Explanation

Gonorrhea (Neisseria gonorrhoeae) PCR (urine): what is measured?

Gonorrhea (the clap) is an STI caused by the bacterium Neisseria gonorrhoeae. The PCR looks for genetic material of the bacterium in the first part of the urine; that is why you only collect the first part of the stream and, according to the kit instructions, do not urinate for at least 1 hour beforehand. In men, first-void urine is the first choice according to the LCI guideline (RIVM); in women, urine is less sensitive than a vaginal swab. The result only applies to the urethra, not to the throat or anus.

What can it detect?

A current gonorrhea infection of the urethra, even if it causes no symptoms
In men: a possible cause of pain when urinating and pus or mucus from the penis (the clap)

Result

What does the result mean?

Positive result

A positive result means that genetic material of the gonorrhea bacterium (Neisseria gonorrhoeae) was found, which fits a current infection. In men, gonorrhea of the urethra usually causes symptoms; in women and in the throat and anus, it often does not. Without treatment, gonorrhea can cause inflammation of the womb and fallopian tubes in women and inflammation of the epididymis or prostate in men; rarely, the bacterium spreads to the joints or blood. Gonorrhea can be treated with antibiotics, but the bacterium is increasingly becoming insensitive (resistant) to antibiotics.

Negative result

A negative result means that no gonorrhea was found in the urine. Without symptoms, Thuisarts advises testing from 2 weeks after the last risk contact. According to the LCI guideline (RIVM), it is not known exactly how soon the test becomes positive after infection; an infection without symptoms can last for months, so testing is useful up to 3 months after a risk contact. The result does not rule out gonorrhea in the throat or anus.

After an abnormal result

With a positive result, according to the guideline the GP preferably also has a culture done to see which antibiotics the bacterium is sensitive to, and usually treats with a single injection of an antibiotic; this goes together with testing for other STIs such as chlamydia, HIV and syphilis and warning sexual partners from the past six months. After treatment with the standard drug, a follow-up test is usually not needed. Gonorrhea is not notifiable for individual cases.

Reliability

How reliable is the test?

According to the LCI guideline (RIVM) and the multidisciplinary STI guideline, the PCR (NAAT) is the first choice for detecting gonorrhea: its sensitivity is higher than that of a culture, and the specificity on urine and vaginal material approaches 100 percent. In men, first-void urine is the recommended material; in women, a self-collected vaginal swab. A positive PCR says nothing about resistance; for that, the guideline advises a culture. Because the test detects genetic material, it can still be positive shortly after treatment.

What can affect the result?

Shortly after the risk contact, the test can miss an infection; without symptoms, the advice is to test from 2 weeks after the contact.
If you urinated less than 1 hour before collecting the sample, or collect more than the first part of the stream, the sample is diluted and the test can miss an infection.
Urine only tests the urethra; gonorrhea in the throat or anus usually causes no symptoms and is missed with urine. In women, urine is less sensitive than a vaginal swab, so an infection can be missed more often.
Up to about 2 weeks after treatment, the test can remain positive due to leftover genetic material.

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

Useful for men (and other people with a penis) with symptoms such as pain when urinating or pus or mucus from the penis, after sex without a condom with a new or changing partner, and if a sexual partner has gonorrhea. In men who have sex with men, gonorrhea is often also in the throat or anus; urine alone misses those infections. In women, a vaginal swab says more than urine, because urine is less sensitive in them.

How common is it?

In 2024, the GGD's Centers for Sexual Health found gonorrhea in 13,952 people; GPs made the diagnosis about 18,800 times in 2023. Gonorrhea is diagnosed much more often in men than in women, especially in men who have sex with men. The number of diagnoses has been rising for more than ten years.

RIVM (Centers for Sexual Health 2024, GPs 2023); LCI guideline on gonorrhea

Drawbacks and risks

Testing shortly after a risk contact can give false reassurance if no retest follows.
A negative urine result can give false reassurance if there was also a risk in the throat or anus.

Get tested