How to test for chlamydia

Screening and diagnosis of chlamydia is relatively simple. There are a number of diagnostic tests for chlamydia, including nucleic acid amplification tests (NAATs), cell culture, and others. Nucleic acid amplification tests (NAATs) are the most sensitive tests, and can be performed on easily obtainable specimens such as vaginal swabs (either clinician- or patient-collected) or urine ¹. Laws and regulations in all states require that people diagnosed with chlamydia be reported to public health authorities by clinicians, laboratories, or both. Chlamydia tests include:

• A urine test. A sample of your urine is analyzed in the laboratory for presence of chlamydia infection.
• A swab. For women, your doctor takes a swab of the discharge from your cervix for culture or antigen testing for chlamydia. This can be done during a routine Pap test. Some women prefer to swab their vaginas themselves, which has been shown to be as diagnostic as doctor-obtained swabs.

For men, your doctor inserts a slim swab into the end of your penis to get a sample from the urethra. In some cases, your doctor will swab the anus.

Vaginal swabs, either patient- or clinician-collected, are the optimal specimen to screen for genital chlamydia using nucleic acid amplification tests (NAATs) in women; urine is the specimen of choice for men, and is an effective alternative specimen type for women ¹. Self-collected vaginal swab specimens perform at least as well as other approved specimens using NAATs ². In addition, patients may prefer self-collected vaginal swabs or urine-based screening to the more invasive endocervical or urethral swab specimens ³. Adolescent girls may be particularly good candidates for self-collected vaginal swab- or urine-based screening because pelvic exams are not indicated if they are asymptomatic.

Chlamydial culture can be used for rectal or pharyngeal specimens, but is not widely available. Nucleic acid amplification tests (NAATs) have demonstrated improved sensitivity and specificity compared with culture for the detection of Chlamydia trachomatis at non-genital sites ⁴. Most tests, including NAATs, are not FDA-cleared for use with rectal or pharyngeal swab specimens; however, NAATS have demonstrated improved sensitivity and specificity compared with culture for the detection of Chlamydia trachomatis at rectal sites ⁴ and however, some laboratories have met regulatory requirements and have validated NAAT testing on rectal and pharyngeal swab specimens.

If you’ve been treated for an initial chlamydia infection, you should be retested in about three months.

Chlamydia (Chlamydia trachomatis) is the most common sexually transmitted disease (STD) that can infect both men and women in the United States, with 1,708,569 cases reported in 2017 ⁵. Chlamydia can also be easily cured with antibiotics (e.g., doxycycline, azithromycin or levofloxacin). You might receive a one-time dose, or you might need to take the medication daily or multiple times a day for five to 10 days. In most cases, chlamydia infection resolves within one to two weeks. During that time, you should abstain from sex. Your sexual partner or partners also need treatment even if they have no signs or symptoms. Otherwise, the chlamydia infection can be passed back and forth between sexual partners.

Having chlamydia or having been treated for it in the past doesn’t prevent you from getting it again.

Chlamydia can cause serious, permanent damage to a woman’s reproductive system if left untreated. If you are a woman, untreated chlamydia can spread to your uterus and fallopian tubes (tubes that carry fertilized eggs from the ovaries to the uterus). This can cause pelvic inflammatory disease (PID). Pelvic inflammatory disease often has no symptoms, however some women may have abdominal and pelvic pain. Even if it doesn’t cause symptoms initially, pelvic inflammatory disease can cause permanent damage to your reproductive system. Pelvic inflammatory disease can lead to long-term pelvic pain, inability to get pregnant, and potentially deadly ectopic pregnancy (pregnancy that occurs outside the womb). Men rarely have health problems linked to chlamydia. Infection sometimes spreads to the tube that carries sperm from the testicles, causing pain and fever. Rarely, chlamydia can prevent a man from being able to have children.

Untreated chlamydia may also increase your chances of getting or giving HIV – the virus that causes AIDS.

The Centers for Disease Control and Prevention (CDC) recommends chlamydia screening for:

• Sexually active women age 25 or younger. The rate of chlamydia infection is highest in this group, so a yearly screening test is recommended. Even if you’ve been tested in the past year, get tested when you have a new sex partner.
• Pregnant women. You should be tested for chlamydia during your first prenatal exam. If you have a high risk of infection — from changing sex partners or because your regular partner might be infected — get tested again later in your pregnancy.
• Women and men at high risk. People who have multiple sex partners, who don’t always use a condom or men who have sex with men should consider frequent chlamydia screening. Other markers of high risk are current infection with another sexually transmitted infection and possible exposure to an STD through an infected partner.

Because chlamydia is usually asymptomatic, screening is necessary to identify most infections. Screening programs have been demonstrated to reduce rates of adverse complications in women ⁶. CDC recommends yearly chlamydia screening of all sexually active women younger than 25, as well as older women with risk factors such as new or multiple partners, or a sex partner who has a sexually transmitted infection ⁷. Pregnant women should be screened during their first prenatal care visit. Pregnant women under 25 or at increased risk for chlamydia (e.g., women who have a new or more than one sex partner) should be screened again in their third trimester ⁷. Women diagnosed with chlamydial infection should be retested approximately 3 months after treatment ⁷. Any woman who is sexually active should discuss her risk factors with a health care provider who can then determine if more frequent screening is necessary.

Routine screening is not recommended for men. However, the screening of sexually active young men should be considered in clinical settings with a high prevalence of chlamydia (e.g., adolescent clinics, correctional facilities, and STD clinics) when resources permit and do not hinder screening efforts in women ⁷.

Sexually active men who have sex with men who had insertive intercourse should be screened for urethral chlamydial infection and men who have sex with men who had receptive anal intercourse should be screened for rectal infection at least annually; screening for pharyngeal infection is not recommended.. More frequent chlamydia screening at 3-month intervals is indicated for men who have sex with men, including those with HIV infection, if risk behaviors persist or if they or their sexual partners have multiple partners ⁷.

At the initial HIV care visit, doctors should test all sexually active persons with HIV infection for chlamydia and perform testing at least annually during the course of HIV care. A patient’s health care provider might determine more frequent screening is necessary, based on the patient’s risk factors.

How does chlamydia spread?

You can get chlamydia by having vaginal, anal, or oral sex with someone who has chlamydia. If your sex partner is male you can still get chlamydia even if he does not ejaculate (cum).

If you’ve had chlamydia and were treated in the past, you can still get infected again. This can happen if you have unprotected sex with someone who has chlamydia.

If you are pregnant, you can give chlamydia to your baby during childbirth.

You are more likely to become infected with chlamydia if you have:

• Sex without using a condom
• Had multiple sexual partners
• Been infected with chlamydia before.

How do I know if I have chlamydia?

Chlamydia is known as a ‘silent’ infection because most infected people are asymptomatic and lack abnormal physical examination findings. So you may not realize that you have chlamydia. But even if you don’t have symptoms, you can still pass chlamydia infection to others.

Early-stage chlamydia infections often cause few or no signs and symptoms. Even when you have signs and symptoms, they’re often mild, making them easy to overlook.

