Term
| What round worm usually is asymptomatic but with eosinophilia, and can cause abdominal pain and diarrhea? |
|
Definition
| Strongyloides stercoralis |
|
|
Term
| How does Strongyloides stercoralis maintain chronic infection? |
|
Definition
|
|
Term
| How does autoinfection occur? |
|
Definition
| Rabditiform larvae in large intestines become filariform larvae, penetrate intestinal mucosa or perianal skin, enter circulation system, transport to lungs, penetrate alveolar space, carried to trachea and swallowed, become adults in intestines, deposit eggs, starts over. |
|
|
Term
| How do Strongyloides initially infect? |
|
Definition
| penetrate the intact skin |
|
|
Term
| What happens to an individual who becomes immunocompromised and was previously infected (maybe 40 years earlier) by Strongyloides? |
|
Definition
Hyperinfection Syndrome
Acute abdomen, Respiratory Distress, GNR sepsis
Blood eosinophilia my be absent |
|
|
Term
| When is serology useful for diagnosing Strongyloides stercoralis? |
|
Definition
| Useful for Chronic Form to check for eosinophilia |
|
|
Term
| How can Strongyloides be diagnosed? |
|
Definition
Larvae in stool or sputum
Serology |
|
|
Term
| What is the treatment for Strongyloides stercoralis? |
|
Definition
|
|
Term
| What symptoms are associated with the 3 stages of infection by Strongyloides? |
|
Definition
Skin Invasion -> purpuric papule
Lung Migration -> Loeffler's syndrome
Intestinal phase -> GI symptoms |
|
|
Term
| What species of Hookworm is associated with the Americas, Africa, Southern Asia, and Australia? |
|
Definition
|
|
Term
| What hookworm is found in the Mediterranean and northern Asia? |
|
Definition
|
|
Term
| How do hook worms stay in the intestines? |
|
Definition
grasp intestinal villi with teeth or cutting plates
Eat tissue |
|
|
Term
| How can hook worms cause anemia? |
|
Definition
| Eat intestinal tissue, produce anticoagulant, facilitates bleeding |
|
|
Term
| What can the larva stage of hookworms do? |
|
Definition
| Migratory, can produce inflammation and eosinophilia |
|
|
Term
| How are hookworms treated? |
|
Definition
|
|
Term
| What is the life cycle of roundworms from visceral larva migrans? |
|
Definition
Eggs from dog or cat roundworm ingested -> Larva penetrate mucosa, enter circulation, carried to liver, lungs, eyes -> cause inflammatory necrosis
Do Not Replicate |
|
|
Term
| At what point are Ascaris lumbricoides infectious? |
|
Definition
| When embryos develop in fertilized eggs, under suitable environmental conditions |
|
|
Term
| What is the life cycle of Ascaris lumbricoides? |
|
Definition
| Infective eggs ingested and hatch in small intestines -> enter venules or lymphatics -> pass through heart and lung to alveoli -> migrate up bronchi -> trachea -> swallowed -> mature to adults in small intestines -> produce eggs -> eggs excreted in feces |
|
|
Term
| How long do Ascaris Lumbricoids live and how many eggs can they produce? |
|
Definition
Live 1-2 years
Produces 200,000 eggs per day |
|
|
Term
| How big can Ascaris Lumbricoides get in the intestines? |
|
Definition
|
|
Term
| Why don't you treat Ascaris lumbricoides in the acute infectious stage? |
|
Definition
| If worms are in the lungs and die they will cause inflammation and respiratory distress |
|
|
Term
| How is Ascaris Lumbricoides prevented and treated? |
|
Definition
Good Hygiene, proper disposal of sewage
Pyrantel pamoate (1 dose)
mebendazole (3 doses) |
|
|
Term
| Why are you likely to see hookworms if a person is infected with Ascaris? |
|
Definition
| infect the same way, improper disposal of sewage |
|
|
Term
| What worm is associated with the consumption of undercooked pork? |
|
Definition
|
|
Term
| What is the life cycle of T. spiralis? |
|
Definition
| Ingestion of encysted larva in muscle of undercooked pork -> Larva released in small intestines -> Adults grow in small intestines -> larva deposited in mucosa -> circulation -> form cysts in striated muscle |
