Parasitic Infections of circ and lymph Flashcards
In what country can sleeping sickness most likely be found?
Sleeping sickness caused by African trypanosomiasis is only found in Africa.
How is sleeping sickness transfered?
This is transferred via the Tsetse fly and some species are able to infect cattle.
What is the name of the west african species of trypanosomes that spreads from human to human?
T. Brucei gambiense
West species is most typically known for causing swellin of lymph nodes in the early stage of infection.
What is the name of the East African trypansosome that spreads from human to human or animal to human?
Brucei rhodesiense
What process allows African Tryanosomiasis to evade the host response?
Antigenic variation, in which the protozoa is able to modifiy its surface glycoproteins.
What two drugs are used to treat African Sleeping Sickness?
The highly toxic Melarsoprol
and
Difluoromethylornithine (DFMO) that is no longer in use due to lack of funding.
What countries are known to harbor Chagas Disease?
South and Central Americas.
Can be aquired in the US but rare and in the southern parts.
What Bug specifically passes Chagas along?
The Reduviid bug by bite following deffication.
What causes the Romana’s sign?
Romana’s sign is a result of rubbing feces into an eye containing Chagomas. This causes periorbital swelling.
What occurs following Chagas disease in:
Acute phase
Intermediate Phase
Chronic Disease Phase
Acute phase: Fever malaise, myalgia, hepatosplenomegally.
Intermediate: Most people in this asymptomatic phase marked with high level of antibodies.
Chronic Disease Phase: Infection of the cardiac muscle and myenteric plexus of the GI can lead to congestive heart failure and megacolon
Megacolon and Congestive heart failure following a bug bite in a pt from South America would be indicitive of what sort of infection?
Indicative of Chagas Disease in the Chronic Disease State.
What is the vector for Leishmaniasis?
Female Sand Flea bite! characterized protozoan marked by long flaggellate.
Canine and Rodents are important resevoirs.
Which Sand Flea species are known to cause visceral Leishmaniasis?
L. Donovani
L. infantum
L. Chagasi
Where does the Leishmaniasis Protozoan hide in the body?
Macrophages of the liver, bone marrow, or spleen.
The term Wasting appearance along with systemic immuno supression and a secondary bacterial/viral infection causing death are all hallmarks of what disease?
Leishmaniasis.
How is Leishmaniasis treated?
Gamma interferon mediated activation of macrophages will aid in treatment along with heavy metals and other drugs with considerable toxicity.
Antibodies dont really help as this pathogen is intracellular.
What four species of Plasmodium cause malaria in humans?
Falciparum
Vivax
Malariae
Ovale
What two species of Plasmodium cause the most cases of malaria?
Falciparum and Vivax
What is the Malarial paroxysm?
This is a synchronous release of merozoites and the lysis of RBCs presenting with alternating flu like symptoms inbetween blood lysing.
Alternates between a cold stage, hot stage, and sweat stage.
How often does the paroxysm occur in Vivax and Ovale species?
Every 48 hours.
How often does the paroxysm occur in malariae and Falciparum species?
malariae occurs every 72 hours
Falciparum occurs more randomly but within every 48 hours.
What are three mechanisms involved in the pathogenesis of anemia?
RBC lyse by the mature asexual intraerythrocytic parasites.
Supression of blood creation by cytokines TNFalpha and IL-1
Destruction of abnormal RBC by the spleen
What sort of RBC does P. falciparum infect?
Infects mature and young erythrocytes thus being dangerous.
What specific blood grouping does p. vivax require for infection
P. vivax can only infect reticulocytes bearing duffy blood group determinants.
What specific blood grouping does P. ovale require for infection?
P. ovale can infect only Duffy negative or positive reticulocytes.
What blood cell type does P. malariae prefer?
Preferes older erythrocytes.
Which Form of Plasmodium would most likely cause severe anermia?
P. falciparum as this form causes the highest ammount of parisitemia with over 20% of RBC being infected.
What diagnosis tool is considered the “gold standard” for malaria?
A blood smear that comes back positive for the parasites.
If purple bananas are seen on a slide what is the pt most likely infected with?
P. Falciforum!
Malaria
If Band Forms are seen in a blood sample what breed of malaria is it?
Typically this will be seen in the plasmodium malariae.
The Malaria immunodiagnosis serves to test what?
Serves to test only for the presence of P. falciparum from other species.
What is the vector for Babesiosis?
Babesia spp are passed along in rodents and cattle by bite of tick.
Where in the US can Babesiosis be found?
Typically found in New England, Upper Midwest, and California.
What population are at highest risk of symptomatic Babesiosis infection?
The elderly
Asplenic
Immunosupressed
What is Filariasis?
Microfilaria?
Filariasis is caused by filarial nematodes transfered from mosquitos that block the lymph system leading to elephantitis in the limbs and scrotum.
Microfilaria are the eggs releaased by the worms.
What are the treatment choices for Filariasis?
Steroids and DEC both of which are harmful to the host.
How is Schistosomias aquired?
The helminth infects snails in freshwater. The worms are released and burrow into humans skin when they are swimming in the water.
Where can these schistosomes be found in the body?
S. mansoni
S. Japonicum
S. haematobium
S. mansoni: venous plexus of the large intestine
S. Japonicum: Venous plexus of the small intestine
S. haematobium: Venous plexus of the bladder.
How is Schistosomiasis diagnosed?
Diagnosed by eggs in feces or urine.