If you do have symptoms, they may not appear until 1 to 3 weeks after you have sex with someone who has chlamydia.

Signs and symptoms of chlamydia trachomatis infection can include ⁸, ⁹, ¹⁰, ¹¹, ¹², ¹³:

• Painful urination (a burning sensation).
• Vaginal discharge in women
• Discharge from the penis in men
• Pain in the testicles in men.
• Painful sexual intercourse in women
• Irregular periods, bleeding between periods and after sex in women
• Testicular pain in men
• Lower abdominal pain
• Rectal pain, discharge, and bleeding for men and women who engage in anal sexual activity.
• Reactive arthritis in both men and women (pain and inflammation of the joints that develops from an infection).
• Lymphogranuloma venereum. Lymphogranuloma venereum causes painful and swollen lymph nodes (buboes), which can then break down into large ulcers. Lymphogranuloma venereum symptoms include:
  • Drainage through the skin from lymph nodes in the groin
  • Painful bowel movements
  • Small painless sore on the male genitals or in the female genital tract
  • Swelling and redness of the skin in the groin area
  • Swelling of the labia (in women)
  • Swollen groin lymph nodes on one or both sides; it may also affect lymph nodes around the rectum in people who have anal intercourse
  • Blood or pus from the rectum (blood in the stools)

Chlamydia symptoms in women include:

• An abnormal vaginal discharge
• A burning sensation when urinating
• Bleeding between menstrual periods and after sexual intercourse
• Abdominal pain
• Painful intercourse
• Painful and/or frequent urination

Chlamydia symptoms in men include:

• A discharge from their penis
• Pus or milky discharge from the penis
• A burning sensation when urinating
• Painful and/or frequent urination
• Pain and swelling in one or both testicles (although this is less common).

Men and women can also get infected with chlamydia in their rectum. This happens either by having receptive anal sex, or by spread from another infected site (such as the vagina). While these infections often cause no symptoms, they can cause:

• Rectal pain;
• Discharge;
• Bleeding.

You should be examined by your doctor if you notice any of these symptoms or if your partner has an sexually transmitted disease (STD) or symptoms of an STD. STD symptoms can include an unusual sore, a smelly discharge, burning when urinating, or bleeding between periods.

Who should be tested for chlamydia?

Sexually active people can get chlamydia through vaginal, anal, or oral sex without a condom with a partner who has chlamydia. You should go to your doctor or a STD clinic for a test if you have symptoms of chlamydia or if you have a partner who has an STD. Pregnant women should get a test when they go to their first prenatal visit.

People at higher risk should get checked for chlamydia every year:

• Sexually active women 25 and younger
• Older women who have new or multiple sex partners or a sex partner who has an STD
• Men who have sex with men (MSM)

Sexually active young people are at a higher risk of getting chlamydia. This is due to behaviors and biological factors common among young people ¹⁴. Gay and bisexual men are also at risk since chlamydia can spread through oral and anal sex.

If you are sexually active, have an honest and open talk with your healthcare provider. Ask them if you should get tested for chlamydia or other STDs. Gay or bisexual men and pregnant people should also get tested for chlamydia.

STD clinic near you

Although it may be embarrassing, if you are sexually active, getting tested for STDs is one of the most important things you can do to protect your health. Make sure you have an open and honest conversation about your sexual history and STD testing with your doctor and ask whether you should be tested for STDs. If you are not comfortable talking with your regular health care provider about STDs, there are many clinics that provide confidential and free or low-cost testing. Below or following this link to find an STD testing center near you https://www.cdc.gov/std/prevention/screeningreccs.htm

How long does it take to get my chlamydia test results?

This will depend 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 5 to 7 days.

Is there a cure for chlamydia?

Yes, antibiotics will cure chlamydia infection. You may get a one-time dose of the antibiotics, or you may need to take medicine every day for 7 days. It is important to take all the medicine that your doctor prescribed for you to cure your infection. When taken properly antibiotic will stop chlamydia infection and could decrease your chances of having problems later (see Chlamydia complications below). Antibiotics cannot repair any permanent damage that chlamydia has caused.

To prevent spreading chlamydia to your partner, you should not have sex until the chlamydia infection has cleared up. If you got a one-time dose of antibiotics, you should wait 7 days after taking the medicine to have sex again. If you have to take medicine every day for 7 days, you should not have sex again until you have finished taking all of the doses of your medicine.

It is common to get a repeat chlamydia infection, so you need to get tested again about three months after your treatment, even if your sex partner(s) receives treatment.

How is chlamydia treated?

Chlamydia can be easily cured with antibiotics. HIV-positive persons with chlamydia should receive the same treatment as those who are HIV-negative.

Recommended antibiotics for chlamydial infection among adolescents and adults ¹⁵:

• Doxycycline 100 mg orally 2 times/day for 7 days

Alternative Regimens

• Azithromycin 1 g orally in a single dose
• OR
• Levofloxacin 500 mg orally once daily for 7 days

Treatment of chlamydial infections during pregnancy

The recommended regimen for the treatment of chlamydial infections in pregnant women is azithromycin 1 gram orally in a single dose; amoxicillin is the alternative medication ⁸. Doxycycline and levofloxacin are not recommended for the treatment of chlamydial infections in pregnancy ⁸. Erythromycin is no longer recommended for the treatment of chlamydia during pregnancy due to gastrointestinal side effects that make adherence challenging for the mother during pregnancy. All pregnant women treated for chlamydial infection should have a test-of-cure performed 4 weeks after completing therapy and all should be retested 3 months after treatment for reinfection ⁸.

Adults with oropharyngeal chlamydial infections

The clinical significance of oropharyngeal Chlamydia trachomatis infection remains unclear, and routine screening for oropharyngeal Chlamydia trachomatis infection is not recommended. Nevertheless, since oropharyngeal C. trachomatis can be transmitted to genital sites of sex partners ¹⁶, ¹⁷, detection of Chlamydia trachomatis from an oropharyngeal sample warrants the same treatment as with urogenital chlamydial infection: doxycycline 100 mg orally twice daily for 7 days as the preferred regimen for nonpregnant adults and azithromycin 1 gram single dose orally preferred for pregnant persons ⁸.

Treatment for lymphogranuloma venereum

The recommended treatment for Chlamydia trachomatis infections caused by lymphogranuloma venereum strains is oral doxycycline 100 mg twice daily for 21 days; note this treatment is significantly longer than the 7-day treatment for non-lymphogranuloma venereum chlamydia strains ⁸. The alternative lymphogranuloma venereum treatment regimens include oral azithromycin 1 gram weekly for 3 weeks or oral erythromycin base 500 mg four times daily for 21 days ¹⁸. Since practical laboratory diagnostic methods are not available for making a timely diagnosis of lymphogranuloma venereum, the indication to provide lymphogranuloma venereum treatment (doxycycline 100 mg twice daily for 21 days) should be based on epidemiologic information, compatible clinical finding, and a positive Chlamydia trachomatis NAAT at the symptomatic anatomic site ¹⁸. In addition, empiric therapy for lymphogranuloma venereum is indicated for persons in whom (1) symptoms or signs of proctocolitis (e.g. bloody discharge, tenesmus, or ulceration), (2) those with severe inguinal lymphadenopathy with bubo formation, especially if the individual reports recently having a genital ulcer, and (3) persons with a genital ulcer and other causes for the genital ulcer have been excluded ¹⁸.

