protozoa Flashcards
what is the feeding form of a protozoa ?
trophozoite
what is the more durable form of protozoa that is found in nature?
cysts
what is the transmission associated with GI protozoa ?
feco oral
what are the two blood parasites ?
malaria
babesia
where are giardia cysts found ?
wet environment in mountain stream water
what effect does giardia have on the body ?
affects the small intestine
bloating foul smell and fatty diarrhea
stools that float
how is a diagnosis of giardia made ?
cyst in stoll
trophozites in stool
ELISA for giardia antigen in stool
what is the classic case of giardia ?
camper or hiker that comes complaining of bloating and fatty stools
what is the immune association with giarda ?
IgA deficiency is associated with a higher rate of giardia infection
brutons ammaglobulinemia
selective IgA deficiency
how is giardia treated ?
metronidazole
what is the cause of amebiasis or amebic dysentry ?
entamoeba histolytica
what is the effect of histolytica n the body ?
invades the tissue of the small bowel - causes bloody diarrhea
abscess in the liver - right upper quadrant pain
what is special about liver abscess caused by entamoeba ?
anchovy past exudate in surgery
what is the most probable cause of infection in a traveler with right upper quadrant pain , bloody diarrhea ?
amoebiasis by entamoeba histolytica
how is a diagnosis of entamoeba ?
stool microscopy
serology
multiple nuclei seen in cyst
ingested multiple red blood cells on microscopy ?
entaomeba histolytica
what is the treatment for amoebiasis, and what is the treatment for asymptomatic carriers ?
metronidazole
asymptomatic carriers : idoquinol
what is sen on biopsy of the small bowel in amoebic dysentery ?
a flask shaped ulcer
what is the classic case of ameobiasis ?
immigrant
RUQ
bloody diarrhea
what type of patient is associated with cryptosporidium ?
immunocompromised patients
the more immunocompromised the worst
what stain is used for cryptosporidium infection ?
acid fast stain - they turn purple
what is the treatment for cryptosporidium ?
immunocompetent : nitozoxanide
immunocompromised : anti retroviral
why is it a problem when immunocompromised patients get toxoplasmosis ?
because it may enter a latent phase and reactivate later
what are tho major disease processes associated with toxoplasmosis ?
HIV CNS disease
congenital toxoplasmosis
when can toxoplasmosis cause significant CNS disease ?
only in the immunocompromised specifically HIV patients
what is seen on Brain imaging in patients with HIV CNS disease ?
multiple ring enhancing lesions
brain abscess
what is the problem with toxoplasmosis and pregnancy and what are the symptoms ?
crosses the placenta
the classic triad - chorioretinitis
hydrocephalus - enlarged ventricles
intracranial calcification
what are the methods of diagnosis of toxoplasmosis and what are the results seen?
serology or biopsy
IgG or IgM antibodies
IgM if the infection appears within one week
IgG antibodies rise within two weeks
what is seen on biopsy of toxoplasmosis?
tachyzoite with a giemsa stain
what is the treatment for toxoplasmosis and what is the mechanism ?
sulfadiazine/ pyrimethamine
blocks the THF synthesis pathway
where is naegleria fowleri found and how does it cause disease ?
in contaminated water and ponds
it travels up the nose and can reach the cribriform plate causing meningoencephalitis
what is the classic case associated with naegleria fowleri ?
recent history of swimming
fever, confusion and a stiff neck
often fatal
what is african trypanosomiasis caused by and what is the other name for it ?
all caused by tsetse fly
african sleeping sickness
what are the early and late features associated with african trypanosomiasis ?
early : fever and arthalgia
late : somnolence, coma
how is. diagnosis of african tryponomiasis made ?
visible in blood smear
why is there a recurring fever in african trypansomiasis ?
antigenic variation
variant surface glycoprotein (VSG)
what are the infections carried by ixodes scapularis ?
anaplasma
borrelia
babesiosis
so co infection is common and must check for the other when infected with one
which cells are infected by babesiosis ?
red blood cells
which type of patient is at increased risk of babesiosis ?
asplenic patients
what are the symptoms of babesiosis ?
fever
spleenomegaly
hemolytic anemia
how is a diagnosis of babesiosis made ?
blood smear , rings form maltese crosses
PCR test is also used
what is the treatment of babesiosis ?
azithromycin
atovaquone
what is the cause of chagas disease ?
trypanosoma cruzi
how is trypanosoma cruzi transmitted ?
through reduviid bug bite
nest in the cracks and holes of housing
what is the presentation of chagas disease ?
acute phase - nonspecific, febrile illness
chronic chagas - heart, oesophagus and colon affection
what is the cardiac effect, eosophageal effect, and colonic effect of chagas disease ?
cardiac: right and left heart failure
high prevelance of ventricular thrombi
pulmonary embolism/stroke
edophagus: achalasia, megaesophagus (dilation)
colon: megacolon due to severe constipation
how can you diagnose the acute phase and chronic phase of chagas disease ?
acute phase: blood smear trypomastigotes
chronic phase : serology IgG antibodies
what is the treatment for chagas disease ?
acute phase only nifurtimox
what is the cause of leishmaniasis and what cell is affected ?
sand fly
macrophages are infected
what are the two forms of leishmaniasis ?
cutaneous leishmaniasis - large ulcer with indurated border
visceral leishmaniasis - fever, painful splenomegaly, pancytopenia
how is the visceral for of leishmaniasis diagnosed ?
by taking a biopsy of the affected organs
bone marrow or spleen
what is found in macrophages infected by leishmania ?
amastigotes
what is the treatment for leishmania ?
amphotericin B
sodium stibogluconate
where is trichomonas vaginalis normally found ?
lives in the urogenital tract
and is sexually transmitted
what is the presentation of trichomonas vaginalis in men vs in women ?
men: usually asymptomatic
women: vaginitis, itching and foul smelling discharge
how is the diagnosis of tichomonas vaginalis made ?
using a wet mount
vaginal pH will belevated
what is the treatment for trochomonal vaginalis ?
metronidazole for patient and partner
what are the three possible causes of vaginitis ?
gardnerella vaginalis
candida
trichomonas
what is the key feature seen in gardnerella vaginalis and what is specific about the odor ?
clue cell seen
fishy odor
what test is used to diagnose bacterial vaginitis ?
whiff test : KOH makes a fishy smell
what is the test associated with candida vaginitis ?
KOH prep
what is unique about trichomonas vaginitis ?
strawberry cervix
