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30 Cards in this Set
- Front
- Back
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What is a hyphus? Mycelium?
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hyphus - one long string of fungal cells that are united end-to-end
mycelium - multiple hyphae together - appears fuzzy (moldy) |
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What is the difference between dermatophytosis and tinea versicolor?
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both are cutaneous, hyphae fungal diseases
derm (ringworm, tinea) - pruritic papules/vesicles, broken hair and nails, red ring with central clearing - epidermophyton, trichophyton, microsporum tinea versicolor (pityriasis versicolor) - ypopigmented areras, pruritis, +/- scaling - malassezia furfur |
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Which fungal disease is caused by arthrospores in the soil, mainly in the Southwest US?
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coccidioimycosis - coccidioides immitis
arthrospores inhaled - transform to endospores - immunosuppressed individuals will disseminate to bones, skin, and CNS If immunocompetent - Valley Fever (desert rheumatism; san joaquin valley fever) - fever, cough, arthralgia |
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What test is used to check for cryptococcus meningitis?
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India ink stain
cryptococcus neoformans bird droppings - yeast inhaled - asymptomatic or pneumo - disseminates to CNS if immunosuppressed |
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What fungus is a v-shaped septate hyphae?
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aspergillus - monomorphic fungus : mold grow in decaying vegetation
grow in warm cavities like from TB or Wegener's or in deep recesses of the sinuses or any anomalous outpouchings of external auditory canal cause fungus balls contaminate the bronchi causing allergic bronchopulmonary aspergillosis high IgE |
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What is mucormycosis?
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mucor or rhizopus
monomorphi fungus - mold attacks patients with weak immunity - inhaled multiply in blood vessel walls - mainly of GI, lungs, and paranasal sinuses - block blood vessels - infarction and necrosis DKA, burns, leukemia most susceptible non-septate hyphae with right angled branches |
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What is the process that malaria infects humans?
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spread by mosquitoes
sporozoites are injected into blood - gain entry because they live in the saliva of mosquitoes - within 30 mins of entry, the sporozoites enter the liver and develop into MEROZOITES merozoites are only life cycle stage of malarial organisms that enter RBCs - the merozoites leave the liver and enter the RBCs where they undergo several different stages of development - eventually yields 8-24 new merozoites from 1 RBC new merozoites lyse the RBC - causing severe hemolysis and cycle continues |
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What RBC are attacked in the 4 different plasmodium species?
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vivax/ovale (+ hypnozoites) - only immature RBCs
falciparum - RBCs of all ages and at all stages. More RBC infected - occlusion of capillaries with RBC aggregates - hemorrhage and necrosis of many organs including the brain - cerebral malaria - urine is dark due to hemogloinuira malariae - only mature RBCs are infected |
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What is the only way you can diagnose pneumocystis carinii (pneumo jiroveci)?
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dx: bronchial lavage with silver stain of specimen (NOT XRAY)
in horses, sheep, rodents - transmitted by inhalation asymptomatic in most - can cause a diffuse, bilateral interstitial pneumo common in AIDS and premies spreads to liver, spleen, BM - 50% survive with treatment sudden onset fever, cough, dyspnea alveolar cysts - inflammation - frothy exudates - decreased O2 exchange - (late AIDS) disseminates to liver, spleen, lymph nodes, bone marrow |
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What protozoa is commonly passed on from cats?
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toxplasma gondii
toxo encephalitis - immunocomp; neuro signs - +multiple ring-enhancing lesions in brain congenital - MR, heart defects, chorioretinities, hepatosplenomegaly, jaundice, IC calcifications acquired from contaminated food or inhalation onto GI mucosa |
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What form of Leishmania is caused by sandflies? what does it cause?
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donovani
reservoir - dogs, foxes, rodents causes Kala-Azar and Black Sickness bite - to RES to cause Kala-Azar - if untreated, progresses to GI bleed, intermittent fever, weight loss, hyperpigmentation - black sickness 100% mortality w no treatment Tx: stibogluconate (cutaneous); amp B (mucosal/systemic) |
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What is the cause of Chagas Disease (American Trypanosomiasis)?
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Trypanosoma cruzi
Vector - reduviid bug (kissing bug) bite - facial edema - focal nodule (2 mos later) - most asymptomatic, but many there is invasion of myocytes and GI plexus - arrhythmias or CHF or toxic megacolon or mega-esophagus with achalasia tx: nifurtimax if early |
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What are the causes of East/West African sleeping sickness? Treatment?
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East - rhodesiense - tsetse vector, cattle reservoir, more severe, fatal
West - gambiense - vector tsetse fly, reservoir humans, along waterways enter skin by bite, enter blood, enter lymph nodes, enter brain Tx: suramin or pentamidine (only curative if given prior to encephalitis stage). Suramin can be used for either East or West, but is DOC for early East. Pentamidine is DOC for early West If encephalopathic stage - Melarsoprol +/- eflornithine are DOC M - DOC for late east E - DOC for late West |
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What is the cause of amebiasis?
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entamoeba histolytica
cysts have 4 nuclei, trophozoite has classic amoeba appearance infects colon cysts - divide into 8 throphozoites - cause tear drop or flask-shaped ulcers in colon (bloody diarrhea) - may enter portal vein - enter liver - cause hepatic abscess fecal oral, anal sex |
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What causes giardiasis?