|
|
Term
| What worm initially causes gastroenteritis, followed by fever, muscle tenderness, inflammation and weakness? (increased WBC and eosinophilia) |
|
Definition
|
|
Term
| After infection with T. spiralis when will a patient show eosinophilia and positive serology? |
|
Definition
|
|
Term
| How is Trichinella spiralis prevented and treated? |
|
Definition
Supportive therapy for inflammation
Mebendazole eliminates adults, not larvae
Prevent by eliminateing parsite in hogs, adequately cook meat |
|
|
Term
| What metazoan parasite is transported to humans by mosquitos? |
|
Definition
Bancroftian filariasis
(Elephantitis) |
|
|
Term
| How does bancroftian filariasis go from the diagnostic stage (microfilariae) to the infective stage (L3 Larvae)? |
|
Definition
| Mosquito takes blood from infected human, ingests microfilariae -> microfilariae shed sheaths, penetrate mosquito's midgut, migrate to thoracic muscles -> L1 larvae -> L3 larvae -> migrates to mosquito's head and proboscis |
|
|
Term
| How does Wuchereria bancrofti block lymphatic channels? |
|
Definition
| adults develope and reproduce in lymphatics causing inflammation -> die after about 5 years -> calcify, create more inflammation -> blocks lymphatics -> Fluid accummulates distally |
|
|
Term
| Why is Wuchereria bancrofti diagnosed by taking blood at night? |
|
Definition
Microfilaria migration only at night
(aggregate in lung capillaries during the day) |
|
|
Term
| How is Lymphatic filariasis (elephantiasis) treated? |
|
Definition
Diethylcarbamazine kills adults
Steroids Reduce inflammation |
|
|
Term
| Where do the eggs of the pinworm mature? |
|
Definition
|
|
Term
| Where do female pinworms migrate to at night to lay eggs? |
|
Definition
|
|
Term
| Where do pinworms hatch and grow? |
|
Definition
|
|
Term
| What worm is the most common helminth infection in the US? |
|
Definition
Pinworm infection
(Enterobius vermicularis) |
|
|
Term
| What worm should be suspected with perianal irritation? |
|
Definition
Pinworm
(Enterobius vermicularis) |
|
|
Term
| What test can be preformed to check for pinworm infections? |
|
Definition
|
|
Term
| How are Pinworm infections treated? |
|
Definition
2 Doses pyrental pamoate, 2 weeks apart
Treat whole family
Sanitize Bedclothes
Cut kids nails short |
|
|
Term
| What species of Schistosomiasis can cause periportal fibrosis and portal hypertension with hepatosplenomegaly? |
|
Definition
|
|
Term
| What species of Schistosomiasis can cause bladder granulomas, hematuria, and is associated with bladder cancer? |
|
Definition
|
|
Term
| Once Schistosomiasis is excreted as the diagnostic stage, how does it develope into the infective stage? |
|
Definition
| Eggs hatch in water releasing miracidia -> penetrate snails -> Sporocysts in snails -> Cercariae released by snail -> free swimming in water -> Penetrate skin of host |
|
|
Term
| After Cercariae penetrate skin of the host, how does schistosomiasis develop? |
|
Definition
| Cercariae lose tail become schistosomulae (coats self in host proteins) -> circulation -> portal blood in liver and mature into adults -> Paired adults migrate to mesenteric venules of bowel -> lay eggs -> excreted in urine and feces |
|
|
Term
| How can Schistosomiasis cause acsites? |
|
Definition
| Some eggs don't get excreted and go back into venous system causeing portal hypertension -> ascites |
|
|
Term
| How is Schistosomiasis (blood fluke) treated? |
|
Definition
praziquantel
snail control
proper sewage disposal |
|
|
Term
| What species of schistosomiasis is found in Africa? |
|
Definition
|
|
Term
| What species of schistosomiasis is found in Asia? |
|
Definition
|
|
Term
| What species of schistosomiasis is found in America? |
|
Definition
S. mansoni
But has been irradicated from the snail population.
