Parasites Flashcards
Define Parasite
A parasite is an organism that lives in another organism and gets its food at the expense of its host
What is a parasite more complex then
bacteria
What are the three classifications of parasites
Protoza
Helminths
Arhropods
What are the features of a protozoa parasite
One cell organism
Free living
Where do protozoa multiply
Multiply in humans
What is a protoza called if found in small intestine or blood
Fecal oral route
Arthropod vector
What are three example of protozoa
Malaria
Amoebae
flagellates
What are three infections caused by protozoa parasite
Malaria
Amoebic Dysentery
Leishmaniasis
What is the parasite injected into the skin by mosquitoes called which causes malaria (what is the most deadliest form of the parasite)
Plasmodium
plasmodium falciparum
What does plasmodium parasite do in infected humans
Invade RBC, multiply and lyse cells
How is malaria diagnosed
Thick and thin blood films H
How is malaria controlled
Nets
Prophylaxis
Define sporozates
infective agent introduced into a host
Define merozoites
a sporozates capable of capable of sexual or asexual development
Where does plasmodium sporozates mature as meterozite
The liver
What does amoebic dysentry cause
Infection of the intestine causing diarrhoea with blood or pus
What parasite causes amoebic dysentry
Entamoeba Histolytica ingesting RBC
Define trophozoite
a growing stage in the life cycle of some sporozoan parasites, when they are absorbing nutrients from the host
How is amoebic dysentry diagnosed
Microscopy of cyts formed in stools
What can occur in amoebic dysentry if disease progresses
Liver abscess
What causes Leishmaniasis
leishmania transmitted by the bite of sandflies
What does Leishmaniasis cause
Skin or mucosal (internal organs) ulceration
How is leishmaniasis diagnosed
histology of biopsy material
What are the three types of Helminths (worms)
Nematodes - round worms
Cestodes - tapeworms
Trematodes - flatworms
What re two examples of nematodes round worms
Enterobius vermicularis
Ascaris lumbricoides
How are round worms diagnosed
ova seen in faeces by microscopy
What are enterbius vermicularis
threadlike bacteria that are excreted in the stool, laying eggs in the rectum at night
What is the route of Ascaris lumbricoides round worms
ingested eggs hatch in intestine, larvae carry to lungs swallowed again and inhabit and develop in small intestine
Ascaris lumbricoides are asymptomatic but a mass of the round worms can cause what
obstruct small intestine or common bile duct
What are the examples of tape worms
Taenia saginata (beef) and Taenia solium (pork) Echinococcus
What is the intermediate then definitive host for taenia tapeworms
Larval cysts ingested in meat
Adult tapeworm in human
What is Cysticercosis
infection caused by the larvae of the parasite Taenia solium foreign cyts in human tissue
What is the life cycle of tape worm parasite Echinococcus
Carried by dogs, humans ingest eggs, form cyts in the liver
What is an example of a trematode flatworm and where is it found
Schistosomiasis
Fresh water
What is the intermediate host for Schistosomiasis
Snails
What is the pathway of Schistosomiasis flatworms in a human
Penetrate human skin, then migrate through lungs to liver where they mature, then they migrate to bladder and lay there eggs
What disease can Schistosomiasis flat worms cause
Katayamia fever
Haematuria
Bladder cancer
What is also accompanied by a flat worm infection
Increased WBC
Elevated IgE
Detection methods
Microscopy
Serology (useful for deep location)
