Parasites Flashcards
What is a definitive host?
one is which a parasite reproduces
What are the life stages of parasites?
Egg
immatures=larve(nymph)
adults
What is an intermediate host?
one in which development occurs, but no reproduction
How do you diagnose intestinal parasites, blood parasites, and tissue parasites?
intestinal parasites- fecal specimens
blood parasites- thick and thin specimens
tissue parasites- biopsy, especially muscle
What are the two types of eukaryotic single celled parasites?
the protozoa and sporozoa
What are the three categories of protozoa?
amoebae, flagellated protozoa, and ciliated protozoa
What is the one type of amoebae given?
entamoeba histolytica
what does entamoeba histolytica cause?
amebic dysentery
What are the two life stages of entamoeba histolytica?
trophozoite- the active feeding stage, pseudopods
cyst- similiar to endospore, resistant to environment and infective
How is entamoeba histolytica transmitted?
cyst is ingested from contaminated foor, water-use of night soil(poop collected in buckets at night and used as manure) increases chance of contamination. can be vectored by flies
What does entamoeba histolytica cause?
cysts rupture in intestine causing bloody diarrhea, if trophozoites enter blood move to liver causing hepatic amebiasis- a collection of puss in the liver
What are the 7 types of flagellated protozoa?
1 Giardia lamblia 2 Trichomonas vaginalis 3 Trypanosoma brucei 4 Trypanosoma cruzi 5 Leishmania donovani 6 Leishmania tropica 7 Leishmania braziliensis
What is beaver fever?
Giardia lamblia
What are the two life stages of giardia lambia?
trophozoite- the active feeding stage
cyst- similiar to endospore, resistant to environment and infective
How is giardia lamblia transmitted and what is its reservoir?
Cysts ingested in contaminated water near beaver populations since beavers are the reservoir
what does giardia lamblia cause?
the cyst excysts in intestine, reproduces and covers the intestinal wall…it interferes with fat absorption, causing fatty stools and diarrhea
What does the 2nd flagellated protozoa trichomonas vaginalis cause and what are the stages of it?
it is the cause of trichomoniasis
trophozite has 4 flagella
NO CYST form
How is trichomonas vaginalis transmitted and what does it cause?
trophozites are passed sexually causing urogenital infections
the pathology is green discharge, itching in females and urethritis in males
What do trypanosomes cause?
they cause trypanosomiasis
What causes African sleeping sickness?
Trypanosoma brucei
what is the life stage of trypanosoma brucei?
life stage is protozoa form called trypanosome, no cyst
how is trypanosoma brucei transmitted?
is vectored by the Tse-Tse fly
What is the pathology of tryanosoma brucei?
in vertebrate host tryponosomes live in the blood, lymph nodes, spleen, and CSF. They do not invade or live in cells but rather in tissue spaces particularly in CNS. Within a few days the animals become emaciated, uncoordinated, and paralyzed…then dies. humans tend to experience mental dullness, tendency to sleep, and finally coma and death
What does trypanosma cruzi cause?
Chagas’ disease (Mexico, South, Central America)
What type of single celled parasite is trypanosoma cruzi?
flagellated protozoa
What is the life stage of trypanosoma cruzi?
life stage is protozoa form called trypanosome, no cys t
What is the transmission of Trypanosoma cruzi?
is vectored by the reduviid bug (kissing bug) via defacation by bug into wound
What is the pathology of acute Chagas’ disease?
Caused by trypanosoma cruzi -
small red nodule called chagoma at bite site
heart, liver, lymph nodes and spleen are infected
symptoms include anemia, nervous disorders, muscle and bone pain, heart failure
death may ensure after 3 to 4 weeks
Most common in children
Pathology of chronic Chagas’ disease?
Caused by tryponsoma cruzi
symptoms are primarily nervous disfunction which may continue for years
individual may be virtually asymptomatic and suddenly die of heart failure
What does leichmania donovani cause and what is it called?
it causes visceral leishmaniasis and is called Kala-azar
How is leishmania donovani transmitted?
it is vectored by the sandfly
What is the pathology of Leishmania donovani?