Management of sex partners

For persons diagnosed with urogenital chlamydial infection, all sex partners with whom they had sexual contact during the 60 days preceding the onset of symptoms or chlamydia diagnosis should be referred for evaluation, testing, and presumptive treatment of chlamydia ⁸. If no sex contacts have occurred in the 60 days before the diagnosis of chlamydia or onset of symptoms, then the most recent sex partner prior to that 60-day period should be evaluated and treated ⁸. All sex contacts should have testing for STDs as part of the evaluation process. The sex contacts should receive presumptive treatment for chlamydia without waiting for their STD test results to ensure the treatment does not depend on an additional follow-up visit. The empiric treatment for nonpregnant sex contacts is oral doxycycline 100 mg twice daily for 7 days and for pregnant contacts it is azithromycin 1 gram orally as a single dose. The purpose of performing an evaluation for the contact, even if they will receive presumptive treatment, is to perform counseling and screening for other STDs, which may require treatment. For neonates or infants diagnosed with chlamydial infection, it is important that mothers and their sex partners undergo diagnostic evaluation and receive empiric treatment for chlamydial infection.

Use of expedited partner therapy

Certain situations may arise in which sexual contacts are unable or unwilling to present for evaluation, testing, and treatment. In this scenario, there may be an option to provide expedited partner therapy (EPT)—a process whereby the patient diagnosed with chlamydia delivers treatment (or a prescription for treatment)—to the recent sex partner, without a medical provider examining the partner. This strategy has been demonstrated to decrease the rate of recurrent or persistent chlamydia infection ¹⁹, ²⁰, ²¹. There are concerns regarding the use of expedited partner therapy for men who have sex with men, since, ideally, these individuals would get tested for other STDs, such as syphilis and HIV, during a clinic visit ⁸. The use of expedited partner therapy for men who have sex with men should therefore be performed on a shared-decision basis. Finally, expedited partner therapy is not legal in all states; the CDC maintains an updated information page (Legal Status of Expedited Partner Therapy) that identifies the legal status of expedited partner therapy in each state in the United States.

Infants born to mothers with chlamydial infection

When neonatal chlamydial infection occurs, it results from neonatal contact with a chlamydia-infected cervix during the birth process. Neonatal chlamydial infection most often manifests as conjunctivitis (ophthalmia neonatorum) that develops 5 to 12 days after birth or as a subacute, afebrile pneumonia with onset at ages 1 to 3 months. The erythromycin eye ointment that is routinely given to neonates at birth to prevent neonatal gonococcal ophthalmia neonatorum does not prevent neonatal chlamydial eye infection ⁸. The most effective strategy for preventing perinatal chlamydia transmission is to screen pregnant women for chlamydial infection and promptly treat those women who test positive. Prophylactic antibiotic treatment is not recommended for infants who are born to mothers at high risk for chlamydia or who have untreated chlamydia. In this situation, the recommended approach is to monitor the infant for signs and symptoms of chlamydial infection and promptly evaluate and treat any documented infection in the neonate ⁸.

Neonates with ophthalmia neonatorum

The recommended treatment regimen for the neonate with ophthalmia neonatorum is a 14-day course of oral erythromycin base or erythromycin ethylsuccinate ⁸. Data on oral azithromycin for the treatment of neonatal chlamydial infection are limited, but a small study suggested a short 3-day course of azithromycin may be effective.[93] The use of topical erythromycin alone is not effective for ophthalmia neonatorum, and it is not recommended for use in combination with oral antibiotics ⁸. The use of a recommended or alternative therapy has an efficacy of only approximately 80% and some infants require treatment with a second course of antibiotics. Treatment with oral erythromycin or oral azithromycin in infants during the first 6 weeks of life has been associated with an increased risk of infantile hypertrophic pyloric stenosis ²², ²³. Thus, all infants with chlamydial ophthalmia neonatorum should have close follow-up to determine the treatment response and to evaluate signs and symptoms of infantile hypertrophic pyloric stenosis ²².

Infant pneumonia

For infants with pneumonia caused by Chlamydia trachomatis, the recommended treatment is a 14-day regimen of oral erythromycin base or erythromycin ethylsuccinate; the alternative regimen is a 3-day course of oral azithromycin ⁸. The treatment for chlamydial pneumonia in neonates often occurs empirically, based on the infant’s chest radiographic findings, the age of the infant, and the mother’s epidemiologic risk for chlamydial infection ⁸. In situations when presumptive therapy is used in a situation with a high degree of suspicion of chlamydial infection, and there is considerable concern that follow-up will not occur, the 3-day azithromycin alternative regimen can be used ⁸.

Chlamydial infections in infants and children

The treatment of infants and children with chlamydia is stratified into three groups: (1) younger than 8 years of age and weight less than 45 kg, (2) younger than 8 years of age and weight 45 kg or greater, and (3) age 8 or older ⁸. In infants and children who weigh less than 45 kg, the preferred treatment of chlamydial infections is a 14-day course of oral erythromycin base or oral erythromycin ethylsuccinate ⁸. For children younger than 8 years of age and weighing 45 kg or greater, the recommended regimen is single-dose oral azithromycin. Children older than 8 years of age should be treated with single-dose oral azithromycin or a 7-day course of oral doxycycline ⁸. A follow-up visit with chlamydia test-of-cure is recommended approximately 4 weeks after completion of treatment to evaluate for treatment effectiveness ⁸.

When can I have sex again after my chlamydia treatment?

You should not have sex again until you and your sex partner(s) complete treatment. If given a single dose of medicine, you should wait seven days after taking the medicine before having sex. If given medicine to take for seven days, wait until you finish all the doses before having sex.

If you’ve had chlamydia and took medicine in the past, you can still get it again. This can happen if you have sex without a condom with a person who has chlamydia.

What happens if I don’t get treated for chlamydia?

The initial damage that chlamydia causes often goes unnoticed. However, chlamydia can lead to serious health problems.

In women, untreated chlamydia can cause pelvic inflammatory disease (PID). Some of the complications of pelvic inflammatory disease are:

• Formation of scar tissue that blocks fallopian tubes;
• Ectopic pregnancy (pregnancy outside the womb);
• Infertility (not being able to get pregnant); and
• Long-term pelvic/abdominal pain.

Men rarely have health problems from chlamydia. The infection can cause a fever and pain in the tubes attached to the testicles. This can, in rare cases, lead to infertility.

Untreated chlamydia may also increase your chances of getting or giving HIV.

I’m pregnant. How does chlamydia affect my baby?

If you are pregnant and have chlamydia, you can pass the infection to your baby during delivery. This could cause an eye infection or pneumonia in your newborn. Having chlamydia may also make it more likely to deliver your baby too early.

