Parasitology III – Flashcards
Unlock all answers in this set
Unlock answersquestion
| How many worms/day does toxocara canis release? |
answer
| 200,000 |
question
| Where do toxocara canis eggs mature? |
answer
| in soil for 2-3 weeks and remain viable in moist soil for years |
question
| Which tissues can be invaded by toxocara canis larvae? |
answer
| ANY TISSUE! esp, liver, lungs, heart, skeletal, muscle, brain, eye |
question
| What determines the severity of toxocara canis symptoms? |
answer
| number/location of lesions and host sensitization to larval antigens |
question
| What symptoms of toxocara canis are specific to children? |
answer
| fever and enlarged liver |
question
| What are the severe symptoms of toxocara canis? |
answer
| skin rash, enlarged spleen, asthma, recurrent pulmonary infiltrates, abdominal pain, sleep, behavioral changes, neurological defects, convulsions |
question
| How does toxocara canis cause death? |
answer
| respiratory failure, cardiac arrhythmia, brain damage |
question
| What is the illness caused by toxocara canis called? |
answer
| visceral larva migrans (VLM) or ocular larva migrans in older children/adults |
question
| How long does visceral larva migrans persist? |
answer
| weeks to months |
question
| What are the eye symptoms of toxocara canis? |
answer
| unilateral strabismus (squint), decreased visual acuity |
question
| What are the findings on eye exam of a person with toxocara canis? |
answer
| granulomatous endophthalmitis due to diffuse chronic inflammation due to dead larvae |
question
| How do you definitively diagnose toxocara canis? |
answer
| demonstration of larva in liver biopsy or at autopsy |
question
| How do you treat toxocara canis? |
answer
| corticosteroids may be lifesaving for acute disease. Antihelminthics such as albendazole or mebendazole |
question
| Ancylostoma braziliense are found where in the environment? |
answer
| larvae hatch from eggs in dog/cat feces in warm, moist, sandy soil |
question
| How does ancylostoma braziliense infect humans? |
answer
| causes skin infection by hookworm larvae , the larvae do not develop further in humans --> migrate within the skin for weeks to months |
question
| What are the symptoms of Ancylostoma braziliense? |
answer
| pruritic raised long red lesions (10-20cm). Scratching it can lead to secondary bacterial infection. |
question
| What causes Loffler's syndromoe? |
answer
| 50% of individuals with ancylostoma braziliense develop this disease due to pulmonary infiltrations |
question
| What are the symptoms of Loffler's disease? |
answer
| pulmonary manifestation; wheeze, cough, eosinophilia in periphery |
question
| What is the treatment for ancylostoma braziliense? |
answer
| albendazole, ivermectin, and topical thiabendazole antihistamines to control itching and antibiotics to control secondary bacterial infection |
question
| Where do you get trichinella spiralis from? |
answer
| eating undercooked pork |
question
| Where does the adult trichinella spiralis live? |
answer
| in the intestinal mucosa of meat-eating animals |
question
| Where do the larvae of adult trichinella spiralis go? |
answer
| vasculature--> heart, pulmonary capillaries, systemic circulation and distributed throughout body |
question
| What are the relatively mild/moderate symptoms of trichinella spiralis? |
answer
| usually asymptomatic; nausea, abdominal pain, diarrhea (within 2 days of eating contaminated meat), fever, muscle pain/tenderness, weakness, eyelid swelling, maculopapular skin rash, small hemorrhages beneath conjuctiva and fingernails. |
question
| Is trichinella spiralis fatal? |
answer
| not usually but extremely heavy infections can be fatal (1,000-5,000 larvae per gram tissue) |
question
| What are the symptoms of severe trichinella infection? |
answer
| hemoptysis (coughin gup blood/sputum from airways), pulmonary consolidation, electrocardiogram anomalies/tachycardia/heart failure, encephalitis, meningitis, polyneuritis (peripheral nerves), delirium, pychosis, coma, death |
question
| How do you diagnose trichinella spiralis? |
