Also known as:GC Test; Gonorrhea NAAT or NAT
Formal name:Neisseria gonorrhoeae by Nucleic Acid Amplification Test (NAAT); Neisseria gonorrhoeae Culture; Neisseria gonorrhoeae Gram Stain; Neisseria gonorrhoeae DNA Probe
Related tests:Chlamydia Testing, HIV Antibody and HIV Antigen, Syphilis Tests, Herpes Testing, HPV Test, Trichomonas Testing
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Why Get Tested?
To screen for and diagnose a gonorrhea infection
When to Get Tested?
- For women, yearly testing recommended if you are sexually active and younger than age 25 or 25 or older and at increased risk for this sexually transmitted disease (STD); if you fall into one of these groups and are pregnant or considering pregnancy
- For men, yearly testing recommended if you are a man who has sex with men
- When you have symptoms of this STD, such as pain during urination, vaginal discharge or vaginal bleeding between menstrual periods (for women), or unusual discharge from the penis, pain during urination or painful, swollen testicles (for men)
- When a newborn has conjunctivitis
A swab or brush of cells or secretion from your vagina (for women) or from your penis (for men); for men or women, the initial portion of your urine stream (first-catch urine sample); sometimes a swab of cells or secretion from a non-genital area that may be infected
Test Preparation Needed?
Tell your healthcare provider about any use of antibiotics or, for women, douches or vaginal creams within 24 hours before testing vaginal samples since they may affect test results. Menstruation will not affect results. For a urine sample, you may be instructed to wait one to two hours after you last urinated before collecting the sample. Follow the instructions you are given.
How is it used?
Gonorrhea testing is used to screen for, diagnose, and verify successful treatment of infections caused by the bacteria Neisseria gonorrhoeae. Gonorrhea is a common sexually transmitted disease (STD) in the U.S. and can cause serious complications if not treated. Screening for, diagnosing, and treating gonorrhea is very important to prevent long-term complications and spread of the infection to others. (For more, see the "What is being tested?" section.) Photo source: National Institute of Allergy and Infectious Diseases (NIAID)
A definitive diagnosis is important because signs and symptoms of gonorrhea can resemble chlamydia and the two infections require different antibiotic treatment. Since the disorders have similar symptoms, healthcare practitioners often test for Neisseria gonorrhoeae and Chlamydia trachomatis, the bacteria that causes chlamydia, at the same time. Repeat testing is recommended to ensure that treatment has been effective. This is done about three months after a person has completed treatment.
Nucleic acid amplification test (NAAT) is the recommended method of testing for gonorrhea. NAAT is a molecular test that detects the genetic material (DNA) of Neisseria gonorrhoeae. It is generally more sensitive and specific than other gonorrhea tests and can be performed on a vaginal swab on women, or urine from both men and women, which eliminates the need for a pelvic exam in women.
Besides NAAT, another test to detect gonorrhea is a gonorrhea culture, which grows the bacteria. In men, a quick method that may be used in a clinic or healthcare provider's office is the gram stain, which allows the healthcare practitioner to look at a sample from the urethra for the presence of the bacteria using a microscope. While this method can diagnose gonorrhea, it is not sufficient to rule out an infection in asymptomatic men. This method is not reliable for samples from women since other bacteria normally found in the female genital tract will look the same under the microscope.
When is it ordered?
Because many infected people do not have any noticeable symptoms, a number of health organizations recommend regular screening for certain people.
All sexually active women younger than age 25 and sexually active women age 25 and older who are at increased risk should get yearly screening for gonorrhea, according to the U.S. Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG). The U.S. Preventive Services Task Force (USPSTF) and the American Academy of Pediatrics (AAP) also recommend routine screening for these women (the USPSTF says age 24 and younger).
Examples of risk factors for gonorrhea infection include:
- Previous gonorrhea infections, even if they were treated
- Having other STDs, especially HIV
- Having new or multiple sex partners
- Having a sex partner diagnosed with an STD
- Using condoms inconsistently
- Exchanging sex for money or drugs
- Using illegal drugs
- Living in a detention facility
For pregnant women, the CDC recommends screening women less than 25 years old and older women at risk for gonorrhea during the first trimester or first prenatal visit. Those who remain at risk should be retested during the third trimester. Those women diagnosed with gonorrhea should be treated and then retested within 3 months. (See Pregnancy & Prenatal Testing.)