If you are pregnant, you should get tested for chlamydia at your first prenatal visit. Testing and treatment are the best ways to prevent health problems.

How can I reduce my risk of getting chlamydia?

The only way to avoid STDs is to not have vaginal, anal, or oral sex.

If you are sexually active, you can do the following things to lower your chances of getting chlamydia:

• Be in a long-term mutually monogamous relationship with a partner who has been tested and has negative STD test results;
• Use latex condoms the right way every time you have sex.

Over the counter chlamydia test or at home chlamydia test

Nucleic acid amplification tests (NAATs) amplify nucleic acid sequences (either DNA or RNA) that are specific for the organism being detected. Similar to other nonculture tests, nucleic acid amplification tests (NAATs) can detect replicating or nonviable organisms. Multiple commercially available NAATs are FDA-cleared as diagnostic tests for Chlamydia trachomatis on urine specimens from men and women, urethral secretions in men, and endocervical swabs in women; some tests are cleared for vaginal swabs ⁸. In addition, in May 2019, the United States Food and Drug Administration (FDA) cleared two NAATs for diagnostic testing of chlamydia at extragenital sites (pharynx and rectum); the two tests are the Aptima Combo 2 Assay and the Xpert CT/NG ²⁴. For chlamydia testing in men, NAATs are highly sensitive for detecting Chlamydia trachomatis in either urethral secretions or a first-catch urine specimen, but most experts prefer using first-catch urine samples ⁸. For women, vaginal swabs are preferred over urine samples since they are more sensitive than urine samples ⁸. Several studies have shown that self-collected vaginal swabs are preferred by women and perform equal to or better than clinician-collected vaginal swabs ²⁵, ²⁶. In addition, in men and women, self-collected rectal swabs for NAAT have also performed well ²⁷. Nucleic acid amplification tests do not distinguish non-lymphogranuloma venereum (non-LGV) from lymphogranuloma venereum (LGV) strains.

Because NAATs are so sensitive, efforts are warranted to prevent contamination of specimens in the clinic or spread of environmental amplicon in the laboratory.

Specimen Collection Method

Chlamydia trachomatis and Neisseria gonorrhoeae testing in men

• Nucleic acid amplification tests (NAATs) are the recommended test method.
• A first catch urine is the recommended sample type and is equivalent to a urethral swab in detecting infection.
• A urethral swab specimen for Neisseria gonorrhoeae culture should be obtained and evaluated for antibiotic susceptibility in patients who have received Centers for Disease Control and Prevention (CDC)-recommended an antimicrobial regimen as treatment, and subsequently had a positive Neisseria gonorrhoeae test result (positive NAAT ≥7 days after treatment), and did not engage in sexual activity after treatment.

Chlamydia trachomatis and Neisseria gonorrhoeae testing in women

• Nucleic acid amplification tests (NAATs) are the recommended test method.
• A self- or clinician-collected vaginal swab is the recommended sample type. Self-collected vaginal swab specimens are an option for screening women when a pelvic exam is not otherwise indicated.
• An endocervical swab is acceptable when a pelvic examination is indicated.
• A first catch urine specimen is acceptable but might detect up to 10% fewer infections when compared with vaginal and endocervical swab samples.
• An endocervical swab specimen for Neisseria gonorrhoeae culture should be obtained and evaluated for antibiotic susceptibility in patients that have received
• Centers for Disease Control and Prevention (CDC)-recommended antimicrobial regimen as treatment, and subsequently had a positive Neisseria gonorrhoeae test result (positive NAAT ≥7 days after treatment), and did not engage in sexual activity after treatment.

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae infections in the rectum and oropharynx

• Nucleic acid amplification tests (NAATs) are the recommended test method for rectal and oropharyngeal specimens.
• Laboratories must be in compliance with Clinical Laboratory Improvement Amendments (CLIA) for test modifications since these tests have not been cleared by the FDA for these specimen types.
• Commensal Neisseria species commonly found in the oropharynx might cause false positive reactions in some NAATs, and further testing might be required for accuracy.
• A rectal or oropharyngeal swab specimen for Neisseria gonorrhoeae culture should be obtained and evaluated for antibiotic susceptibility in patients who have received Centers for Disease Control and Prevention (CDC)-recommended antimicrobial regimen as treatment, had a subsequent positive Neisseria gonorrhoeae test result (positive NAAT ≥7 days after treatment), and did not engage in sexual activity after treatment.

Point-of-Care NAAT Testing

In March 2021, the FDA approved the first point-of-care nucleic acid amplification test (NAAT) (Binx Health IO CT/NG Assay) for the diagnosis of urogenital chlamydia and gonorrhea ²⁸. This point-of-care test can be run on vaginal swabs obtained from women or on urine samples collected from men ²⁸. This assay can provide a result in approximately 30 minutes ²⁸. In a cross-sectional study, investigators evaluated this point-of-care NAAT for the diagnosis of chlamydia and gonorrhea using vaginal swabs obtained from 1,523 women and urine samples collected from 922 men ²⁹. For chlamydia, the sensitivity estimates were 96.1% in women and 92.5% in men; the specificity estimates were 99.1% for women and 99.3% for men ²⁹. In addition, the investigators found that self-obtained vaginal swabs in women performed equivalent to clinician-collected vaginal swabs ²⁹.

Non-amplification molecular tests

Molecular tests that do not use nucleic acid amplification encompass a variety of antigen detection and nucleic acid hybridization methods. These tests include enzyme-immunoassays (EIA), direct fluorescent antibody tests (DFA), and nucleic acid hybridization tests—a distinct non-NAAT methodology that can detect C. trachomatis-specific DNA or RNA sequences in ribosomal RNA, genomic DNA, or plasmid DNA. All have a significantly lower sensitivity (range 50% to 75%) than NAATs ³⁰. These non-amplification tests are rarely used in clinical practice, and they are classified as not recommended by the Centers for Disease Control and Prevention (CDC) ⁸.

Chlamydia culture

Historically, cell culture to detect Chlamydia trachomatis was the most sensitive and specific method available to detect chlamydial infection. Cell culture, however, is technically complex, expensive, difficult to standardize, and has a lower sensitivity than amplification tests. In addition, performing Chlamydia trachomatis cell culture requires collection of Chlamydia trachomatis elementary bodies from relevant anatomical site(s) and use of stringent transport requirements. Because of their excellent sensitivity and specificity, nucleic acid amplification tests (NAATs) have replaced the use of culture in most clinical situations; the use of culture for Chlamydia trachomatis is primarily limited to evaluation of suspected cases of sexual abuse in children ³¹.

Chlamydia blood test

Serologic testing is rarely used in clinical practice to diagnose genital infections caused by Chlamydia trachomatis and chlamydia serologic tests do not reliably distinguish current from prior infection ³². Two main types of serologic tests are used for diagnosis: (1) chlamydia complement fixation test (CFT), which measures antibody against group-specific lipopolysaccharide antigen, and (2) microimmunofluorescence (MIF) ³³:

1. Chlamydia complement fixation test (CFT), which measures antibody against group specific lipopolysaccharide antigen, and
2. Micro-immunofluorescence (MIF).

