Parasitology practice 1/Health Sciences

1. College of Health Sciences
Dep. of Medical Laboratories
Parasitology Practice
3rd stage
Lecture 1
Dr.: Shameeran S. Ismael
BVM & S, M.Sc Medical Microbiology(Parasitology),
PhD Molecular Parasitology
11/28/2020

2. – Confirmation of clinical suspicion
– Identification of unsuspected infection
Purpose of laboratory diagnosis :

3. • A portion or segment that is representative of a whole
body, is taken for analysis or testing, ex., stool
sample, blood sample, urine sample, etc…..
Sample or Specimens:

4. Types of specimens which can be examined
for diagnosis of parasites:
1.Natural secretions: stool, sputum, and urine are used to
detect lumen dwelling parasites of GI, pulmonary and
genitourinary tracts.
2. Blood - usual specimen for detection of blood and tissue
parasites.
3.Skin scraping
4. Biopsy and Autopsy

5. • Stool specimen are examined for detection of protozoa ,
helminthes larvae or eggs.
• The stages of protozoa found in stool samples are
trophozoites , cysts or Oocysts.
• The stages of helminthes usually found in the stool
samples are eggs and larvae, through whole adult worms
or segment of worms may also be seen.
1.Stool or fecal Specimen

6. Stool sample collection:
• Sample is collected in clean, dry container
• Handled carefully
• The container with the specimen should be
clearly labeled with the following:
o Date and time of collection.
o Species of patient
o Sex of patient
o Age of patient
o Time and readable number
.

7. • Liquid and soft stool examined within 15 min
• Not mixed with urine or disinfectant (as they will kill
trophozoites) and free from debris
• If the stool have to send or taken to a laboratory, it
should be examine immediately after the sample had
been taken

8. • If immediate examination is not possible, the stool
samples should be stored in the refrigerator for few
hrs ( not more than 24 hrs.)
• Any worm appears in the stool, it should be preserved
in 5-10% forlmaline or 70% alcohol solution.

9. • For receiving the specimens, it is stored by adding
few drops of 3% formalin for saving larvae and eggs.
• For samples send through the post, the addition of
twice the fecal volume of 10% formalin to the feces
will minimize development and hatching of eggs.
• 10% formalsalin (5%formalin + 5% saline) is
prepare for protozoan preservation.

10. • If the patient has been treated with anti-diarrhea
preparation containing bismuth or cooline, mineral or
oral contrast material (barium) or antibiotics, therefore
repeating fecal examination 5-10 days after treatment
should be done

11. • Entamoeba histolytica (Trophozoite and cyst)
• Giardia lamblia (Trophozoite and cyst)
• Ascaris lumbricoides (larval and adult)
• Faschiola hepatica and schistosoma spp.
(japonicum and mansoni) eggs
• Oocyst of sporozoa
Expected parasites in stool:

12. • Required equipment: we need the followings:
1. tubes.
2. Sterile cotton, wool, or swabs.
3. Sterile lancet.
4. Slides.
5. Disinfect puncture site with
I. 70% alcohol
II. Povidone-iodine
II. Blood Specimen

13. • Blood and Lymph is stored in small tubes containing
aticoagulant or fresh smear is prepared.
Expected parasites in blood smears:
• Trypanosoma Spp.
• Leishmania Spp.
• Plasmodium Spp.

14. • Containers for collection of urine should be
wide mouthed, clean and dry.
• Should be labeled with basic information
associated with patient as in fecal collection
III. Urine collection

15. • Should examined directly or within 1 hr.
(Trophozoite of Trichomonis vaginalis)
• If not, keep it in the refrigerator at around 4ºC for no
longer than 24 hours.
• Preservative used to preserve urine samples such as
Hydrochloric acid, Boric acid, Glacial acetic
acid, Formaldehyde, etc.,
Preservation of Urine

16. • Trichomonas vaginalis (Trophozoites)
• Schistosoma haematobium
Expected parasites in urine

17. • Proper cleaning and drying of the site before scraping.
• Scrapings are made from the center and the margin
• Slide and cover slip
• Normal saline or mineral oil
• Using aseptic technique , clean the area in and over the
lesions with sterile saline and sterile gauze prior to
collection.
IV. Skin Scraping

18. • Debride skin lesions, removing the crust and
any purulent exudates with the moistened
gauze. Explore the base of the lesion with a
sterile moistened swab rolling the swab
through any visible exudates. Replace the
swab in the gel tube, label and transport to the
laboratory promptly.

19. • Amastigote of Leishmania tropica.
(cutaneous leishmaniasis)
• Onchocerca
Expected parasites in skin scraping:

20. V. Sputum sample
Sputum should be obtained from the lower
respiratory passages not saliva.
Sputum specimens should be collected first
thing in the morning

21. • Strongyloides larvae,
•Ascaris larvae,
•Hookworm larvae.
•Entamoeba histolytica (amebic lung abscess)
Expected parasites in Sputum:

22. VI. Vaginal discharge
 Vaginal discharge is used for the demonstration of
trophozoites is usually done by preparing wet mounts
made from vaginal swabs or scrapings.
 If the specimen cannot be examined immediately,
it should be preserved in PVA and stained smears
examined later
 Trichomonis vaginalis trophozoite

23. VII. Tissue Biopsies:
Tissue specimens, including biopsy, surgical or
necropsy specimens, may be collected for the
detection of free-living amebae (Naegleria,
Balamuthia, and Acanthamoeba).
Encysted Larva of Trichinella spiralis in
muscles.

24. I. Stool examination

25. Examination of the stool sample:
There are two types of method for examination of
stool sample in for detection and identification of
parasites:
A. Qualitative Methods:
I. Macroscopic or gross examination
II. Microscopic examination:

26. II. Microscopic examination:
1. Direct stool smear
2. Concentration methods:
a. Floatation technique
b. Sedimentation techniques
c. Telmann Method
d. Baerman Method.
e. Adhesive Tape Method

27. B. Quantitative Stool Methods:
1.MacMaster Method
2. Stoll Method

28. Thanks for attention