The CDC recommends that men who have sex with men have gonorrhea screening at least annually. Health organizations do not recommend routine screening for sexually active, heterosexual males. Healthcare practitioners may recommend screening to their patients when, for example, there is a high number of cases (prevalence) of STDs in the community.
Gonorrhea testing may also be ordered when a person's sex partner has been diagnosed with gonorrhea or when a person has signs and symptoms of the infection.
For women, if symptoms occur, they may include:
- Bleeding between menstrual periods and after sexual intercourse
- Abdominal pain
- Painful intercourse
- Painful and/or frequent urination
- Abnormal vaginal discharge
Men may have no noticeable symptoms. If they do, they may include:
- A white, yellow or greenish discharge from the penis
- Pain or burning when urinating
- Pain, tenderness, and swelling of the testicles
Both men and women can get an infection in their rectum and may be tested when they have symptoms such as itching, inflammation, pain, discharge, and/or bleeding from the rectum. Testing for both chlamydia and gonorrhea may be done when a newborn has symptoms of conjunctivitis, such as redness and swelling of the eye, and discharge.
Women or men treated for gonorrhea should be retested three months after their treatment.
What does the test result mean?
A positive test indicates an active gonorrhea infection that requires treatment with a course of antibiotics.
A negative test means only that there is no evidence of infection at the time of the test. It is important for those who are at increased risk of infection to have screening tests performed on a annual basis to check for possible infection.
If you are infected, your sexual partner(s) should also be tested and treated as well.
Is there anything else I should know?
The Centers for Disease Control and Prevention (CDC) recommends the NAAT testing method for gonorrhea, except in cases of child sexual abuse in boys or rectal and oral infections in preteen girls. In these cases, culture is recommended.
If you are infected, your risk of contracting other sexually transmitted diseases, including HIV, is increased.
Molecular tests are only FDA-approved for use with urine samples or samples from genital sites such as the vagina and penis; they have not been FDA-approved for performance with ocular (eye), pharyngeal (throat), or rectal samples. Individual laboratories may perform molecular testing on these samples, but they are required to validate the methods themselves.
What is being tested?
Gonorrhea is a common bacterial sexually transmitted disease (STD) that can cause serious complications if not detected and treated. Gonorrhea testing identifies if the bacteria Neisseria gonorrhoeae is the cause of a person's infection. Screening for, diagnosing, and treating gonorrhea is very important in preventing long-term complications and spread of the infection to others.
The Centers for Disease Control and Prevention (CDC) estimates that more than 820,000 people in the U.S. get new gonorrheal infections each year, but only about half of these infections get reported to the CDC. In the U.S., the highest reported rates of infection are among sexually active teenagers, young adults, and African Americans.
Gonorrhea is generally spread through sexual contact (oral, vaginal, or anal) with an infected partner. Risk factors include having multiple sex partners, coinfection or previous infection with another STD, and not using a condom correctly and consistently.
While some men with gonorrhea will notice symptoms, most women do not or will mistake gonorrhea symptoms for a bladder or other vaginal infection. For men, symptoms usually appear within 2 to 5 days of infection but can take up to 30 days. Women who experience symptoms usually do so within 10 days of infection. Signs and symptoms of gonorrhea are similar to and can be confused with those caused by another STD, chlamydia, so tests for these infections are often done at the same time. (For more, see "The Test" tab.)
Gonorrhea can usually be treated with a course of antibiotics. If not diagnosed and treated, gonorrhea can cause serious complications.
In women, untreated gonorrhea infections may lead to pelvic inflammatory disease (PID), which can develop from several days to several months after infection and cause complications such as:
- Long-term (chronic) pelvic pain
- An increased risk of tubal (ectopic) pregnancy, which can be fatal
Pregnant women who are infected may experience heavy bleeding before delivery and premature rupture of the membranes and/or have babies with low birth weights. They may pass the infection to their babies during childbirth.