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giardia lamblia
fecal oral cysts - 4 nuclei; trophozoite - 2 nuclei, 4 pairs of flagella infects SI associated with hikers/campers drinking stream water non-bloody, FOUL-smelling diarrhea (foul because of malabsorption of fat and protein due to inflammation) Dx: string test; giardia Ab or stool wet mount |
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What protozoa can be acquired by swimming in warm water in Southern US?
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naegleria fowleri
an amoeba enters nasal mucosa and passes thru cribriform plate causes purulent meningoencephalitis RAPIDLY fatal |
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What are the different helminths?
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Helminths: Nematodes (round worms), Platyhelminthes (flatworms)
Platyhelminthes (flatworms): Trematodes (flukes), Cestodes (tapeworms) Trematodes (flukes): Schistosoma (blood fluke), Paragonimus (lung fluke), Clonorchis (liver fluke) |
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Describe the host, egg features, infection route, and settling area of the flukes
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Sch. Mansoni - snail, large lateral spine, infects thru skin from water, settles in veins of colon
Sch japonicum - snail, small lateral spine, infects thru skin from water, veins of small intestine (+/- liver) Sch hematobium - snail, large terminal spine, thru skin from water, settles in veins of bladder Clonorchis sinesis - snails and fish, ingested with raw fish, settles in liver and bile ducts Paragonimus westermani - snail and crab, ingested with raw crab, settles in lung |
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What is the MOA of schistosoma?
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free swimming immature forms in water enter skin - enter blood - ener arterial circulation - enter liver - MATURE into adult flukes - migrate against portal flow to live in preferred mesenteric vessel
itching and dermatitis at entry site - fever, chills, diarrhea, lymphadenopathy, hepatoslplenomegaly, eosinophila - period free of symptoms - bleeding and portal HTN (mansoni/japonicum) or bladder fibrosis (hematobium) |
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What is the MOA of clonorchis?
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ingestion of contaminated fish - cysts excyst in small intestine - swim retrograde up bile ducts - MATURE to adults - mate - eggs go out with stool
leads to cholangitis - chronic infection can lead to cholangiocarcinoma |
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what is the MOA of paragonimus?
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ingestion of contaminated crab - cyst excyst in small intestine - penetrate intestine wall - migrate to and THRU diaphragm - enter lung - MATURE - mate - eggs enter bronchi - eggs coughed up or swallowed/defecated
yields chronic cough with bloody sputum - dyspnea, pleuritic chest pain - recurrent secondary bacterial pneumo (mimics TB) |
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Which stage of Taenia Solium is worse/
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immature forms that are ingested in eggs via fecal oral transmission
eggs hatch and immature forms penetrate intestine wall and migrate settle in brain, eyes and develop into cysticerci headache, vomiting, focal neuro deficits, seizures, uveitis, retinitis - CYSTICERCOSIS - death |
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What are the 3 outcomes for taenia saginata (beef worm)?
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humans eat undercooked beef - settle in SI and mature to adult forms:
eggs pass with stool and is eaten by cows to start cycle over malaise and cramps worms emerge out butthole |
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how can Echinococcus granulosus cause fatal anaphylaxis?
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dog tapeworm
human ingests dog feces with eggs eggs develop into cysts in lung (hemoptysis), liver (liver dysfunction), and brain (headache, focal, neuro deficits) cysts rupture - hundreds of worm released into brain fatal anaphylaxis must be surgically removed |
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What is the #1 helminth (pinworm) in the US?
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enterobius vermicularis
occurs only in humans dx: scotch tape test perianal pruritis, especially at night ingest eggs - hatch in small intestine - mature to adults - migrate to colon - mate - at night, female migrates to anus to lay eggs |
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What is the difference between Necator americanus and Ancylostoma duodenale?
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AD - same pathogenesis, properties, and clinical findings as necator (except this one has teeth) - tropical areas
NA - american hookworm (rural SE US) - pruritis at entry site, diarrhea, vomiting, abdominal pain, Fe-deficient anemia walk in bare feet or recline on moist soil, grass - larvae penetrate skin - enter blood - enter lung - ascend - wallowed - go to small intestine - mature - feed on blood of GI capillaries and produce eggs that pass with stool |
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What tapeworm is common in undercooked pork or BEAR or seal?
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trichinella spiralis
causes trichinosis fever, myalgia, periorbital edema, eosinophilia +/- CNS and cardiac symptoms ingests cysts - cysts excyst in SI - mature - mate - produce eggs - hatech - larvae penetrate gut wall and enter blood - enter many organs and enter skeletal muscle - develop into cysts |
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What is a cause of elephantiasis?
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Wuchereria bancrofti
causes filariasis (massive lymph node obstruction with limb edema) and elephantiasis (advanced filariasis) asymptomatic initially - fever, lymphangitis, cellulitis - lymph node welling, edema and fibrosis of legs and genitals mosquito bite - larvae enter skin - enter and reside in lymph node - mature to produce microfilariae - enter blood |
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What tapeworm causes the skin to have a "crawling movement" under the skin?
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dranunculus medinesis
guinea fire worm - dranunculiasis crawling movement under skin - multiple burning, pruritic ulcerated and blistered papules |
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What does ancylostoma caninum/braziliense cause?
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cutaneous larva migrans (creeping eruption)
from cats and dogs very pruritic curvilinear reddened lesions walk barefoot on grass, soil contaminated with dog and cat feces - larvae penetrate skin - migrate through subq tissue - causes inflammatory response |