Serology may be of value in the diagnosis of anogenital infections (lymphogranuloma venereum) because many clinicians do not have access to OmpA serotyping or genotyping. Complement fixation titers of 1:64 or greater can support the diagnosis of lymphogranuloma venereum in the appropriate clinical context ³⁴. The more sensitive and species-specific micro-immunofluorescence has replaced the chlamydia complement fixation test. High background prevalence and infrequent rises and falls in IgG and IgM make serology less practical to use as a diagnostic test for uncomplicated genital chlamydial infection. Serology may be useful in evaluation of inguinal anogenital infections (lymphogranuloma venereum) and selected chlamydia complications (e.g., perihepatitis and infertility) ³².

Diagnosing lymphogranuloma venereum

Since routinely used NAATs for diagnosing chlamydial infections do not distinguish non-lymphogranuloma venereum (non-LGV) strains of Chlamydia trachomatis from lymphogranuloma venereum (LGV) strains, additional diagnostic methods, such as lymphogranuloma venereum-specific molecular testing with PCR genotyping, are required to make a laboratory diagnosis of lymphogranuloma venereum (LGV). These molecular tests, however, are not widely available and results do not return within a time frame that would alter clinical management ³⁵. In addition, chlamydia serologic testing is not recommended for diagnosing lymphogranuloma venereum (LGV) ¹⁸. Therefore, the diagnosis of lymphogranuloma venereum (LGV) should be based on epidemiologic information, compatible clinical findings, and a positive Chlamydia trachomatis NAAT at the symptomatic anatomic site ¹⁸.

How to read chlamydia test results?

A positive test indicates an active chlamydia 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 to have screening tests performed on an annual basis to check for possible infection, especially since re-infection is common, particularly among teenagers.

If you are infected, your sexual partner(s) should be tested and treated as well.

Chlamydia test limitations

All diagnostic tests including nucleic acid amplification tests (NAATs) can generate inaccurate results, and it is important for patients and clinicians to understand test limitations. Certain false positives and false negatives can occur as a consequence of specimen collection, test operation, and laboratory environment. However, NAATs are far superior in overall performance compared with other Chlamydia trachomatis and Neisseria gonorrhoeae culture and nonculture diagnostic methods. NAATs offer greatly expanded sensitivities of detection, usually well above 90%, while maintaining very high specificity, usually ≥99%. Nucleic acid amplification tests (NAATs) typically detect 20%–50% more chlamydial infections than could be detected by culture or earlier nonculture tests. The increment for detection of gonococcal infections is somewhat less.

Screening for genitourinary chlamydia and gonorrhea infections in Men

Chlamydia (Chlamydia trachomatis) and gonorrhea (Neisseria gonorrhoeae) control efforts in men differ substantially from those recommended for women. Although chlamydia prevalence data have provided a basis for setting age guidelines for routine annual screening and behavioral guidelines for targeted screening in women ³⁶, no such consensus has been reached regarding control program definitions in men who have sex with women ³⁷. Although there are no recommendations to screen heterosexual men, the US Preventive Services Task Force suggests testing to test sexually active heterosexual men in clinical settings with a high prevalence of Chlamydia trachomatis (e.g., STD clinics, adolescent clinics, and detention and correctional facilities) and among persons entering the Armed Forces or the National Job Training Program ³⁸.

The prevalence of gonorrhea varies widely among communities and populations; health-care providers should consider the local gonorrhea epidemiology when making screening recommendations. There is insufficient evidence for or against routine screening for gonorrhea in sexually active heterosexual men at increased risk for infection ³⁸. However, it is not recommended to screen for gonorrhea infections in men at low risk for infection ³⁸.

Overwhelming evidence described the performance of male first catch urine samples as equivalent to, and in some situations superior to, urethral swabs ³⁹. Use of urine samples is highly acceptable and might improve the likelihood of uptake of routine screening in men.

Screening for genitourinary chlamydia and gonorrhea infections in Women

Screening programs have been demonstrated to reduce both the prevalence of Chlamydia trachomatis infection and rates of pelvic inflammatory disease (PID) in women ⁴⁰. Sexually active women aged ≤25 years and women aged >25 years with risk factors (e.g., those who have a new sex partner or multiple partners) should be screened annually for chlamydial infections ³⁸.

The prevalence of gonorrhea varies widely among communities and populations; health-care providers should consider local gonorrhea epidemiology when making screening decisions. Although widespread screening is not recommended, targeted screening of young women (i.e., those aged ≤25 years) at increased risk for infection is a primary component of gonorrhea control in the United States because gonococcal infections among women are frequently asymptomatic. For sexually active women, including those who are pregnant, the U.S. Preventive Services Task Force (USPSTF) recommends that clinicians provide gonorrhea screening only to those at increased risk for infection (e.g., women with previous gonorrhea infection, other STDs, new or multiple sex partners, and inconsistent condom use; those who engage in commercial sex work and drug use; women in certain demographic groups; and those living in communities with a high prevalence of disease). The U.S. Preventive Services Task Force does not recommend screening for gonorrhea in women who are at low risk for infection ³⁸.

For female screening, specimens obtained with a vaginal swab are the preferred specimen type. Vaginal swab specimens are as sensitive as cervical swab specimens, and there is no difference in specificity ⁴¹. Self-collected vaginal swabs are equivalent in sensitivity and specificity to those collected by a clinician ⁴¹. Cervical samples are acceptable when pelvic examinations are done, but vaginal swab specimens are an appropriate sample type, even when a full pelvic exam is being performed. Cervical specimens collected into a liquid cytology medium for Pap screening are acceptable for NAATs that have been cleared by FDA for such specimen types (see Table 1 above). However, following Pap screening, there should be a clinical indication for reflex additional testing of liquid cytology specimens for chlamydia and gonorrhea since these specimen types are more widely used in older populations at low risk for infection. First catch urine from women, while acceptable for screening, might detect up to 10% fewer infections when compared with vaginal and endocervical swab samples ⁴².

Detection of extragenital chlamydia and gonorrhea infections in Men and Women

Infections with chlamydia (Chlamydia trachomatis) and gonorrhea (Neisseria gonorrhoeae) are common in extragenital sites in certain populations such as men who have sex with men. Because extragenital infections are common in men who have sex with men, and most infections are asymptomatic ⁴³, routine annual screening of extragenital sites in men who have sex with men is recommended. No recommendations exist regarding routine extragenital screening in women because studies have focused on genitourinary screening, but rectal and oropharyngeal infections are not uncommon.

A 2003 study that assessed NAATs for diagnosing Chlamydia and gonorrhoeae infections in multiple anatomic sites in men who have sex with men ⁴³ used Becton Dickinson’s ProbeTec NAAT, which had been validated previously for such use. Among 6,434 men who have sex with men attending an STD clinic or a gay men’s clinic, the study found that the prevalence by site for Chlamydia was 7.9% for the rectum, 5.2% urethral, and 1.4% pharyngeal; and prevalence by site for gonorrhoeae was 6.9% for the rectum, 6% urethral, and 9.2% pharyngeal. The great majority (84%) of the gonococcal and chlamydial rectal infections were asymptomatic. More than half (53%) of Chlamydia and 64% of gonorrhoeae infections were at nonurethral sites and would have been missed if the traditional approach to screening of men by testing only urethral specimens had been used.