In men, untreated gonorrhea can cause complications such as:
- Inflammation of the prostate gland
- Scarring of the urethra, possible narrowing or closing of the urethra
Untreated gonorrhea may also spread to the blood (septicemia) or joints, progressing to a serious condition called disseminated gonococcal infection (DGI). DGI symptoms include fever, multiple skin lesions, painful swelling of joints (gonococcal arthritis), infection of the inner lining of the heart, and inflammation of the membrane covering the brain and spinal cord (meningitis). Symptoms of DGI in infants born to infected mothers include those associated with arthritis, meningitis and sepsis, a severe, life-threatening condition.
DGI can be successfully treated using antibiotics similar to those used for treating uncomplicated gonorrhea. However, treatment-resistant gonorrhea is a growing threat. CDC guidelines currently recommend dual therapy with ceftriaxone and azithromycin to treat all uncomplicated gonococcal infections among adults and adolescents in the United States. If a person's symptoms do not resolve after treatment, a healthcare practitioner may need to perform additional "tests for cure" and susceptibility testing may be indicated.
Currently, there is no reliable technology that can determine antibiotic susceptibility without first culturing Neisseria gonorrhoeae. Laboratories must be able to perform essential culture techniques that grow the bacteria. However, the widespread use of the nucleic acid amplification test (NAAT) for gonorrhea has made this increasingly difficult.
How is the sample collected for testing?
For women, vaginal swabs may be used to collect a sample for genital gonorrhea testing. A healthcare practitioner may use a swab or small brush to collect a sample of cells or secretion from the vagina during a pelvic examination. Sometimes, a vaginal sample is collected by the woman who is undergoing testing (self-collection).
For men, a healthcare practitioner may use a swab to collect a sample from the urethra, the tube within the penis that allows urine to flow from the bladder.
Urine samples can be used to test both men and women. As you begin to urinate, collect the initial portion of your urine stream (first-catch) in a container provided by the healthcare practitioner or laboratory.
Sometimes, a healthcare practitioner may use a swab or brush to collect a sample of cells or secretion from other areas that may be infected, such as the rectum or throat.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
Tell the healthcare practitioner about any use of antibiotics or, if you are a woman, douches or vaginal creams. You may be asked to avoid using these within 24 hours before testing vaginal samples since they may affect test results. Menstruation will not affect results. You may be instructed to wait one to two hours after you last urinated before collecting the urine sample. Follow any instructions you are given.
- How long does it take to get results?
It depends on where the lab testing is done and the method used to diagnose the infection. Nucleic acid amplification (NAAT) methods can give results in one to a few days. Cultures take longer and results are typically reported in three to five days. For male patients, gram stains can be done rapidly during a clinic or office visit, but results are not as reliable as NAAT.
- Where can I get tested?
Visit the healthfinder.gov webpage Get Tested for Chlamydia and Gonorrhea to find out where you can get tested. You can input your zip code and find a local testing site.
- How can gonorrhea be prevented?
The most reliable ways to avoid infection with gonorrhea or any sexually transmitted disease are to abstain from oral, vaginal, and anal sex or to be in a long-term, mutually monogamous relationship with an uninfected partner. People who are sexually active should correctly and consistently use condoms to reduce the risk of infection with gonorrhea and other STDs.
- How is gonorrhea treated?
The U.S. Centers for Disease Control and Prevention (CDC) currently recommends that an infected person be prescribed two drugs, ceftriaxone and azithromycin. These two drugs are taken at the same time to lessen the chance that the gonorrhea infection will be resistant to treatment. If the person's symptoms continue, then the healthcare practitioner may need to perform additional "tests for cure" and susceptibility testing to guide further treatment. The infected person should refrain from having sex until treatment has been completed and should be re-tested three months after treatment.
- If I get treated, can I get gonorrhea again?
Yes. Even though treatment will cure your infection, you can get it again if you are exposed again. In fact, reinfection is common, according to the CDC.
- Should I tell my partner that I have gonorrhea?
Yes, you should tell your sexual partner(s) that you have gonorrhea so that they can get tested and treated.
© 2017 American Association for Clinical Chemistry, republished from Lab Tests Online.*
Descriptions of clinical laboratory tests were originally prepared for use on Lab Tests Online, an award-winning patient education website on clinical laboratory testing. Lab Tests Online is produced by the American Association for Clinical Chemistry (AACC), a global scientific and medical professional organization dedicated to clinical laboratory science and its application to healthcare. The Lab Tests Online website is developed in collaboration with other laboratory professional societies and is funded in part through corporate sponsorships.