Invades liver, spleen, and kidney
Causes enlarged liver, spleen, wasting and finally death if untreated in 2-3 years
What happens after treatment of Kala-azar?
a condition known as post-Kala-azar dermal leishmanoid=this is a granulomatis reaction on the skin about 2-3 years after treated
What does leishmania tropica cause?
Cutaneous leishmaniasis or oriental sore
How is Leishmania tropica transmitted?
It is vectored by the sandfly
What is the pathology of leishmania tropica?
red papule form sandfly bite, slow to heal, and scar
What causes mucocutaneous leishmaniasis? what is it also called?
Laishmania braziliensis and is also called esplundia
How is leishmania braziliensis transmitted?
it si vectored by the sandfly
what is the pathology for leishmania braziliensis?
lesions in the junction of the pharynx result in the breakdown of the palate of the mouth and nose
What is the one type of ciliated protozoa?
Balantidium coli
what does balantidium coli cause?
ciliary dysentery
What are the life types of balantidium coli?
large ciliated trophozoite form
cyst form is present
How is balantidium coli transmitted?
Transmitted by fecal contaminated water, particularly associated with infected pig feces
What is the pathology of balantidium coli?
abdominal pain, watery, bloody stools
The next single celled parasite is the sporozoa. What are the 3 types?
Plasmodium
Toxoplasma
Cryptospordium parvum
what does plasmodium cause?
Malaria
What are the 3 life stages of the palsmodium?
Sporozoites= released from mosquito into human host, go to liver, under go asexual reproduction to produce merozoites Merozoites= infect and destroy red blood cells causing symptoms of malaria Gametocytes= produced as a result of erythrocytic stage in RBC, taken up by a female mosquito
In vertebrates what are the two cycles that plasmodium undergoes?
Exoerythrocytic stage- in liver
Erythrocytic stage- in RBCs
What is the malarial pigment from?
merozoites in RBCs produce waste product called malarial pigment
How is plasmodium transmitted?
vectored by Anopheles mosquitos
What are the 4 species of plasmodium?
Plasmodium vivax
Plasmodium malariae
Plasmodium falciparum
Plasmodium ovale
What does toxoplasma cause?
taxoplasmosis
What is the official name of toxoplasma?
Toxoplasma gondii
What host does toxoplasma gondii like?
very low host specificity
what is the definitive host of toxoplasma gondii?
domestic and wild cats
What are the life stages of toxoplasma gondii?
sporozoites are infectious form
sporozoites are within oocyst that passes out in feces
How is taxoplasma gondii transmitted?
ingestion of undercooked infected meat containing toxoplasma oocysts
ingestion of the oocyst from fecally contaminated hands or food
Transplacental transmission
What is the pathology of toxoplasma gondii?
Usually an asymptomatic infection in immunocompetent people
Most sommon cause of intercerebral brain lesions in people with AIDS
Can invade the CNS and may cause blindness, encephalitis, and mental retardation
Infection during 1st trimester is most damaging. Congenital toxoplasma can result in the baby
What is the last (3rd) sporozoa?
Cryptosporidium parvum
Where do you get Cryptosporidium parvum and what does it cause?
It is difficult to detect in water and ingestion of cysts cause watery diarrhea similiar to giardia infection
What are Nematodes?
round worms
What are the 3 types of roundworms transmitted by ingestion of the ova?
1 Ascaris lumbricoides
2 Trichuris trichiura
3 Enterobius vermicularis
What is special about Ascaris lumbricoides?
largest nematode parasitizing the human intestine
What is the pathology of Ascaris lumbricoides?
Adult worms usually cause no acute symptoms, although may cause stunted growth
High amounts of worms in you may cause abdominal pain and intestinal destruction
Migrating worms may block bile duct
During the lung phase of larval migration pulmonary symptoms may occur
What is the scientific name of the whip worm?
Trichuritis trichiura
What is the pathology of the trichuritis trichiura?
