Parasite PDF

# Parasite - **Carrier:** A person who has no clinical symptoms, important source of infections in epidemiology. - **Definitive:** Final host adult or sexually reproductive stage of parasite. - **Intermediate host:** Larval or asexual reproductive stage. - **Reservoir hosts:** Same species of paras...

# Parasite - **Carrier:** A person who has no clinical symptoms, important source of infections in epidemiology. - **Definitive:** Final host adult or sexually reproductive stage of parasite. - **Intermediate host:** Larval or asexual reproductive stage. - **Reservoir hosts:** Same species of parasite at the same stage. - **Zoonosis:** Refers to animal disease which can be transmitted to humans. - **Vector:** Living carrier transport pathogenic organisms from infected to non-infected person. ## Types of Parasite Transmission: - **1-Mechanical:** Just transport. - **2-Biological:** Transport and reproduction. - **Paratenic host:** Abnormal host; parasites can live but can't develop. ## Helminthes according to transmission method: - **1-Soil transmitted:** Ascaris, hook worm. - **2-Snail t. H.:** Trematodae (schitiosoma). - **3-Arthropod t. H.:** Filaria, Dracanculus medianesis. - **4-Food and meat:** Taenia Saginata Taenia Solium. - **5-Direct:** Enterobins vermicularis. - **6-Sexual transmitted parasite:** Tricomonas vaginalis. # Cestoda - **Cyclophyllidea:** Taenia spp., Echinococcus. - **Pseudophyllidea:** Diphyllobothrium latum. ## General characteristics of Cestoda: - **The body consists of:** Scolex, neck, strobila. - **Flat segmented various length.** ## Scolex: - **Anterior attachment organ including 3 parts:** Sucker, rostellum, hooklets. ## Neck Region: - Contain stem cells responsible for giving rise to the strobila ## Strobila: - Chain of the segments, consist of 3 parts: - Immature - Mature, - Gravid ## Different tract of Cestoda: - **Digestive system:** No gut no mouth, absorb nutrients directly from gut of host. - **Lacks circulatory system and respiratory system.** - **All tapeworm are hermaphroditic (male and female organs found in one worm).** ## Pseudophyllidean pattern: - **1-Coracidia:** Leave the host with feces to water. - **2-Ingested by first intermediate host:** Develops in the host into procercoid. - **3-First intermidate host ingested by second intermidate host:** Develops into Pleroccoid. - **4-The pleroceroid is infective to the definitive host.** ## Cyclophyllidean pattern: - **1-Oncosphere:** Lacks ciliated and must remain in water; if digested by host. - **2-After digestion hatches in the digestive tract:** Enters the hemocoel where it metamorphoses into cysticercoid. - **3-Surrounded by several layers.** ## Taxonomy: - **1-Diphyllobothrium latum:** - 10-20m - Scolex: Elongated, almondshape, 2 bothria - Multiple testes - Bilobed ovary - Rosette-shaped uterus. - Vitelline glands ## Causal agent: - Intestinal warm (Lishor broud tape worm). - The largest tape worm in human small intestine. ## Clinical features: - Long lasting infection (decades). - Abdominal discomfort, diarrhea, vomiting, and weight loss. - Vitamin B12 deficiency with pernicious anemia may occur - Massive infections: Intestinal obstruction, appendicitis - Can cause cholecytitis, or cholangitis. ## Laboratory diagnosis: - Microscopic of eggs in stool. - Proglottids in feces. - Megalo blastic Macrocytic anemia. ## Treatment: - **Praziquantel:** 25 mg/mg effective agains D. Latum - **Lower dose 10 mg/kg effective against other species** - **Niclosamide:** Single 2 gram dose for adult or 1 gram dose for children. - **Praziquantel:** Can be given in pregnancy. - Paromomycin, quinia crine Hcl and amino crine, Enema, Vitamin B12. ## Diagnostic findings: - **Microscopy:** - 30x60 microns - Carmine stained proglottids shows the rosette shape uterus. ## Spiro metra (Tissine extra intestinal cestoda in human) - **D. imansonoides - D. mansoni** - **Sparganosis:** Infection with plerocercoid larvae. - **Proliferative sparganosis or nonproliferative sparganosis:** Name of the disease. ## Human infected, can in one of three ways: - **1-Ingestion of cyclops containing larvae in drinking water.** - **2-By application of flesh of an infected frog to ulcers** - **3-By ingestion of raw or undercooked meat of infected frogs, sneaks, mammals or birds** ## Diagnosis of sparganosis: - **History:** Eating habit. - **Clinical sign:** Nodules. - **CBC:** Eosinophillia ## Treatment: - **Surgical remove.** - **Praziquantel, Niclosamide, mebendazole**