Virology / Serology: Chlamydia / Gonorrhea Frequently Asked Questions
- What patient populations are tested with the APTIMA Combo 2 test for CT/GC?
All prenatal patients, symptomatic females, and asymptomatic females under 26 years of age are tested for both Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). Additional testing criteria was added in 2007 to include vaginal swab samples from women to retest for Chlamydia/Gonorrhea at three months post-treatment, from women due to sex partner referral, from women with high risk history (i.e. new partner, multiple partners, etc.), and for Chlamydia testing prior to IUD insertion.
- What is the proper order for specimen collection?
Collect the specimen for CT/GC NAAT testing in the order sequence recommended by your current clinical protocols.
- What about urine testing?
Urine testing for C. trachomatis and N. gonorrhoeae is available on a limited basis to pre-approved, select sites.
- What about testing of male patients?
Specimens from male patients are not being accepted at this time. The State Laboratory accepts vaginal swab specimens only from females who fit the testing criteria previously stated.
- What about females with hysterectomies?
Females with hysterectomies that present with clinical symptoms of CT infections can be tested using the vaginal swab collection kit for sample collection.
- How do we order more CT/GC NAAT collection kits?
Collection kits can be ordered by clicking on Order Supplies Online on the main website page. The vaginal swab kits are packaged and sold in boxes of 50. A minimal order is 1 box of swabs (50 swabs).
- How do we get more DHHS Form #4011 forms?
Download the PDF - DHHS Chlamydia/Gonorrhea Detection Form #4011 (PDF, 79 KB). All State Laboratory forms can be accessed from this website, downloaded, and printed on site from the forms page. Please use white paper only.
- What happens if we submit a specimen with an incorrectly broken vaginal swab?
If a specimen is submitted with an incorrectly broken swab or no swab, it will be rejected. Please refer to Specimen Collection for the proper collection procedure for collecting vaginal swab specimens. These procedures can also be found (1) inside the lid of the box containing the collection swabs, (2) on the packaging of the swab itself, and (3) by viewing the Chlamydia/Gonorrhea Vaginal Specimen Collection and Form Training PowerPoint Presentation . Care must be taken to break the vaginal swab off correctly at the marked scoreline after placing the swab into the vaginal swab collection tube. Swabs which are too long or too short cannot be tested and will be rejected by the laboratory.
- How should labels be placed on the transport tube?
Place labels on the transport tubes horizontally (lengthwise). Label should be smooth with no wrinkles and not extend past the bottom of the tube or cover the cap. Do not apply the label in a spiral or flag-like orientation. Alternatively, the patient information may be hand-written on the existing manufacturer’s label.
- Why must the CT/GC Test Information Section of DHHS Form #4011 be completed?
The information is used to determine whether or not the specimen meets our criteria for testing. It is imperative that this section of DHHS Chlamydia/Gonorrhea Detection Form #4011 (PDF, 79 KB) be completely filled in. Failure to provide this information may result in delayed testing or rejection of the specimen. The "Signs/Symptoms" and "Pregnancy Status" boxes must be checked even though patients were seen in Prenatal or STD Clinics.
- What if only CT is requested? What if only GC is requested?
The APTIMA Combo 2 Test amplifies and detects both organisms simultaneously. Therefore all specimens are tested for CT and GC and results for both tests are reported. The DHHS Chlamydia/Gonorrhea Detection Form #4011 (PDF, 79 KB) allows for only one option in ordering and that is the combination testing of CT and GC.
- What are the instructions for shipping specimens using the double mailers?
Please see Packing Instructions Using Outer Baggie (PDF, 4.6 MB) for an illustrated tutorial on packaging specimens for shipment. Remember to limit each mailer to 6 CT/GC specimens and stamp the return address on the outside of each mailer.
- What are the sensitivity, specificity and predictive values of the APTIMA Combo 2 assay?
