Parasitology Flashcards
Mention 2 protozoa that are susceptible to metronidazol!
Entamoeba histolytica Giardia lamblia Trichomonas vaginalis
What are the 3 modes of transmission for human Toxoplasma gondii infection?
Eating undercooked meat containing tissue cysts,
Contact with cat feces or consuming food or water containing oocysts Transplacental transmission
Which protozoon may infect the human foetus transplacentally and cause developmental malformations?
Toxoplasma gondii
Which species are the causative agents of malaria?
Plasmodium vivax, P. ovale, P. malariae, P. falciparum, (P. knowlesi)
What is the definitive (ultimate) host of Plasmodium species?
female Anopheles mosquito
What is the laboratory diagnosis of malaria?
Giemsa-stained blood smears. Thick smear is used to screen for the agent, thin smear is used to identify the species.
How long is the erytrocytic cycle of Plasmodium vivax and P. ovale?
48 hours
How long is the erytrocytic cycle of Plasmodium malariae?
72 hours
What is the causative agent of malignant malaria?
Plasmodium falciparum
Which Plasmodium species may cause relapse of malaria due to presence of hypnozoites?
Plasmodium vivax, P. ovale
Mention a potentially fatal complication of Plasmodium falciparum infections!
cerebral malaria
Mention an agent that may be effective in the treatment of acute malaria attack!
chloroquine, quinine, artemether+lumefantrine, etc.
Mention an antimalarial drug active against hypnozoites!
Primaquin
How can one diagnose the African sleeping sickness disease?
Giemsa-stained blood smears are used for direct demonstration. Serology may be helpful
What are the causative agents of African sleeping sickness?
Trypanosoma brucei gambiense and rhodesiense
Specify the 3 forms of leishmaniasis!
cutaneous, mucocutaneous and visceral
How can one diagnose amebic dysenetery?
Microscopic demonstration of E. histolytica cysts and trophozoites from feces
How can one diagnose Trichomonas vaginalis infection?
Direct demonstration of protozoa in wet mount or stained smear of clinical specimens (vaginal, urethral or prostatic secretions). Isolation by culture.
What is the definitive (ultimate) host of Echinococcus granulosus?
dog
How can one diagnose intestinal taeniasis?
Demonstration of characteristic proglottis and eggs (ova) in faeces.
How can one diagnose Hymenolepis infection?
Demonstration of eggs (ova) in faeces
Mention a worm species for which ab ano ad os auto-reinfection is characteristic in childhood!
Enterobius vermicularis
Mention 2 worm species that migrate through the human lungs in the larval stage!
Ascaris lumbricoides Ancylostoma duodenale Necator americanus Strongyloides stercoralis
How can one diagnose Ascaris infection?
Demonstration of eggs (ova) in faeces
How can one diagnose trichuriasis?
Demonstration of eggs (ova) in faeces
How can one diagnose Enterobius infection?
Demonstration of eggs (ova) recovered from perianal skin (Scotch tape technique). Not from feces!
Mention 3 tissue infecting filarial nematodes!
Wuchereria bancrofti Loa loa
Oncocerca volvulus
How is human Fasciola hepatica infection acquired?
By eating aquatic vegetation containing encysted larvae (Rarely: by eating raw sheep liver containing adult worms)
What disease is caused if humans are infected per os with Taenia solium eggs?
human cysticercosis (encysted larvae in brain, eyes, etc.)
How is human Trichinella spiralis infection acquired?
By eating raw or undercooked meat containing encysted larvae
Mention 2 helminths whose larvae enter the human body by penetrating the intact skin!
Schistosoma Ancylostoma duodenale Necator americanus Strongyloides stercoralis
Which developmental form of Echinococcus granulosus can occur in humans?
Hydatid cyst
What are the definitive, and the intermediate hosts of Taenia saginata, respectively?
definitive host: human intermediate host: cattle
What are the definitive, and the intermediate hosts of Taenia solium, respectively?
definitive host: human intermediate host: swine (pig)
What is the infectious form of Strongyloides stercoralis?
filariform larva
What is the infectious form of Trichuris trichiura?
embryonated egg
Which form of Taenia saginata is infectious for humans?
cysticercus (in beef)
Is autoreinfection possible in Ascaris lumbricoides infection? If yes, when?
No, the eggs must mature in the soil for several days to become infectious (embryonated)
Is autoreinfection possible in Strongyloide stercoralis infection? If yes, when?
yes, especially in immunosuppression (for example: AIDS)
Is autoreinfection possible in Enterobius vermicularis infection? If yes, when?
yes, the eggs become infectious in a few hours, and ab ano ad os autoinfection may occur (especially in children)