(There is a species that replicates in ducks and can cause pruritic lesions but does not replicate in humans) |
|
|
Term
| What is the life cycle of the Tape worms? |
|
Definition
| Cattle or Pigs become infected by ingesting vegetation contaminated by eggs -> Onoospheres hatch, penetrate intestinal walls, circulate to musculature -> develope inot cysticorei in muscles -> humans infected by ingesting undercooked meat -> Scolex attaches to intestine -> Adults grow in small intestine, reproduce |
|
|
Term
| What species of Tapeworm can develop cysticercosis? |
|
Definition
|
|
Term
| How is T. saginata and T. solium treated and prevented? |
|
Definition
Praziquantel
Try to find expulsed scolex to be sure
Prevention through beef and pork inspection
adequate cooking or freezing kill cysticeri |
|
|
Term
| What worm can cause Neurocysticerosis? |
|
Definition
|
|
Term
| What part of the tapeworms break off and are released along with numerous eggs? |
|
Definition
|
|
Term
| What does the tapeworm look like? |
|
Definition
up to 10 meters long
composed of:
Scolex - head with sucking parts
Proglottids - segments of branched uteri that produce thousands of eggs |
|
|
Term
| What stage of T. solium can produce cysts in various tissues causeing symptomatic disease? |
|
Definition
|
|
Term
| What Tapeworm is the smallest? |
|
Definition
|
|
Term
| What type of worm forms cysts in many tissues that grows slowly over time? |
|
Definition
|
|
Term
| What can happen if a cyst formed by Echinococcus ruptures? |
|
Definition
| anaphylaxis, immediate cytokine storm |
|
|
Term
| Where are animal are adult Echinococcus present? |
|
Definition
GI tract of dogs
(sheep herding dogs) |
|
|
Term
| How are dogs infected with Echinococcus? |
|
Definition
| by ingesting infected sheep |
|
|
Term
| What animal is the intermediate host of Echinococcus? Definitive Host? |
|
Definition
Intermediate - sheep, goats, swine
Definitive - Dogs, other carnivores |
|
|
Term
| What organism multiplies by binary fission in the female genital tract and is transmitted by sexual contact? |
|
Definition
|
|
Term
| What form is T. Vaginalis in vaginal and prostatic secretions and urine? |
|
Definition
|
|
Term
| At what point is T. Vaginalis in its diagnostic stage? |
|
Definition
| Trophozoite in vaginal and prostatic secretions and urine |
|
|
Term
| When is is T. Vabinalis in the infective stage? |
|
Definition
| when the Trophozoite is in the vagina or orifice of urethra |
|
|
Term
| What protozoan is a trophozoite, a single nucleus, undulating membrane, symetrical axostyle, with 4 flagella? |
|
Definition
|
|
Term
| What protozoa produces a pH >4.5 with copious, frothy discharge in women? |
|
Definition
Trichomonas vaginalis
(asymptomatic in men) |
|
|
Term
| What protozoa causes vaginal epithelium and "strawberry cervix"? |
|
Definition
|
|
Term
| How is Trichomonas vaginalis Diagnosed and treated? |
|
Definition
Trophozoites in discharge - PCR
Metronidazole
(Safe Sex Practices-prophylactic) |
|
|
Term
| What type of protozoa can cause extra-intestinal abscesses containing "anchoby paste" aspirate? |
|
Definition
|
|
Term
| What is the life cycle of E. histolytica? |
|
Definition
| Mature cysts ingested -> Excystation in sm intestine -> trophozoites migrate to Lg intestine -> produce cysts -> pass in feces |
|
|
Term
| What 3 types of disease can E. histolytica cause? |
|
Definition
Asymptomatic infection
Intestinal Disease
Extra-intestinal abscesses |
|
|
Term
| What protozoa is a trophozoite in its active form that has a single nucleus, often contains ingested RBCs? |
|
Definition
|
|
Term
| What protozoa is a major cause of amebic dysentary? |
|
Definition
|
|
Term
| What are the signs and symptoms of the acute and chronic infections of Entameba histolytica? |
|
Definition
Acute - dysentery with abdominal pain
