltBronchiolesepiglottisGI (Like Ascaris) Sushi egg -

Strongyloides - PENETRATE SKIN once rhabditiform larvae becomes filariaform larvae (molts) Rhabditiform - Similar to hookworm, but has NON-human reservoir hosts, eggs hatch within intestine larvae in feces** - Can get autoinfection! - String test

Tissue nematodes:Indirect life cycle (arthropod vectors)

Nematode Vector Pathophysiology Wuchereria bancrofti (et al) Mosquitoes - Lymphatic filariasis (Elephantiasis) Brugi Mosquitoes - Lymphatic filariasis (Elephantiasis) - Contains endosymbiont Wolbachia – Antibiotics cure this disease Onchocerca volvulus Black flies - Microfilariae in skin and eyes cause main disease - Live 1-2 years and die in skin or eyes causing inflammation - Does NOT cause direct infection of eye Dear ducts dry up  2ndary nfection.