Gonorrhea, caused by the bacterium Neisseria gonorrhoeae, is one of the most frequently reported sexually transmitted infections (STIs) globally. A simple urine test can detect this infection, and it has become a standard and highly accurate method for screening and diagnosing genital gonorrhea. This diagnostic method is not a traditional urinalysis used for kidney function; instead, it involves a specialized molecular technique performed on the collected sample.
How Urine Samples Detect Gonorrhea
Urine testing for gonorrhea relies on Nucleic Acid Amplification Testing (NAAT). This sophisticated laboratory process does not rely on growing the bacteria in a culture dish. Instead, NAAT searches directly for the specific genetic material (DNA or RNA) of Neisseria gonorrhoeae, even if only small quantities are present.
The process works by amplifying the bacterial genetic sequences millions of times, making them easily detectable. This molecular approach is fast, highly sensitive, and non-invasive. The test requires a “first-catch” urine sample, as this initial stream is most likely to contain bacteria shed from the urethra or cervix. For genital infections, urine NAATs typically achieve sensitivity and specificity rates of 95% or higher.
Understanding the Limitations of Urine Testing
While urine-based NAAT is highly effective for detecting genital infections, it has significant limitations concerning other potential infection sites. Gonorrhea can infect any mucous membrane exposed during sexual contact, including the pharynx (throat) and the rectum. A urine sample can only detect bacteria that have colonized the urogenital tract (urethra, cervix, or vagina).
If the infection is solely in the throat or rectum, relying only on a urine test will result in a false negative. This is a concern because extra-genital infections are often asymptomatic, meaning the person shows no signs of infection but can still transmit the bacterium. To ensure comprehensive screening for individuals who engage in oral or anal sex, swabs from the pharynx and rectum must be collected in addition to the urine sample.
Treatment and Follow-Up After Diagnosis
Once a positive result for gonorrhea is confirmed, treatment focuses on eliminating the bacterium and preventing its spread. The standard treatment for uncomplicated urogenital or rectal gonorrhea is a single, higher-dose injection of the antibiotic ceftriaxone. If a concurrent chlamydial infection has not been ruled out, a healthcare provider may also prescribe an oral antibiotic like doxycycline.
It is important to complete the full course of medication to ensure the infection is fully eradicated and to minimize the risk of antibiotic resistance. Additionally, a person diagnosed with gonorrhea should notify all recent sexual partners so they can be tested and treated promptly.
A “test of cure” (TOC), which confirms the treatment worked, is generally not needed for uncomplicated urogenital or rectal infections unless symptoms persist. However, a TOC is specifically recommended for pharyngeal infections 7 to 14 days after treatment, as the bacteria are more difficult to eradicate from this site. Patients are also advised to be retested approximately three months after treatment to check for potential reinfection.