Chronic - recurrent episodes with blood and mucus in feces -> can disseminate to liver, lung, brain - form abscesses |
|
|
Term
| What protozoa causes flask-shaped ulcers in the large intestines? |
|
Definition
|
|
Term
| What is the treatment for E. histolytica symptomatic and asymptomatic? |
|
Definition
symptomatic - metronidazole
asymptomatic & eradication - iodoquinol |
|
|
Term
| What part of the intestines do E. histolytica preferentially adhere to? |
|
Definition
| elevated interglandular epithelium |
|
|
Term
| What is the recommended treatment for Primary Amebic Meningoencephalitis? |
|
Definition
|
|
Term
| What protozoa can cause PAM? |
|
Definition
|
|
Term
| How is Naegleria fowleri ingested? |
|
Definition
| through olfactory neuroepithelium |
|
|
Term
| What forms of Naegleria fowleri are found in the CSF and Tissues? |
|
Definition
Trophozoites -> CSF and Tissues
Flagellated forms -> CSF |
|
|
Term
| How does Acanthamoeba and Balamuthia mandrillaris enter the body? |
|
Definition
| Lower respiratory tract or ulcerate or broken skin |
|
|
Term
| What can Acanthamoeba and Balamuthia mandrillaris cause in immune compromised individuals? |
|
Definition
| Granulomatous amebic encephalitis |
|
|
Term
| How do Acanthamoeba eye infections start? |
|
Definition
| improper lens handling and poor hygiene |
|
|
Term
| What protazoa should be suspected in chronic keratitis that does not respond to treatment? |
|
Definition
|
|
Term
| Why is treatment of Acanthamoeba Keratitis difficult to treat? |
|
Definition
| organism's ability to encyst with the use of topical medications |
|
|
Term
| What is the life cycle of Giardia intestinalis? |
|
Definition
| ingest cysts in contaminated water/food -> Trophozoites multiply by binary fission in small bowel -> Encystation occurs as moves toward colon -> excreted in feces |
|
|
Term
| What is the most common protozoan intestinal disease in US? |
|
Definition
|
|
Term
| What protozoa is a Trophozoite with 2 nuclei, bilaterl symmetry of axostyles and suction discs, and flagella? |
|
Definition
|
|
Term
| What protozoa can cause uncontrolled flatulence, abdominal distension, foul-smelling, bulky diarrhea, but rarely with blood or necrotic tissue? |
|
Definition
|
|
Term
| What can Giardia do that may lead to malabsorption of nutrients? |
|
Definition
| Trophozoites cover and flatten intestinal epithelium |
|
|
Term
| What does increased incidence of Giardia infection in immunocompromised suggest? |
|
Definition
|
|
Term
| What is the Treatment for Giardia? |
|
Definition
|
|
Term
| What protozoa outbreaks are associated with water parks, swimming pools, and reservoir sources? |
|
Definition
|
|
Term
| What protozoa is ingested as an oocyst, releases sporozoites, differentiate into male or female merozoites, then fuse to form a zygote? |
|
Definition
|
|
Term
| Where do Cryptosporidium hominis sporozoites infect? |
|
Definition
|
|
Term
| What occurs within the walled zygote of cryptosporidium hominis that results in oocysts containing sporozoites? |
|
Definition
|
|
Term
| What protozoa is associated with community acquired diarrheal disease? |
|
Definition
|
|
Term
| How is community acquired diarrheal disease treated? (Cryptosporidium hominis) |
|
Definition
|
|
Term
| How is community acquired diarrheal disease treated? (Cryptosporidium hominis) |
|
Definition
|
|
Term
| What protozoa infects humans by the Tsetse fly? |
|
Definition
Trypanosoma brucei
(sleeping sickness - African Trypanosomiasis) |
|
|
Term
| Once the metacyclic trypomastigotes is injected into the blood stream, what is the cycle of T. brucei in the human? |
|
Definition
| transforms into trypomastigotes in blood -> carried to other sites -> multiply by binary fission in body fluids |
|
|
Term
| How does T. Brucei transmit to others? |
|
Definition
