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57 Cards in this Set
- Front
- Back
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What organisms can cause elephantiasis?
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Wuchereria bancrofti, brugia malayi, B timori
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Why is doxycycline effective in treating elephantiasis?
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responsible organisms have a population of symbiotic bacteria (Wolbachia) that live inside the worm (when bacteria is killed, so is the worm)
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What is Wolbachia?
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bacteria that lives inside organisms that cause elephantiasis: 8 week course of tetracyclines complete eliminate microfilariaemia
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What organisms are nematodies/roundworms?
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Enterobius vermicularis (pinworm), trichuris trichiura (whipworm), ascaris lumbricoides (ascariasis), hookworms, strongyloides stercoralis
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How is E vermicularis/pinworm transmitted? How does it cause disease?
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oral-fecal contamination: larvae hatch in sm intestine and move into lg intestine where they mature, mate near cecum--> gravid females migrate to perianal area to deposit eggs
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What are the symptoms of E vermicularis infection?
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severe pruritis, secondary bacterial infection, sleep loss, fatigue, worms can migrate to the vagina and cause granuloma, worms can rarely penetrate the bowel wall and migrate to the peritoneum, liver, and lungs
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What organism can cause severe pruritis, secondary bacterial infection, sleep loss, fatigue, worms can migrate to the vagina and cause granuloma, worms can rarely penetrate the bowel wall and migrate to the peritoneum, liver, and lungs?
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E vermicularis: pinworm
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How is E vermicularis/pinworm treated?
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many drugs effective: Vermox, reinfecitno is common
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What is trichuris trichiura/whipworm? What are the symptoms?
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whip-shaped nematode 50-50 m in length; light infections: asymptomatic; heavy infections: abdominal pain/distension with bloody/mucoid diarrhea, appendicitis, prolapsed edematous rectum, chronic dysentery, severe anemia, growth retardation in children with more than ~200 worms
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Heavy infection of what organism can cause abdominal pain/distension with bloody/mucoid diarrhea, appendicitis, prolapsed edematous rectum, and chronic dysentery, severe anemia, growth retardation in children with more than ~200 worms?
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trichuris trichiura/whipworm
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The life cycles of E vermicularis (pinworm) and trichuris trichiura (whipworm) have similar lifecycles. Which one requires 203 weeks development in the soil to become infectious?
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trichuris trichiura/whipworm
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What is ascaris lumbricoides? How does it cause disease?
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one of the largest nematodes (30 cm), soil-transmitted: 2-3 weeks in soil to become infective; swallowed--> hatch in duodenum--> penerate wall--> enter blood or lymphatic vessels--> carried to liver and heart--> pulmonary ceirculation--> break out of capillaires into alveoli--> grow/molt--> migrate through airways--> coughed up and swallowed--> return to intestine--> lay eggs
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What are the symptoms of Ascariasis?
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pneumonitis, asthma attacks in non-asthmatics; intesntinal obstruciton from heavy infection, and occasionally may migrate to the bile ducts, pancreas, gallbladder, or liver
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What helminth causes pneumonitis, asthma attacks in non-asthmatics; intesntinal obstruciton from heavy infection, and occasionally may migrate to the bile ducts, pancreas, gallbladder, or liver?
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ascaris lumbricoides
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What 2 organisms are common hookworms?
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ancylostoma duodenale, necator americanus
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How do hookworms (Ancylostoma duodenale, Necator americanus) cause disease?
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eggs--> rhabditiform larvae --> larvae molt twice--> filariform larvae--> penetrate skin--> circulation--> lungs--> migrate to trachea and are swallowed--> small intestine: attach, suck blood and tissue fluid and mate--> lay eggs
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What are the symptoms of hookworm (A duodenal, N americanus) infection?
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usually asymptomatic unless worm burden is high and patient diet is deficient in Fe, protein or both--> Fe deficiency anemia
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What helminth usually asymptomatic unless worm burden is high and patient diet is deficient in Fe, protein or both--> Fe deficiency anemia?
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hookworm (A duodenale, N americanus)
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How is hookworm (A duodenal, N americanus) treated?
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mebendazole
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What is the life cycle of Strongyloides similar to? How is it different?
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hookworm; eggs hatch in intestinal mucosa and rhabditiform larvae are passed in the feces
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How does autoinfection of S stercoalis occur? What is the result?
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transformation of rhabditiform filariform larvae in the gut followed by penetration in circulation; routes other than the lungs occur, which can lead to massive and often fatal dissemination
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How can disseminated infection occur with strongyloids stercoralis?
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autoinfection
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What helminths penetrate the skin?
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hookworm, strongyloides
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What are the features of disease caused by S steracoralis?
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AIDS: dyspnea, abdominal pain (invasion of lungs, liver, brain), gram negative sepsis unless recognized; dissemination from upper bowel can occur years after acquisition
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Who is more likely to suffer from autoinfeciton and disseminated disease from strongyloides?
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immunosuppressed (especially with high dose corticosteroids or AIDS)
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What helminth can cause vomiting, diarrhea, and anemia and is more likely to have autoinfection and dissemination in patients with AIDS?