Fewer thn 100 worms rarely cause symptoms, and the majority of infections are asymptomatic
Heavy worm burden results in:
Anemia- consume blood cells
Damage to epithelial layer can lead to secondary bacterial infection
in extreme cases prolapse of the rectum can occur
The last of the round worms transmitted by ingestion of ova is?????
Enterobius vermicularis
What is another name for Enterobius vermicularis?
The pin worm and humans are considered to be the only hosts
What are some of the unique features of the life cycle of enterobius vermicularis?
the adult female worm is nocturnal and migrates out of the intestine at night and lays an=bout 20000 eggs on the perianal skin at night. The eggs are transferred to the fingernails by scratching…leading to the eggs being ingested. Eggs then begin the life cycle in the intestines all over again
What are the 3 types of roundworms transmitted by direct penetration of infectious larvae?
1 Ancylostoma duodenale and necator americans
2 Ancylostoma braziliense
3 Strongyloides stercoralis
What is the other name for both ancylostoma duodenale and necator?
American hookworm
What is notable about the life cycle of the american hookworm?
adult female lays 10-20000 eggs a day in intestine- they feed on bacteria in feces- grow up can penetrate bare skin and eventually moves to the lungs
Pathology of the american hookworm?
They can cause lung issues and adult worms feed on blood in the small intestine leading to anemia and malnutrition
What is another name for Ancylostoma braziliense?
dog and cat hook worm
What is the life cycle like of the Ancylostoma braziliense? aka dog and cat hook worm
larva penetrate skin and wander- life cycle is not complete in humans and the wander aimlessly causing creeping eruption-intense itching and eosinophilia
Last of the round worms that has direct penetration of the larva…this one alternates between free-living and parasitic forms?
Strongyloides stercoralis
What are the 3 types of round worm tissue parasites?
1 Anisaka
2 Trichinella spiralis
3 Filarial worms 2 types
Which parasite is in the stomach of marine fish and birds?
Anisaka
how do you get anasaka? what does it cause and is there a treatment?
you get it from ingesting raw fish…it causes intestinal obstruction, pain nausea and vomitting…no drug…surgical only
The 2nd of the round worm tissue parasites is trichinella spiralis. what is its host?
low host specificity, bears, pigs, rats
What is unique abbout the life cycle of trichinella spiralis?
larva are carried via blood to the muscle where they encyst…if not consumed they die and calcify…a human is a dead end host
What is the pathology like for Trichinella spiralis?
light infections may be symptomatic
larval migrations can cause edema, conjunctivitis, fever, and rashes
occasionally can be life threatening
What are the two types of filarial worms?
Wuchereria bancroft and onchocerca
What is wuchereria bancroft also known as?
elephantiasis
What is the vector for wuchereria bancrofti?
mosquito
Where does wuchereria bancrofti cause the most issues?
in the lymphatic system…can cause inflammation…lymph nodes become swollen
in males: scrotum, legs
in females: legs
only circulate in the blood at night
what is the 2nd type of filarial worm?
Onchocerca volvulus
What does onchocerca volculus cause?
river blindness
What is special about onchocerca volvulus worms?
They form nodules under the skin and eventually migrate up through the skin to the eyes. When they do this they cause inflammation “lizard skin” the larvae may cause blindness
Flat worms are aka?
platyhelminthes
Trematoda is a class in which phylum and what is another name for them?
flukes in the phylum platyhelminthees
What are the 4 types of trematoda?
1 Fasciola hepatica
2 Clonorchis sinesis
3 Fasciolopsis buski
4 Schistosomes: the blood flukes
The 1st trematoda is know as the liver fluke what is the scientific name?
Fascoila hepatica
Describe fasciola hepatica
large leaf-shaped parasite of herbivores, that can infect humans accidentally
The 2nd trematoda is known as the chinese liver fluke what is the other name for it?
Clonorchis sinensis
describe the chinese liver fluke
aka clonorchis sinesis and the worm matures in the bile ducts and produces up to 4000 eggs a day for atleast 6 months
The third trematoda in known as the giant intestinal fluke…scientific name?
Fasciolopsis buski
the 4th trematoda matures in the blood stream. name?
Schistosomes: the blood flukes
Has seperate male and female worms