The scope of the problem of extragenital infection in men who have sex with men is not known at the national level. In 2007, CDC coordinated an evaluation of men who have sex with men attending several community-based organizations and public or STD clinics and found that of approximately 30,000 tests performed, 353 (5.4%) men who have sex with men were positive for rectal infection with gonorrhoeae, and 468 (8.9%) were positive for rectal Chlamydia. Pharyngeal gonorrhoeae tests were positive for 759 men who have sex with men (5.3%), and 54 (1.6%) were positive for Chlamydia ⁴⁴.

In the United Kingdom, some studies on screening men who have sex with men have been performed using NAATs ⁴⁵, and in one study of 3,076 men who have sex with men attending an STD clinic, there was an 8.2% prevalence of infection with Chlamydia in the rectum and 5.4% in the urethra. The majority (69%) of the men with Chlamydia were asymptomatic, stressing the need for screening ⁴⁵.

A study that compared culture to two NAATs (Hologic/Gen-Probe’s Aptima Combo2 [AC2]) and Becton Dickinson’s ProbeTec) for the detection of Chlamydia and gonorrhoeae in pharyngeal and rectal specimens collected from 1,110 men who have sex with men being seen in an STD clinic confirmed all NAAT positive results when either the original test or a test using alternate primers was positive (95). For oropharyngeal gonorrhoeae, sensitivities were 41% for culture, 72% for strand displacement amplification (Becton Dickinson test), and 84% for Hologic/Gen-Probe’s Aptima Combo2 [AC2]; and for rectal gonorrhoeae, sensitivities were 43% for culture, 78% for strand displacement amplification (Becton Dickinson test), and 93% for Hologic/Gen-Probe’s Aptima Combo2 [AC2]. For oropharyngeal infections with Chlamydia (for which only nine infections were detected), sensitivities were 44% for culture, 67% for strand displacement amplification (Becton Dickinson test), and 100% for Hologic/Gen-Probe’s Aptima Combo2 [AC2]; for rectal Chlamydia, sensitivities were 27% for culture, 63% for strand displacement amplification (Becton Dickinson test), and 93% for Hologic/Gen-Probe’s Aptima Combo2 [AC2]. Specificities were >99.4% for all specimens, tests, and anatomic sites. The number of infections detected was more than doubled when a more sensitive NAAT was used as compared with the use of standard culture. Other researchers also have demonstrated the superiority of NAATs as compared with culture for diagnosing Chlamydia and gonorrhoeae in rectal and oropharyngeal sites ⁴⁶.

Although commercially available NAATs are recommended for testing genital tract specimens, they have not been cleared by FDA for the detection of Chlamydia and gonorrhoeae infections of the rectum and oropharynx ⁴⁷. Results from commercially available NAATs can be used for patient management if the laboratory has established specifications for the performance characteristics according to Clinical Laboratory Improvement Amendments (CLIA) regulations ⁴⁸. If a moderate complexity test such as the GeneXpert is modified in any manner, the test defaults to high complexity and the laboratory must meet all high complexity Clinical Laboratory Improvement Amendments (CLIA) requirements, including those for personnel. Certain NAATs that have been demonstrated to detect commensal Neisseria species in urogenital specimens might have comparable low specificity when testing oropharyngeal specimens for gonorrhoeae. Thus, a gonorrhoeae NAAT that does not react with nongonococcal commensal Neisseria species is recommended when testing oropharyngeal specimens (see Table 2 above).

Screening for Chlamydial Infection

Screening for chlamydia in asymptomatic persons has been found to significantly reduce the incidence of chlamydia–associated pelvic inflammatory disease (PID) ⁴⁹.

In general, routine screening for chlamydia should utilize NAAT as the diagnostic test; the United States FDA has cleared NAATs for chlamydia testings on:

1. Male and female urine samples,
2. Clinician-collected endocervical, vaginal, and male urethral samples, and
3. Self-collected vaginal swabs if obtained in a clinical setting.

Routine oropharyngeal screening for Chlamydia trachomatis infection is not recommended, primarily because of the low prevalence of oropharyngeal Chlamydia trachomatis infection. Although chlamydia NAATs for chlamydia are not FDA cleared for rectal samples, the CDC and U.S. Preventive Services Task Force (USPSTF) note that chlamydia NAAT can be used on rectal swabs in persons who engage in receptive anal intercourse. The following summarizes the CDC and USPSTF recommendations for routine chlamydia screening ⁵⁰, ⁵¹.

• Women Who Have Sex with Men: The high frequency of asymptomatic infection among young women combined with greater risk for morbidity led to the recommendation by the CDC and the USPSTF that all sexually active females younger than 25 years of age undergo annual screening for chlamydial infection ⁵⁰. More frequent screenings may be appropriate for sexually active adolescents and women with recent Chlamydia trachomatis infections. In addition, women 25 and older should undergo routine screening if they are considered to have increased risk for chlamydial infection, such as a new sex partner, more than one sex partner, a sex partner with concurrent (overlapping) partners, or a sex partner who has been diagnosed with an sexually transmitted infection (STI or STD). Women diagnosed with chlamydia should have repeat testing approximately 3 months after completing treatment.

• Women Who Have Sex with Women: The CDC recommends that chlamydia screening for sexually active women who have sex with women should be based on the same recommendations as for sexually active women who have sex with men ⁵².

• Pregnancy: At the first prenatal visit, screen all pregnant women younger than 25 and those older than 25 who have increased risk of acquiring chlamydial infection ⁵². Identified factors associated with increased risk for chlamydial infection include a new sex partner, more than one sex partner, a sex partner with concurrent (overlapping) partners, or a sex partner who has been diagnosed with an sexually transmitted disease (STD). Retest for chlamydial infection during the third trimester in women younger than 25 and in women older than 25 who have increased risk of acquiring chlamydial infection. Pregnant women diagnosed with chlamydia should have a test-of-cure 3-4 weeks after completing treatment and they should have repeat testing for chlamydia approximately 3 months after completing treatment.

• Men Who Have Sex Only with Women: Routine screening for chlamydial infection is not recommended by either the CDC or the USPSTF for sexually active men who have sex only with women ⁵⁰. The CDC recommends considering screening for chlamydia in sexually active young men who only have sex with women in populations with a high prevalence of chlamydia, including those seen at adolescent clinics, correctional facilities, and STD clinics ⁵⁰.

• Men Who Have Sex with Men: The CDC recommends routine chlamydia screening in sexually active men who have sex with men at least annually; the screening should consist of testing genital and rectal sites exposed during sexual activity, regardless of a history of condom use during sexual exposure ⁵². Routine testing of oropharyngeal testing for chlamydia infection is not recommended. More frequent screening at 3- to 6-month intervals is indicated for men who have sex, including those with HIV infection, if risk behaviors persist or their sexual partners have multiple partners. The USPSTF does not recommend routine screening for chlamydia in men who have sex with men ⁵³.