In both the literature review of the assay and the method verification conducted by the State Laboratory, the sensitivity and specificity of the assay in the detection of both CT and GC approaches 100%. However, no test should ever be considered 100% sensitive or 100% specific. Laboratory tests aid the clinician in establishing a diagnosis but should never be the sole criteria used to establish a diagnosis.
- Does blood interfere with assay performance?
Due to the advances in technology that are a part of the APTIMA technology, blood will not interfere with the performance of the assay.
- Can we get test results from this website by "reported date" as well as by "individual name" or "SSN"?
Yes. Here are the steps to get the results:
- Click on "Lab Test Results Lookup" on the main page.
- Enter log in information and click "Login" link if you have created yourself an account. If you do not have an account, click the "Create New Account" link to create yourself an account.
- Click the "Lab Tests" option to get to the lab test search screen.
- Click the "Choose Search Type" option to view list of searchable options.
- Click the "Reported Date" option from the search type list.
- Click the lab test (Chlamydia), enter your EIN, and enter the reported date to search.
- If there are test results that match your search criteria, they will be listed for you.
- Click on Lab Number (Filing Number) for the test result to view/print result.
- What are the guidelines for follow-up testing with the APTIMA assay for Chlamydia and Gonorrhea?
Follow-up testing for Chlamydia
The 2015 CDC STD Treatment Guidelines state: "Test-of-cure to detect therapeutic failure (i.e., repeat testing 3-4 weeks after completing therapy) is not advised for persons treated with the recommended or alternative regimens, unless therapeutic adherence is in question, symptoms persist, or reinfection is suspected. Moreover, the use of chlamydial NAATs at <3 weeks after completion of therapy is not recommended because the continued presence of nonviable organisms can lead to false-positive results. A high prevalence of C. trachomatis infection has been observed in women and men who were treated for chlamydial infection during the preceding several months. Most post-treatment infections do not result from treatment failure, but rather from reinfection caused by failure of sex partners to receive treatment or the initiation of sexual activity with a new infected partner, indicating a need for improved education and treatment of sex partners. Repeat infections confer an elevated risk for PID and other complications in women. Men and women who have been treated for chlamydia should be retested approximately 3 months after treatment, regardless of whether they believe that their sex partners were treated. If retesting at 3 months is not possible, clinicians should retest whenever persons next present for medical care in the 12-month period following initial treatment."
Follow-up testing for Gonorrhea
The 2015 CDC STD Treatment Guidelines state: "A test-of-cure is not needed for persons who receive a diagnosis of uncomplicated urogenital or rectal gonorrhea who are not treated with any of the recommended or alternative regimens; however, any person with pharyngeal gonorrhea who is treated with an alternative regimen should return 14 days after treatment for a test-of-cure using either culture or NAAT. If the NAAT is positive, effort should be made to perform a confirmatory culture before retreatment. All positive cultures for test-of-cure should undergo antimicrobial susceptibility testing. Symptoms that persist after treatment should be evaluated by culture for N. gonorrhoeae (with or without simultaneous NAAT), and any gonococci isolated should be tested for antimicrobial susceptibility. Persistent urethritis, cervicitis, or proctitis also might be caused by other organisms. A high prevalence on N. gonorrhoeae infection has been among men and women previously treated for gonorrhea. Rather than signaling treatment failure, most of these infections result from reinfection caused by failure of sex partners to receive treatment or the initiation of sexual activity with a new infected partner, indicating a need for improved patient education and treatment of sex partners. Men or women who have been treated for gonorrhea should be retested 3 months after treatment regardless of whether they believe that sex partners were treated. If testing at 3 months is not possible, clinicians should retest whenever persons next present for medical care within 12 months following initial treatment."
- Are chlamydia cultures still done at the State Laboratory?
Chlamydia cell cultures are no longer performed at the State Laboratory. This procedure, if needed, is available from commercial reference laboratories.
- Who do we contact if we have more questions or need further clarification?
Please feel free to contact Myra Brinson or Mark Turner at (919) 733-7544 if you have further questions or are in need of assistance.