Parasitology Written Questions

fffeu 1. Compare between Taenia saginata, Taenia solium ( Intermediate host, Mode of infection, infective stage). Teania solium Teania saginata Intermediate host Pig...

fffeu 1. Compare between Taenia saginata, Taenia solium ( Intermediate host, Mode of infection, infective stage). Teania solium Teania saginata Intermediate host Pig Cattle Mode of infection Ingestion of raw pork meat contain Ingestion of raw beef contain Cysticercus cellulose Cysticercus bovis Infective stage Cysticercus cellulose Cysticercus bovis 2. Give an account on cysticercosis: It is invasion of human tissue by larva stage of T. solium (cysticercus cellulosa) Mode of infection: 1. Ingestion of T. solium egg in food or drink 2. External auto infection 3. Internal auto infection 3. Mention the Definitive host, intermediate host, mode of infection and infective stage of Echinococcus granulosus Definitive host → Dog intermediate host → Sheep (accidentally man) Mode of infection and infective stage: Ingestion of food or drink contaminated with egg Playing or kissing with infective dog 1 4. Mention the infective stage, mode of infection of Hymenoiepis nana. Ingestion of H. nana egg Ingestion of food or water contaminated with egg External auto infection (hand to mouth) Internal auto infection when egg released in the intestinal hatch itself Accidental ingestion of rat flea (I.H) → cysticercoid larva 5. Enumerate 3 parasites transmitted by autoinfection, mention the habitat, infective stage of each one. 1. Enterobius vermicularis Habitat: Large intestine (colon, cecum) Infective stage : mature egg 2. Strongyloides stercoralis Habitat: Small intestine Infective stage: Filariform larva 3. Hymenolepis nana Habitat: Small intestine( illum) Infective stage : Embryonated egg 2 6. Give an account on types of females of nematodes: 1. Oviparous (lay eggs) Examples: unesgmented egg (Ascaris, Trichuris, Ancylostoma, Necator, Enterobius) 2. Ovoviviparous (lay eggs containing fully formed larvae that hatch immediately) Examples: Strongyloides 3. Viviparous ( Producing larvae) Example: Dracunculus, Trichinella, Wuchereria, Brugia 7. Enumerate 2 small intestinal nematodes, 2 large intestinal nematodes, mention the mode of infection of each one: Small Intestinal Nematodes 1. Ascaris lumbricoides Mode of infection: Ingestion of embryonated eggs, children playing in soil containing egg 2. Strongyloides stercoralis Mode of infection: Skin penetration by filariform larva Large Intestinal Nematodes 1. Trichuris trichiura Mode of infection: Ingestion of embryonated eggs 2. Enterobius vermicularis Mode of Infection: - Ingestion of eggs (by contaminated hands, food, or drink) Contact with contaminated clothes or bed sheets - External autoinfection (from anus to mouth) 3  8. Enumerate 3 parasites causing loefflers syndrome, mention the mode of infection of each one: 1. Ascaris lumbricoides Mode of infection: Ingestion of embryonated eggs, children playing in soil containing egg 2. Strongyloides stercoralis Mode of infection: Skin penetration by filariform larva 3. Ancylostoma duodenale Mode of infection: Skin penetration by filariform larvae 9. Mention 1 parasite causing the following medical conditions, mention its habitat, mode of infection: A. Intestinal obstruction: Parasite: Ascaris lumbricoides Habitat: Small intestine Mode of infection: Ingestion of embryonated eggs from contaminated food or water B. Iron deficiency anemia: Parasite: Ancylostoma duodenale (Hookworm) Habitat: Small intestine Mode of infection: Skin penetration by 3rd stage Flariform larva from contaminated soil 4 C. Pruritis ani: Parasite: Enterobius vermicularis (Pinworm) Habitat: Large intestine Mode of infection: 1. Ingestion of eggs: by Handling of contaminated linen and clothes Contaminated foods and drink 2. External autoinfection (hand to mouth) 3. Retroinfection: egg hatch perineal and larvae migrate back to anus 4. Air born by polluted eggs in dust D. Electolyte imbalance ( Decrease in sodium. Potassium and calcium): Parasite: Capillaria philippinesis Habitat: Small intestine (jejunum) Mode of infection: Ingestion of non well cooked fish containing infective larvae E. Elephantiasis: Parasite: Wuchereria bancrofti Habitat: Adult in lymphatic vesseles and nodes especially in abdominal or inguinal lymph node Mode of infection: Bite of Culex mosquito carring 3rd stage flariform larvae F. Calabar swelling: Parasite: Loa loa Habitat: Subcutaneous tissues of eye Mode of infection: Bite of Chrysops fly (deer fly) third stag larvae 5 G. River blindness: Parasite: Onchocerca volvulus Habitat: Adult in subcutenous tissue Mode of infection: Bite of blackfly (Simulium) H. Dysentery: Parasite: Entamoeba histolytica Habitat: Large intestine ( cecum) Mode of infection: ingestion of mature cyst in food , drink or from contaminated hand I. Steatorrhea: Parasite: Giardia lamblia Habitat: Small intestine (duodenum) Mode of infection: Ingestion of cysts in contaminated water or food J. Skin ulcer: Parasite: Leishmania tropica Habitat : Skin (macrophages in dermis) Mode of infection : Bite of infected sandfly (Phlebotomus) K. Kala azar: Parasite: Leishmania donovani Habitat: Reticuloendothelial system (liver, spleen, bone marrow) Mode of infection: 1. Bite of sand fly or Conjential from mother to fetus 2. Blood transfusion 6 L. Chronic sleeping sickness: Parasite: Trypanosoma brucei gambiense Habitat: Blood, lymph, and later cerebrospinal fluid (CNS) Mode of infection: Bite by infection testse fly Conjential transmission and Blood transfusion M. Hemolytic anemia: Parasite: Plasmodium falciparum (or any Plasmodium species) Habitat: Liver cell and RBC Mode of infection: 1. Bite of infected Anopheles mosquito 2. Blood transfusion 3. Congintal N. Lymphadenopathy: Parasite: Toxoplasma gondii Habitat: intracellular ( muscle , Brain) Mode of infection: 1. Ingestion of sporulated oocyte in food or water with cat feces 2. Eating uncooked meat containing ( tissue cyst, Bradyzoite) 3. Congintal toxoplasmosis ( Tachyzoite) 4. Blood transfusion ( Tackzoite) 5. Organ transplantation ( tissue cyst , Bradyzoite) 7 10. Enumerate 2 parasites transmitted by skin penetration, mention the habitat, infective stage of each one: 1. Strongyloides Stercoralis Habitat : Small intestine ( Duodenum and Jejunum) Infective stage : 3rd Stage of Flariform larvae 2. Ancylostoma Habitat : Small intestine Infective stage: 3rd stage filariform larva 11. Enumerate 2 parasites transmitted by eating undercooked pork, mention the habitat, infective stage of each one: 1. Taenia solium Habitat: jejunum of the small intestine Infective stage: Cysticercus cellulosae 2. Toxoplasma Gondii Habitat: Intestinal cells (in cats), tissue (in humans) Infective stage: Tissue cysts or oocysts. 8 12. Give an account on locomotor structures in protozoa with examples: 1. Pseudopodium: extension of ectoplasm followed by endoplasmic ( entameba histolytica trophozoite) 2. Cilia: numerous short hair- like threads covering the surface ( Balantidium coli) 3. Flagellum: long whip like structure found on cell surface ( Trypanosoma) 4. Gliding and twisting: the movement is propagated through the myonemes ( plasmodium spp) 13. Give an account on types of reproduction in protozoa with examples: A) Asexual reproduction: ① Binary fission → (Flagellates – Ciliate – Entamoeba) ② Multiple fission → Plasmodium in man ③ Budding → Toxoplasma gondii B) Sexual reproduction: ① Gametogony → Plasmodium in female Anopheles ② Conjugation → Balantidium coli 9 14. Give an account on medical importance of arthropods: They may cause a disease: 1. by adults: Transmission of allergenic or poisonous subs through their bites * Ticks and Scorpions. Invasion of skin causing cutaneous manifestations scabie mites Annoyance of domestic animals 2. By larvae: Invade different tissue of animals or man causing Myiasis *larvae of some dipterous flies They may transmit a disease: ① By inoculation of a pathogen into the bite wound * Glossina in Trypanosoma ② By contamination of bite wound with insect feces containing