• Transgender Men and Women: The CDC recommends that screening for chlamydia in transgender men (“trans-men”) and transgender women (“trans-women”) should be based on age, current anatomy, and sexual practices ⁵².

• Persons with HIV Infection: The CDC recommends performing routine screening for chlamydia for persons with HIV infection who are sexually active; testing for chlamydia should be performed at the initial evaluation and at least annually thereafter (more frequent screening may be indicated based on risk) ⁵⁴. The testing should consist of obtaining samples from the anatomic sites of sexual exposure, with the exception that routine screening for oropharyngeal chlamydia infection is not recommended.

• Correctional Facilities: The CDC recommends performing routine screening for chlamydial infection at the initial intake in a correctional facility for all women 35 and younger and men younger than 30 ⁵².

1. APHL. Laboratory Diagnostic Testing for Chlamydia trachomatis and Neisseria gonorrhoeae. Expert Consultation Meeting Summary Report. January 13-15, 2009. Atlanta, GA.[↩][↩]
2. Schachter J, Chernesky MA, Willis DE, et al. Vaginal swabs are the specimens of choice when screening for Chlamydia trachomatis and Neisseria gonorrhoeae: results from a multicenter evaluation of the APTIMA assays for both infections. Sexually transmitted diseases 2005;32:725-8.[↩]
3. Doshi JS, Power J, Allen E. Acceptability of chlamydia screening using self-taken vaginal swabs. International journal of STD & AIDS 2008;19:507-9.[↩]
4. Bachmann LH, Johnson RE, Cheng H, et al. Nucleic acid amplification tests for diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis rectal infections. Journal of clinical microbiology 2010;48:1827-32.[↩][↩]
5. Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance 2017. Chlamydia. Atlanta: U.S. Department of Health and Human Services; September 2018. https://www.cdc.gov/std/stats17/chlamydia.htm[↩]
6. Cates W, Jr., Wasserheit JN. Genital chlamydial infections: epidemiology and reproductive sequelae. American journal of obstetrics and gynecology 1991;164:1771-81.[↩]
7. Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR, 64(RR-3) (2015). https://www.cdc.gov/std/tg2015/default.htm[↩][↩][↩][↩][↩]
8. Chlamydial Infections. https://www.cdc.gov/std/treatment-guidelines/chlamydia.htm[↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩]
9. Wiesenfeld HC. Screening for Chlamydia trachomatis Infections in Women. N Engl J Med. 2017 Feb 23;376(8):765-773. doi: 10.1056/NEJMcp1412935[↩]
10. Jeanne M. Marrazzo, David H. Martin, Management of Women with Cervicitis, Clinical Infectious Diseases, Volume 44, Issue Supplement_3, April 2007, Pages S102–S110, https://doi.org/10.1086/511423[↩]
11. Brunham RC, Gottlieb SL, Paavonen J. Pelvic inflammatory disease. N Engl J Med. 2015 May 21;372(21):2039-48. doi: 10.1056/NEJMra1411426[↩]
12. Ness RB, Soper DE, Holley RL, Peipert J, Randall H, Sweet RL, Sondheimer SJ, Hendrix SL, Amortegui A, Trucco G, Songer T, Lave JR, Hillier SL, Bass DC, Kelsey SF. Effectiveness of inpatient and outpatient treatment strategies for women with pelvic inflammatory disease: results from the Pelvic Inflammatory Disease Evaluation and Clinical Health (PEACH) Randomized Trial. Am J Obstet Gynecol. 2002 May;186(5):929-37. doi: 10.1067/mob.2002.121625[↩]
13. Brunham RC, Binns B, McDowell J, Paraskevas M. Chlamydia trachomatis infection in women with ectopic pregnancy. Obstet Gynecol. 1986 May;67(5):722-6. doi: 10.1097/00006250-198605000-00022[↩]
14. Chlamydia – CDC Basic Fact Sheet. https://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm[↩]
15. Chlamydial Infections. Sexually Transmitted Infections Treatment Guidelines, 2021. https://www.cdc.gov/std/treatment-guidelines/chlamydia.htm[↩]
16. Marcus JL, Kohn RP, Barry PM, Philip SS, Bernstein KT. Chlamydia trachomatis and Neisseria gonorrhoeae transmission from the female oropharynx to the male urethra. Sex Transm Dis. 2011 May;38(5):372-3. doi: 10.1097/OLQ.0b013e3182029008[↩]
17. Kyle T. Bernstein, Sally C. Stephens, Pennan M. Barry, Robert Kohn, Susan S. Philip, Sally Liska, Jeffrey D. Klausner, Chlamydia trachomatis and Neisseria gonorrhoeae Transmission from the Oropharynx to the Urethra among Men who have Sex with Men, Clinical Infectious Diseases, Volume 49, Issue 12, 15 December 2009, Pages 1793–1797, https://doi.org/10.1086/648427[↩]
18. Lymphogranuloma Venereum (LGV). https://www.cdc.gov/std/treatment-guidelines/lgv.htm[↩][↩][↩][↩][↩]
19. Golden MR, Whittington WL, Handsfield HH, Hughes JP, Stamm WE, Hogben M, Clark A, Malinski C, Helmers JR, Thomas KK, Holmes KK. Effect of expedited treatment of sex partners on recurrent or persistent gonorrhea or chlamydial infection. N Engl J Med. 2005 Feb 17;352(7):676-85. doi: 10.1056/NEJMoa041681[↩]
20. Schillinger JA, Kissinger P, Calvet H, Whittington WL, Ransom RL, Sternberg MR, Berman SM, Kent CK, Martin DH, Oh MK, Handsfield HH, Bolan G, Markowitz LE, Fortenberry JD. Patient-delivered partner treatment with azithromycin to prevent repeated Chlamydia trachomatis infection among women: a randomized, controlled trial. Sex Transm Dis. 2003 Jan;30(1):49-56. doi: 10.1097/00007435-200301000-00011[↩]
21. Klausner JD, Chaw JK. Patient-delivered therapy for chlamydia: putting research into practice. Sex Transm Dis. 2003 Jun;30(6):509-11. doi: 10.1097/00007435-200306000-00007[↩]
22. Eberly MD, Eide MB, Thompson JL, Nylund CM. Azithromycin in early infancy and pyloric stenosis. Pediatrics. 2015 Mar;135(3):483-8. doi: 10.1542/peds.2014-2026[↩][↩]
23. Smith C, Egunsola O, Choonara I, Kotecha S, Jacqz-Aigrain E, Sammons H. Use and safety of azithromycin in neonates: a systematic review. BMJ Open. 2015 Dec 9;5(12):e008194. doi: 10.1136/bmjopen-2015-008194[↩]
24. FDA clears first diagnostic tests for extragenital testing for chlamydia and gonorrhea. https://www.fda.gov/news-events/press-announcements/fda-clears-first-diagnostic-tests-extragenital-testing-chlamydia-and-gonorrhea[↩]