| Tsetse fly takes trypomastigotes from infected persons blood -> transforms into procyclic trypomastigotes in fly's gut -> multiply by binary fission -> leave flys midgut -> transform into epimastigotes -> multiply in fly salivary gland -> transform into metacyclic trypomastigotes -> infects when fly bites |
|
|
Term
| What type of T. Brucei is in West Africa? East Africa? |
|
Definition
West -> gambiense
East -> rhodesiense |
|
|
Term
| What are the symptoms of T. brucei? (sleeping sickness) |
|
Definition
Bite reaction - chancre
Parasitemia - Fever
CNS - coma and death |
|
|
Term
| Which form of T brucei progresses more rapidly? |
|
Definition
| East African - rhodesiense |
|
|
Term
| How is T. brucei treated in the blood and CNS stages? |
|
Definition
Blood Stage - pentamidine
CNS Stage - Melarsoprol |
|
|
Term
| What protozoa causes Chaga's disease? |
|
Definition
|
|
Term
| What two forms does T. cruzi take morphologically? |
|
Definition
Blood - trypomastigote
Tissue - amastigote |
|
|
Term
| Where is the primary lesion of Chaga's disease usually found? |
|
Definition
|
|
Term
| How does Chaga's disease progress? |
|
Definition
Acute stage - non-specific - fever, rash, Parasitemia and lymphocytosis
Chronic Stage - involves heart, esophagus, and colon |
|
|
Term
| What can T cruzi cause by directly damaging infected cells? |
|
Definition
| destruction to autonomic nerve ganglia -> cardiomegaly, megaesophagus, megacolon |
|
|
Term
| How does T cruzi multiply? |
|
Definition
| binary fussion in cells of infeted tissues |
|
|
Term
| How is T cruzi transmitted? |
|
Definition
|
|
Term
| Where are the Triatomine bug and Chaga's disease found? |
|
Definition
| Central and South America |
|
|
Term
| What protozoa is associated with the Sandfly? Where is it found? |
|
Definition
Leishmaniasis
Asia, India, Mediterranean, N. and Central Africa, S. and Central America |
|
|
Term
| How does Leishmaniasis progress in the human once the sandfly injects the promastigote stage into the skin? |
|
Definition
| Phagocytized by macrophages -> transform into amastigotes inside macro -> multiply in cells |
|
|
Term
| What are the symptoms of Leishmaniasis, Visceral, Mucocutaneous, and Cutaneous? |
|
Definition
Visceral - organisms multiply in phagocytes of spleen, liver, nodes. Hyperpigmented skin, Superinfection
Mucocutaneous - organisms in skin metastasize to mucoid tissue -> severe deformity
Cutaneous - ulcer develops at site of lesion |
|
|
Term
| How is Leishmaniasis treated? |
|
Definition
|
|
Term
| What protozoa are found in Feces of cats? |
|
Definition
|
|
Term
| What can infection of toxoplasma gondii cause in a fetus? |
|
Definition
| Hydrocephalus, generalized lymphadenopathy, hepatosplenomegaly |
|
|
Term
| What is the morphology of Toxoplasmosis in the definitive and intermediate hosts? |
|
Definition
Difinitive - Cat - Inracellular replication
Intermediate - Pseudocysts form |
|
|
Term
| What are the Human stages of the sporozoites that cause malaria? |
|
Definition
| invade liver -> grow by schizogony -> produce merozoites -> infect RBC -> Trophozoites replicate by schizogony -> produce merozoites -> infect new RBC -> Repeat |
|
|
Term
| What protozoa are associated with mosquito bites? |
|
Definition
| Plasmodium, vivax & ovale, malariae |
|
|
Term
| What does release of merozoites do in malaria? |
|
Definition
| overstimulates innate immunity, loss of RBCs |
|
|
Term
|
Definition
Quinine derivatives - RBC stage
Primaquine - Liver stage |
|
|
Term
| What are the symptoms of malaria? |
|
Definition
Parasitemia increases -> headache, pains, chilly sensation, fever
Fever and Chills become prominent and cyclic
Falciparum modify infected RBC -> become sticky for endothelium -> capillary blockage and cerebral malaria |
|
|
Term
| When do the paroxysm symptoms occur in the different forms of malaria? |
|
Definition
48 hrs - vivax, ovale, falciparum
72 hrs - malariae |
|
|