Pathogen winged bugs in Trypanosoma Cruzi ③ By crushing of infected arthropod on skin 10 15. Give an account on mechanical and biological transmission of diseases by arthropods with examples: Mechanical: By contamination their different parts by stool * house flies and Entamoeba histolytica cysts or passive carrier by their wet proboscis * stable flies and blood parasites Biological: Propagative organisms: multiplies with out development all arthropod-borne bacterial, rikettsial and viral disease as fleas in plague. Cyclodevelopmental:- Parasites develop without multiplication *all helminth Parasite transmitted by arthropods as mosquitos in filarial worms Cyclopropagative: the causative organism undergoes multiplication and development ( malaria) Transovarian: Parasites are transmitted to the offspring's through the eggs e.g. tick-borne diseases especially in one host tick as in babesiosis. Trans-stadial (stage to stage): Parasites transmitted from the infected larvae to nymph to adult's e.g. Dipylidium caninum 11 16. Differences between complete, incomplete metamorphosis in arthropods with examples: Complete metamorphosis (Holometabola) : Egg → Larva → Pupa → Adult larvae and pupa are completely different in morphology, habitat, feeding habits than adult.. ex. mosquitoes. Incomplete metamorphosis (Hemimetabola) Egg → Nymph → adult Nymph is similar to the adult but smaller in size, paler in color,sexually immature.. similar in feeding habits to adult ex. bugs and lice 17. Medical importance of fleas: 1. As vector of diseases: Plague: Is established in rats and transmitted to man by the rat flea, and established in man by human flea, Pulex irritans. Endemic or murine typhus:Causative organism is Rickettsia mooseri. 2. As an intermediate host of parasitic diseases: Rat fleas act as I.H. for H. nana& H. diminuta Dog and cat fleas act as I.H. for D. caninum. 3. Tunga penetrans : female pentrate skin in between the toes or fingers, and the sole of the feet (chigger or jigger disease). 12 18. Medical impotance of lice: A-Bites of adults and nymph can cause severe itching and dermatitis. Scratching increases the inflammation and may lead to secondary bacterial infection. B-Prolonged and severe infestation with body lice can cause darkening and thickening of the skin, in a condition called (vagabond's disease.) C-They are vectors of: 1) Epidemic (louse-born) typhus, caused by Rickettsia prowazekii, and mainly transmitted by Pdiculus humanus. 2) Trench fever, caused by Quintana, transmitted by the bite of the louse or by contamination of the abraded skin. 3) Relapsing fever, caused by Borrelia recurrentis. 19. Medical importance of: A. Anopheles, culex, Aedes mosquitoes Anopheles : Transmit malaria. Culex mosquitoes: Transmit "Bancroft's filariasis" and encephalitis. Aedes mosquitoes: Transmit yellow fever and Dengue fever B. Simulium Transmit Onchocerca volvulus → River blindness Painful bite → itching, fever, nausea, headache May cause Black fly fever 13 C. Sand fly Leishmaniasis caused by leishmania donovani, L.tropice ( Phlebotomous ) and L. Braziliensis ( Lutzomyia) Sand Fly fever D. Musca domestica (A) Disease transmission: House fly transmits microorganisms to our food or body directly mechanically: Bacteria: Vibrio cholera, Streptococci, Shigella, Salmonella, Escherchia coli. Protozoa: E. histolytica cysts, Giardia cysts, Balantidium cysts. Helminth eggs: As Taenia, Ascaris, Trichuris, Oxyuris, and Hymenolepis nana. (B) Disease causation: Larvae of flies may cause myiasis E. Glossina palpalis, Glossina morsitans G. palpalis is the vector of Gambian (chronic) sleeping sickness. G. morsitans is the vector of Rhodesian (acute) sleeping sickness 20. Medical importance of Cyclops: It acts as an intermediate host for: 1. Diphyllobothrium latum. 2. Diphyllobothrium mansoni. 3. Dracanculus medinensi 14 21. Enumerate 3 parasite transmitted by blood transfusion: Leishmani donovina Toxoplasm Trypanosoma cruzi T. Gambiense T. Rhodesiense Plamodium vivax P. Malaria P. Ovale P. Falciparum 15