25. Lunny C, Taylor D, Hoang L, Wong T, Gilbert M, Lester R, Krajden M, Ogilvie G. Self-Collected versus Clinician-Collected Sampling for Chlamydia and Gonorrhea Screening: A Systemic Review and Meta-Analysis. PLoS One. 2015 Jul 13;10(7):e0132776. doi: 10.1371/journal.pone.0132776[↩]
26. Masek BJ, Arora N, Quinn N, Aumakhan B, Holden J, Hardick A, Agreda P, Barnes M, Gaydos CA. Performance of three nucleic acid amplification tests for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by use of self-collected vaginal swabs obtained via an Internet-based screening program. J Clin Microbiol. 2009 Jun;47(6):1663-7. doi: 10.1128/JCM.02387-08[↩]
27. van der Helm JJ, Hoebe CJ, van Rooijen MS, Brouwers EE, Fennema HS, Thiesbrummel HF, Dukers-Muijrers NH. High performance and acceptability of self-collected rectal swabs for diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae in men who have sex with men and women. Sex Transm Dis. 2009 Aug;36(8):493-7. doi: 10.1097/OLQ.0b013e3181a44b8c[↩]
28. FDA Allows for First Point-of-Care Chlamydia and Gonorrhea Test to be Used in More Near-Patient Care Settings. https://www.fda.gov/news-events/press-announcements/fda-allows-first-point-care-chlamydia-and-gonorrhea-test-be-used-more-near-patient-care-settings[↩][↩][↩]
29. Van Der Pol B, Taylor SN, Mena L, Lebed J, McNeil CJ, Crane L, Ermel A, Sukhija-Cohen A, Gaydos CA. Evaluation of the Performance of a Point-of-Care Test for Chlamydia and Gonorrhea. JAMA Netw Open. 2020 May 1;3(5):e204819. doi: 10.1001/jamanetworkopen.2020.4819[↩][↩][↩]
30. Jensen IP, Fogh H, Prag J. Diagnosis of Chlamydia trachomatis infections in a sexually transmitted disease clinic: evaluation of a urine sample tested by enzyme immunoassay and polymerase chain reaction in comparison with a cervical and/or a urethral swab tested by culture and polymerase chain reaction. Clin Microbiol Infect. 2003 Mar;9(3):194-201. doi: 10.1046/j.1469-0691.2003.00483.x[↩]
31. Chlamydial Infections. https://www.std.uw.edu/go/comprehensive-study/chlamydial-infections/core-concept/all[↩]
32. Chlamydia https://www.std.uw.edu/go/pathogen-based/chlamydia/core-concept/all[↩][↩]
33. Centers for Disease Control and Prevention. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae–2014. MMWR Recomm Rep. 2014 Mar 14;63(RR-02):1-19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4047970[↩]
34. Mabey D, Peeling RW. Lymphogranuloma venereum. Sex Transm Infect. 2002;78:90-2.[↩]
35. Centers for Disease Control and Prevention. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae–2014. MMWR Recomm Rep. 2014 Mar 14;63(RR-02):1-19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4047970/[↩]
36. US Preventive Services Task Force. Screening for chlamydial infection: recommendation statement. Ann Intern Med 2007;147:128–34.[↩]
37. CDC. Male chlamydia screening consultation, Atlanta, Georgia, March 28–29, 2006. Meeting Report, May 22, 2007. Atlanta, GA: US Department of Health and Human Services, CDC; 2007. https://www.cdc.gov/std/chlamydia/ChlamydiaScreening-males.pdf[↩]
38. US Preventive Services Task Force. Screening for gonorrhea: recommendation statement. Ann Fam Med 2005;3:263–7.[↩][↩][↩][↩][↩]
39. Gaydos CA, Ferrero DV, Papp JR. Laboratory aspects of screening men for Chlamydia trachomatis in the new millennium. Sex Transm Dis 2008;35(Suppl):S44–50.[↩]
40. Scholes D, Stergachis A, Heidrich FE, et al. Prevention of pelvic inflammatory disease by screening for cervical chlamydial infection. N Engl J Med 1996;334:1362–6.[↩]
41. Masek BJ, Arora N, Quinn N, et al. Performance of three nucleic acid amplification tests for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by use of self-collected vaginal swabs obtained via an Internet-based screening program. J Clin Microbiol 2009;47:1663–7.[↩][↩]
42. Falk L, Coble BI, Mjörnberg PA, Fredlund H. Sampling for Chlamydia trachomatis infection–a comparison of vaginal, first-catch urine, combined vaginal and first-catch urine and endocervical sampling. Int J STD AIDS 2010;21:283–7.[↩]
43. Kent CK, Chaw JK, Wong W, et al. Prevalence of rectal, urethral, and pharyngeal chlamydia and gonorrhea detected in 2 clinical settings among men who have sex with men: San Francisco, California, 2003. Clin Infect Dis 2005;41:67–74.[↩][↩]
44. CDC. Clinic-based testing for rectal and pharyngeal Neisseria gonorrhoeae and Chlamydia trachomatis infections by community-based organizations—five cities, United States, 2007. MMWR 2009;58:716–9. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5826a2.htm[↩]
45. Annan NT, Sullivan AK, Nori A, et al. Rectal chlamydia–a reservoir of undiagnosed infection in men who have sex with men. Sex Transm Infect 2009;85:176–9.[↩][↩]
46. Bachmann LH, Johnson RE, Cheng H, et al. Nucleic acid amplification tests for diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis rectal infections. J Clin Microbiol 2010;48:1827–32.[↩]
47. Recommendations for the Laboratory-Based Detection of Chlamydia trachomatis and Neisseria gonorrhoeae — 2014. https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6302a1.htm[↩]
48. Girardet RG, Lahoti S, Howard LA, et al. Epidemiology of sexually transmitted infections in suspected child victims of sexual assault. Pediatrics 2009;124:79–86.[↩]
49. Hu D, Hook EW 3rd, Goldie SJ. Screening for Chlamydia trachomatis in women 15 to 29 years of age: a cost-effectiveness analysis. Ann Intern Med. 2004;141:501-13.[↩]
50. Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. Chlamydial infections. MMWR Recomm Rep. 2015;64(No. RR-3):1-137. https://www.cdc.gov/std/tg2015/chlamydia.htm[↩][↩][↩][↩]
51. Meyers D, Wolff T, Gregory K, et al. USPSTF recommendations for STI screening. Am Fam Physician. 2008;77:819-24.[↩]
52. Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. Special populations. MMWR Recomm Rep. 2015;64(No. RR-3):1-137. https://www.cdc.gov/std/tg2015/specialpops.htm[↩][↩][↩][↩][↩]
53. LeFevre ML; U.S. Preventive Services Task Force. Screening for Chlamydia and gonorrhea: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;161:902-10.[↩]
54. Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. HIV infection: detection, counseling, and referral. MMWR Recomm Rep. 2015;64(No. RR-3):1-137. https://www.cdc.gov/std/tg2015/hiv.htm[↩]