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Parasites in urine

Parasites in urine
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Fernando Martínez Sáez
Medically reviewed by our Medical staff

Last update: 28-09-2021

How else can it be called?

  • Trichomonas in urine

  • ICD-10: R82.5

Why parasites can be present in urine?

The presence of parasites in a urine test is useful for the diagnosis of UTI (Urinary Tract Infection) and infection of the male or female genital tract.

The most common parasites seen in a urine test are:

  • Trichomonas vaginalis: It is the most common parasite present in the urine and the cause of a disease called trichomoniasis.
  • Schistosoma haematobium: The ova of this bladder parasite may appear in the urine and it is the flatworm related to the schistosomiasis disease.
  • Enterobius vermicularis: It is an intestinal parasite that may appear in the urine sample by fecal contamination. It may appear ova of the parasite in the urine.

Sometimes, the presence of parasites and ova in the urine is a consequence of fecal or vaginal contamination of the urine specimen.

Why is this test performed?

The test is performed because it may help in the diagnosis of trichomoniasis, an infection of the male or female genital tract.

Trichomonas vaginalis is a sexually transmitted parasite associated primarily with vaginal inflammation in females and infection of the male urethra and prostate in males.

The test is also useful if the ova of parasite Schistosoma haematobium is detected because it helps to confirm the diagnosis of schistosomiasis, an infection that causes acute and chronic inflammation of the urinary and gastrointestinal tract. For the detection of this parasite, it is better to collect the urine sample in the evening.

How is the test performed?

To study the presence of parasites in the urine, it is necessary to obtain previously the urinary sediment.

For this matter, the urine sample should be placed at rest for some hours waiting for the different elements of the urine (white and red blood cells, yeast, crystals, etc.) precipitate to the bottom. As this process is very slow, the urine is centrifuged for about 5 minutes at 1500 or 2000 revolutions per second to obtain a sample of the sediment in less time.

The trichomonas has a pear shape with an undulating membrane. The trichomonas is often motile under the microscope and it may be recognized by the flagella that provides its rapid darting movement. When not moving, the trichomonas is more difficult to identify and may resemble a WBC (White Blood Cell), or a RTE (Renal Tubular Epithelial) cell.

Schistosoma eggs are around 60 and 160 micrometers long and are transparent with a prominent lateral spine near the posterior end.

Enterobius vermicularis eggs, under the microscope, have an oval shape with a flat edge. The larvae may be visible inside the egg.

Which does an abnormal result mean?

Trichomonas is usually reported as rare, few, moderate, or many per HPF (high-power-field).

If there is a big amount of trichomonas (Trichomonas vaginalis) detected under the microscope, it is usually a sign of trichomoniasis.

The trichomoniasis in females is the underlying cause of:

In males, trichomoniasis is often asymptomatic but they usually transmit the disease to their sexual partners.

If there is Schistosoma haematobium ova in the urine sample it is usually a sign of schistosomiasis.

Medically reviewed by our Medical staff on 28-09-2021


  • Essentials of Medical Laboratory Practice. Constance L. Lieseke, Elizabeth A. Zeibig. 2012. ISBN: 978-0-8036-1899-2 Pag: 446.
  • Urianalysis and Body Fluids. 5th edition. Susan King Strasinger. Marjorie Schaub Di Lorenzo. 2008. ISBN 978-0-8036-1697-4 Pag 100

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