Diagnosis Of Parasitic Infections Flashcards
Human parasites are organisms that live on or in a person and derive nutrients from that person (its host).
3 types of parasites:
______
_________
_________
protozoa
helminths (worms)
ectoparasites
stool specimen
Should be ______
______ substances should be avoided when stool specimens are collected
Collect before ___,_______,______,______ , and ______ agents.
Collection delayed by ________ if these agent have already been administered
fresh
Interfering
barium, mineral oil, bismuth, antibiotics, antimalarial
5 to 10 days
COLLECTION METHOD of stool specimen
Clean containers or fixative vials.
Avoided contamination with ____ or____
Labeled with patient name, time and date of collection
If on admission, patient is given bedpan with instructions on how to avoid contamination with urine , a _______ of the specimen, especially that which contains ___,——, or _____ is transferred into a clean, dry, leakproof container.
When the specimen contains worms or tapeworm segments, they are ___________
urine or water
portion (about a spoonful)
mucus, pus, or blood
put in separate containers .
NUMBER OF SPECIMENS for a stool sample
Normal examination for stool parasites before therapy includes ____ specimens.
Post therapy specimens not collected unless ___________________
3
patient becomes symptomatic again.
COLLECTION TIMES of stool samples
Three specimens collected on separate days.
Within no more than ___ days.
Exception: patient with _______, organisms might be missed because of ____________ related to ____ loss.
10
severe, watery diarrhea
tremendous dilution factor
fluid
SPECIMEN TYPE, STABILITY, AND PRESERVATION in stool sample
Fresh specimens mandatory for recovery of _________
Liquid stool should be ______ within _____ of passage (______)
Soft stool examined or preserved within ______ of passage ( ______ ) dientamoeba fragilis trophozoites
Formed stool should be examined or preserved within ______ of passage.
motile trophozoites.
examined or preserved; 30 minutes ; trophozoites
1 hour ; trophozoitess & cysts
24 hour
List 4 stool fixatives
Formalin, sodium acetate- acetic acid-formalin (SAF), schaudinn’s fluid, and polyvinyl alcohol (PVA)
PRESERVATION OF STOOL
SPECIMENS
Delay in receiving stool specimens, place in ______
Keep in mind, a _______ is mandatory.
May want to perform screening methods:______ or ________.
Make sure the fixative is compatible with the kit you are using.
Disposal regulations for compounds containing _____ are becoming more STRICT
fixatives
permanent stained smear
fluorescent-antibody (FA) or enzyme immunoassay (EIA)
mercury
COLLECTION OF BLOOD
Parasites: _____,________,______,______ and microfilariae.
Collect fresh blood (____ anticoagulant)
Smears prepared within _____ after the specimen is drawn.
Plasmodium, Babesia, Trypanosoma, Leishmania,
EDTA; 1 hour
In a blood sample, One negative specimen rules out the possibility of a parasitic infection.
T/F
F
One negative specimen does not rule out the possibility of a parasitic infection.
Microscopic examination faeces
Direct wet mount:
Thin ______ of small amount of faeces
Few drops of ________
________ mount
Look for (x10 or X40)
Protozoa (_______), cyst, eggs and larva of helminths, crystals (____________)
emulsion
saline
Lugol’s iodine
trophozoite
charcot leyden
Molecular diagnosis
(using stool sample)
If an unequivocal identification of the parasite can not be made, the stool specimen can be analyzed using molecular techniques such as ______________.
polymerase chain reaction (PCR)
Molecular diagnosis
(using stool sample)
PCR amplified fragments can be analyzed by using _________ (RFLP) or _______ if further characterization is needed.
restriction fragment length polymorphisms
DNA sequencing
Blood examination
Fresh capillary blood of _____ or ____
(Arterial or Venous?) blood collected in ______ (anticoagulant)
finger or ear lobe
Venous
EDTA
Blood examination
Blood sample will be used for :
Microscopic examination( ________, ___-, _______ for microfilaria).
Molecular diagnosis
Detection of parasite antigen
Isolation of organisms
Special tests
Thin Smear; Thick smear
Wet mount
Microscopy of blood
Examination of thick and thin peripheral blood smears stained with _____ or other appropriate stains is used for detection and identification of species of Plasmodium, Babesia, Trypanosoma, Brugia, Mansonella , and Wuchereria
The sensitivity of these methods may be enhanced by concentration procedures (eg, _____ test, ________, and _______).
•
Giemsa
buffy coat
filtration
Thick blood film
Screen (small or large?) amount of blood (____ infection)
Can be stained ____
Large
light
latter
Thin blood film
In ______, Parasitized red blood cells and parasites
___________ identification
Malaria
Definite species
Microfilaria
Sample collection according to ______ of microfilaria
Concentration by _______ or ______ (examine the filter)
periodicity
sedimentation
membrane filtration
Sputum examination
Microscopic examination of sputum can identify:
_________ eggs
_______ larva
________ larvae
hookworm larvae, and rarely _______
Paragonimus westermani
Strongyloides stercoralis
Ascaris lumbricoides
Entamoeba histolytica.
Sputum should be obtained from the __________ not _____
lower respiratory passages
saliva
Sputum specimens should be collected ___________
first thing in the morning.
Vaginal swabs
Demonstration of _________ trophozoites is usually done by preparing _________ made from vaginal swabs or scrapings.
Trichomonas vaginalis
wet mounts
Tissue Specimens for Free-living Amebae (FLAs)
Tissue specimens, including _____, ___________ specimens, may be collected for the detection of free-living amebae (Naegleria, Balamuthia, and Acanthamoeba).
used for
•Tissue slides stained with ________
•Unstained slides (for _________).
•Unfixed _____ tissue or CSF for PCR.
•Unfixed _______ (for Acanthamoeba).
•______-embedded tissue block.
biopsy
surgical or necropsy
hematoxylin and eosin (H&E).
indirect Immunofluorescence, or IIF
corneal scrapings
Paraffin
The most reliable and widely used technique for demonstrating pinworm eggs (__________) is the _______ or ______ procedure.
Enterobius vermicularis
cellulose tape or swube tube
Cellulose Tape or Swube Tube Procedure for Demonstration of Pinworm Eggs
The _____ part of the swube tube or tape is applied to the ______ first thing in the morning.
Specimens should be collected on _______ (prior to or after?) bathing.
• If an infection is present, ____ and sometimes _____ of Enterobius vermicularis will be present
on the tape and can be seen under the microscope
adhesive
perianal area
three consecutive mornings; prior
eggs; adult worms
Urinary schistosomiasis
• Presence of S. _______ eggs in urine is diagnostic for Eggs usually shed in the urine around _____, so an optimum urine specimen for diagnosis should be collected at ____.
The specimen should be immediately centrifuged at ____ × g and the sediment examined by _____
haematobium
midday; noon
400; wet mount.
Trichomonas vaginalis
______ trophozoites may also be found in the urine, especially in infected ____ patients.
Urine specimen should be centrifuged at ____ × g, the sediment mixed with a drop or two of _____, and examined by ____
Motile
male
400; saline; wet mount
Temporary stains, such as _______ is helpful to see T. Vaginalis
methylene blue