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strongyloides steracolis
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What helminths are cestodes/tapeworms?
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hymenolepis nana (dwarf tapeworm), taenia saginata (Beef tapeworm), taenia solium (pork tapeworm), diphyllobothrium latum (fish tapeworm), echinococcus granulosus
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Describe the structure of tapeworms/cestodes?
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anterior attachment organ (scolex) and a stroblia (chain of proglottids)
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What is hymenolepis nana (dwarf tapeworm)? How is it acquired? What are the symptoms?
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cestode: dwarf tapeworm; no intermediate host; acquired through egg ingestion;large infection: abdominal pain, diarrhea, headache, anorexia, etc
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What are taenia saginata and taenia solium? How are they acquired? What is the definitive host?
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beef/port tapeworm; human eats undecooked meat--> scolex attaches to the intestinal wall and creates a chain of proglottids (human = definitive host)
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Can taenia saginata (beef tapeworm) or taenia solium (pork tapeworm) cause cystercercosis (human = secondary host)? What does this cause?
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pork, not beef; penetrate wall and carried to any part of body (most frequently muscle, but cerebral and neurocysticercosis)
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What are the symptoms associated with primary infeciton of T solium or T saginata? Cystercercosis?
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primary: often asymptomatic; cystercercosis: many asymptomatic, cerebral edema, granuloma, hydrocephalus, epilepsy, stroke, etc)
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Why is it important to treat pork tapeworm with anti-helminths?
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infected person can transmit it via fecal-oral contact; possibility of development of cysticerci (especially in brain)
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Can beef tapeworm be transmitted between humans? Why?
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no: intermediate host required (not infectious to humans)
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How many intermediate hosts are required for diphyllobothrium latum (fish tapeworm)?
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2: copepods (small crustaceans), fish
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How is diphyllobothrium latum acquired? What are the symptoms?
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consumption of raw fish; usually asymptomatic, B12 deficiency (indistinguishabel from perinicious anemai can occur in proximal jejunum
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What is sparganosis? How is it acquired?
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tapeworm of dogs, felines, some reptiles; consumption of copepods in water or meat from listed animas--> worm encysts most frequently in CNS/breast tissue
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What is anisakiasis? How is transmitted?
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worm of marine mammals-->nausea, vomiting, can have chronic fever and abdominal pain
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What is echinococcus granulosus? How does it cause disease?
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hydatid cyst: ingest eggs from feces of carnivores--> eggs hatch in intestine--> larvae migrate to many sites-->form slow-growing, tumor-like hydatid cysts
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What organism forms slow-growing, tumor-like hydatid cysts?
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Echinococcus granulosus (hydatid cyst)
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What are the symptoms of Echinococcus granulosus?
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similar to slow growing tumor: inflammatory reaction in surrounding tissue
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How is echinococcus granulosus treated?
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surgical removal of cyst + anti-helminths
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What organisms are tissue helminths?
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trichinella spiralis (trichinosis), dracunculiasis (guinea worm), wuchereria bancrofti (elephantiasis), loa loa (loaiasis), onchocerca volvulus (onchocerciasis)
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How is trichinella spiralis (trichinosis) acquired?
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uncooked pork products, consumption of bear meat, walrus meat
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What symptoms are assocaited with trichinosis?
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larvae in heart, skeletal muscle, brain --> myalgia, headache, malaise, fever, periorbital edema, marked eosinophilia
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What is characterized by myalgia, headache, malaise, fever, periorbital edema, and marked eosinophilia?
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trichenosis
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How is dracunculiasis (guinea worm) acquired? What does it cause?
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drinking copepod infested water--> larvae develop in intestine--> migrate through subcutaneous tissue--> ulcer, migrate out through skin
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What is the most common cause of lymphatic filariasis? How is it transferred?
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Wuchereria bancrofti, mosquito transmission
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What are the characteristics of elephantiasis?
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grotesque swollen limbs and scrotum
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What is loaiasis?
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filarial disease transmitted by the horse fly (mainly in W/central africa): develops into an adult worm that migrates through connective tissue and emerges through the subconjunctival region of the eye
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What filarial disease transmitted by the horse fly (mainly in W/central africa) and develops into an adult worm that migrates through connective tissue and emerges through the subconjunctival region of the eye?
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loa loa: loaiasis
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What does onchocerca volvulus cause? How is it transmitted?
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river blindness (primarily in Africa); transmitted by the black fly
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What causes river blindness? What is it characterized by?
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onchocerca volvulus, formation of subcutaneous nodules; immediate hypersensitivity reaction to dead or dying organisms that produce itching, blindness can result from effects in the eye
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What are the 3 main syndromes assocaited with schistosomiasis?
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dermatitis: swimmer's itch, katayama fever, chronic fibro-obstructive sequelae
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What are different schistosoma species?
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S japonicum (gut), S haematobium (bladder)
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What symptoms are associated with S mansoni or S japonicum?
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no specific symptoms; extensive involvement of the liver by granulomatous reaction to embolized eggs--> hepatosplenomegaly
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What is seen with urinary schistosomiasis?
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hematuria with/without dysuria
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