Explanation

Ureaplasma parvum PCR (urine): what is measured?

Ureaplasma parvum is a small bacterium without a cell wall that is present in the genital organs of many healthy people without causing symptoms (carriage); in women it is the most common bacterium of this group. In adults, the bacterium is usually transmitted through sex, but it is not counted among the STIs. There is no good evidence that Ureaplasma parvum causes disease in adults. The PCR looks for genetic material of the bacterium in the first portion of urine and does not say whether the bacterium causes symptoms.

What can it detect?

Presence of Ureaplasma parvum in the urethra; this is usually carriage without symptoms

Result

What does the result mean?

Positive result

A positive result means that the bacterium is present. This is very common in people without symptoms and usually does not mean disease. According to a position statement of the European STI Guidelines Editorial Board (IUSTI, 2018), in most studies Ureaplasma parvum is even found more often in people without symptoms than in people with urethritis (inflammation of the urethra), and there is no good evidence of a link with inflammation or infertility. Treatment of a positive result is therefore not needed; the bacterium is also hard to get rid of permanently.

Negative result

A negative result means that the bacterium was not found. Because Ureaplasma parvum also occurs in healthy people and is not a proven cause of disease, a negative result has little meaning for your health. This result does not explain or rule out urethral symptoms; tests for chlamydia, gonorrhea and Mycoplasma genitalium, among others, are intended for that.

After an abnormal result

With a positive result, according to the European recommendation, no treatment or follow-up is needed, not even with symptoms. With symptoms, the GP looks for other causes, such as chlamydia, gonorrhea, Mycoplasma genitalium, trichomonas or, in women, bacterial vaginosis. Ureaplasma is not notifiable.

Reliability

How reliable is the test?

The PCR reliably detects the bacterium, but a positive result does not distinguish between carriage and an infection that causes symptoms. Ureaplasma parvum is not a proven cause of disease: the evidence that this bacterium causes urethritis or other symptoms is insufficient. As a result, a positive result says little, both in people without symptoms and in people with symptoms.

What can affect the result?

A positive result does not say whether the bacterium causes symptoms; many people without symptoms also carry the bacterium.
A link with urethritis in men has not been shown in a review of studies.
Treatment with antibiotics often does not remove the bacterium permanently.
If you urinated less than 1 hour before collecting the sample, or catch more than the first part of the stream, the sample is diluted and the test can miss an infection.

Preparation

Collect the urine when you have not passed urine for at least 1 hour.
Collect only the first part of the stream, not the middle part.

Who it is for

Who is the test useful for?

Useful for

The result usually does not explain symptoms, because the bacterium also occurs in many healthy people. Urethral symptoms more often fit chlamydia or gonorrhea, and, with symptoms lasting longer than 4 weeks, Mycoplasma genitalium. This test is not suitable for questions about pregnancy or fertility.

How common is it?

How common Ureaplasma parvum is in the Netherlands is not known, because it is not routinely tested for. In international studies using PCR, the bacterium was found in 20 to 89 percent of sexually active women who were not pregnant. In men, how common it is is not well known, but probably more common than Ureaplasma urealyticum.

Horner et al., European STI Guidelines Editorial Board (IUSTI), 2018

Drawbacks and risks

A positive result can lead to unnecessary treatment with antibiotics, with a chance of side effects and of resistance in this bacterium and in other bacteria, including those that cause real STIs.
A positive result can wrongly give the idea that you have an STI, leading to worry or tension in a relationship.

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