answer
| eosinophlic leukocytosis (15-50%) 2nd week of illness onwards, high serum IgE, elevation of muscle enzymes, ELISA antibodies against worm, muscle biopsy |
question
| What's the treatment for trichinella spiralis? |
answer
| mebendazole, albendazole (to stop larvae production), corticosteroids in severe infections |
question
| Which parasite is an intestinal nematode of raccoons? |
answer
| balysascaris procyonis |
question
| Which disease has similar symptoms to Toxocara canis but is often more fatal? |
answer
| Balysascaris procyonis |
question
| Which tissues does Balysascaris procyonis enter? |
answer
| eye/neural tissue |
question
| How long after infection with balysascaris procyonis do symptoms start? |
answer
| 1 week |
question
| What are the symptoms of balysascaris procyonis? |
answer
| nausea, tiredness, liver enlargement, loss of co-ordination, lack of attention, loss of muscle control, blindness, coma |
question
| How do you diagnose Balysascaris procyonis? |
answer
| ocular larva migrans; sensitivity to light, inflammation of eye, blindness. Symptoms of visceral larval migrans; swelling/tenderness of internal organs (liver), eyelids pulmonary involvement= cough/asthma-like symptoms/chest pains |
question
| How do you treat balysascaris procyonis? |
answer
| albendazole, early treatment important! if ingested raccoon feces, get prophylactic albendazole. If already has disease, use corticosteroids to reduce host inflammatory response |
question
| How long can schistosoma sp. live in humans? |
answer
| decades, causing progressive damage to essential organs |
question
| How do you get infected with schistosoma sp.? |
answer
| cercariae released by snail and swimming in water penetrates human skin |
question
| How do eggs of schistosoma end up in feces? |
answer
| adults migrate to mesenteric veins, lay eggs, and then veings drain to the liver and liver puts them in the intestines |
question
| What are the symptoms of early stage schistosoma sp? |
answer
| itchy papular skin rash (swimmers' itch); avian schistosomes, disease self-limiting; fever, headache, abdominal pain for 1 to 2 weeks (schistosomes begin migrating to liver) |
question
| What are the symptoms of intermediate stage schistomsoma sp? |
answer
| 1 to 2 months; acute febrile illness, cough, urticaria, arthralgia, lymphadenopathy, hepatosplenomegaly, abdominal pain, diarrhea |
question
| What is Katayama syndrome? |
answer
| acute disease caused by schistosoma sp. infection that causes leukocytosis, marked peripheral eosinophilia, and high levels of IgM, IgG, and IgE |
question
| What happens in the chronic stage of schistosoma sp? |
answer
| eggs retained (rest are shed) induce inflammation and fibrotic scarring: eosinophilic granulomas This often leads to obstruction of blood flow |
question
| How do you diagnose schistosoma sp? |
answer
| recover of eggs in feces (s. mansoni/s. japonicum) and/or urine (S. haematobium) -determine egg viability in water to hatch/movement inside egg |
question
| How do you treat schistosoma sp? |
answer
| antihistamines and corticosteroids to control host inflammatory responses/immunopathology. Also, praziquantel to kill the worms |
question
| What worms causes filiaris/elephantiasis? |
answer
| burgia malayi and wuchereria bancrofti |
question
| What fly transmits onchocerca volvulus? |
answer
| black fly |
question
| What organism causes river blindness? |
answer
| onchocerca volvulus |
question
| How do you get infected with Loa Loa and where do they end up? |
answer
| fly subcutaneous tissue (eye) |
question
| How do you get echinococcus granulosis and where in the human body does it live? |
answer
| feco-oral route from other hosts like dogs/sheep. Causes hydatid cyst in liver/lung etc. |
question
| How do you get chlonarchis sinensis and where in the human does it live? |
answer
| eating fresh water fish; biliary tract |
question
| How do you get paragonimus westermani and where does it live in the human host? |
answer
| undercooked shellfish and makes cavitary lesions in the lung |
