Stool FEME for ova and cyst (wet mount)

An ova and parasite (O&P) exam is a microscopic evaluation that is used to look for parasites that have infected the lower digestive tract. The parasites are shed from the lower digestive tract into the stool. When thin smears of fresh or preserved stool are put onto glass slides and stained, the parasites (including their eggs (ova) or cysts), may be detected and identified under the microscope. Different ova and parasites have distinct shapes, sizes, and internal structures that are characteristic of their species.

Sample type:

A fresh stool sample transported to the lab within 2 hours or a preserved stool sample, usually multiple samples are collected on different days.

Uses:

The O&P is ordered when you are suspected of having ingested contaminated food or water and have signs and symptoms of a GI infection, such as:

Prolonged diarrhea
Abdominal pain, cramping
Nausea, vomiting
Blood and mucus in your stool

Not everyone who has these symptoms will necessarily have testing done or be treated. An O&P is more likely to be ordered when you:

Have severe symptoms, dehydration, electrolyte imbalance, and/or other complications
Are very young, elderly, or have a weakened immune system
Have prolonged signs and symptoms and/or infections that do not resolve without treatment
Have recently drunk stream or lake water
Have been exposed to someone who has a parasitic infection (like a family member)

Precautions:

Warm stools are best for detecting Ova or

parasites. Do not refrigerate the specimen.

Because of cyclic life cycle of parasites, three

separate random stool specimens are

recommended for examination.

Advise patients the following for at least 48 hours before stool collection:

Avoid mineral oils.
Antibiotics such as tetracyclines.
Antidiarrheal medications that are not absorbent.
Avoid antimalarial drugs.
The patient should not have a barium ingestion test before the stool test.
If there is blood or mucus, that should be included in the stool. Because most pathogens are found in this substance.

Examine feces before giving antibiotics or other drugs.

Semi formed feces should be examined within 60 minutes after collection.
Liquid feces should be examined within the first 30 minutes.
Solid stool should be examined within the first hour of collection.
In the case of cases of constipation, use a non-residual purgative the night before stool collection.

Preservatives of Stool:

The preservatives for the wet preparation are:
10% saline formalin for wet preparation. This is the best preservative since it kills bacteria and preserves

protozoa and helminths.

Sodium formalin acetate.
iodine formalin. This is a good preservative for stool collection.
For staining use polyvinyl alcohol.
Avoid preservatives for stool culture.
Usually, three parts of the preservatives and one part of the stool.

Interfering factors:

Medications that irritate the gastric mucosa such as non-steroidal anti-inflammatory medicines (NSAIDs), anticoagulants, colchicine, corticosteroids, phenylbutazone, and iron preparations can cause positive results for occult blood
High doses of vitamin C (more than 250 mg per day) can cause false negative occult blood
Dietary intake of high in red meat, certain vegetables (radish, turnips, cauliflower, broccoli), and fruits (bananas, apples, cantaloupe) can cause false-positive results for occult blood
Constipated stools may not show any trypsin activity due to prolonged exposure to intestinal bacteria

Pre analytical errors:

specimen contaminated with urine, residual soap, or disinfectants.

Specimens recewed in grossly leaking transport containers,

Diapers, dry specimens.

specimens submitted in fixative or additives.

Corrective action:

Use The spoon built into the vial cap and transfer small samples from areas that appear bloody, slimy, or watery
continue adding samples until the liquid level in the vial reaches the red fill line, Avoid over or under filling
Mix specimen in the solution using the spoon provided.
Recap the vial, making sure the lid is tight, Shake the vial until the contents are well mixed.

Post analytical errors:

Incorrect test result
Improper manual data entry
Delay in test result

Reference range:

No ova or parasites seen