Virology / Serology - Chlamydia
Chlamydia are obligate intracellular bacteria known to infect a variety of animal and bird species as well as humans. The genus Chlamydia consists of three recognized species:
Chlamydia Pneumoniae
Chlamydia pneumoniae is transmitted man-to-man and is responsible for acute respiratory disease, pneumonia, and pharyngitis. The principal diagnosis of infection with this agent is serological assessment via the micro-immunofluorescent antibody (MIFA) assay, performed at the CDC. Please see CDC Referral for information to arrange serologic testing for this agent.
Chlamydia Psittaci
Chlamydia psittaci (ornithosis or parrot fever) is a zoonotic agent transmitted from psittacine birds to man. It may cause pneumonia which is clinically indistinguishable from that caused by C. pneumoniae, mycoplasma, or Q fever. Cultivation of this agent in cell culture is difficult and very hazardous, hence; this laboratory does not attempt to culture for psittacosis. Laboratory diagnosis is by serological assessment via the MIFA assay, performed at the CDC. Please see CDC Referral for information to arrange serologic testing for this agent.
Chlamydia Trachomatis
Chlamydia trachomatis consists of a group of 15 different serovars. Collectively, these different variants cause a clinical spectrum including conjunctivitis, pneumonia, lymphogranuloma venereum (LGV), and assorted urogenital infections. Serovars D through K are the major cause of genital chlamydial infections in men and women. These infections are the most common sexually transmitted diseases worldwide. Since C. trachomatis infections are often asymptomatic in both males and females, undetected cases may lead to pelvic inflammatory disease (PID) and subsequent infertility in women. Children born to infected mothers are at significantly higher risk for inclusion conjunctivitis and chlamydial pneumonia.
The diagnostic testing for C. trachomatis at the State Laboratory is a nucleic acid amplification test that dually detects Chlamydia trachomatis and Neisseria gonorrhea on a single endocervical swab specimen. Cell culture for C. trachomatis is no longer available at the State Laboratory. Please call the Virology/Serology Unit Supervisor at 919-733-7544 for guidance related to the collection and submission of specimens to CDC for cases of suspected LGV.
Specimen Acceptance Policy
Chlamydia trachomatis/Neisseria gonorrhoeae laboratory services are subject to the following guidelines which have been developed to ensure proper patient management and efficient utilization of limited resources. Only the following specimens will be accepted from local health departments:
- Endocervical swab specimens from women with syndromes compatible with C.trachomatis and/or N. gonorrhea infection
- Endocervical swab specimens from pregnant females
- Endocervical swab specimens from asymptomatic women, 24 years old and younger, seen in either Family Planning or Sexually Transmitted Disease clinics
Submitted specimens must be accompanied by a fully completed submission form (DHHS #4011). Failure to supply the requested patient information may result in significantly delayed specimen testing or in specimens being rejected. Specimens for diagnostic testing not labeled with correct patient identification information will not be tested. Minimal patient specimen identification includes full first and last name and either SSN or date of birth. Specimens which, for any reason, are deemed unsuitable or inappropriate for diagnostic testing will not be tested. Rejected specimens will be properly stored for thirty days pending verbal and/or written notification of the submitter. Unless alternate arrangements are initiated by the submitter upon notification of specimen rejection, the specimen will be discarded at the end of the holding period.
Specimen Collection
Specimens from the endocervix are obtained by the following procedure:
- Remove excess mucus from cervical os and surrounding mucosa using cleaning swab (white shaft swab in package with red printing). Discard this swab.
- Insert specimen collection swab (blue shaft swab in package with green printing) into endocervical canal.
- Gently rotate swab clockwise for 10 to 30 seconds in endocervical canal to ensure adequate sampling.
- Withdraw swab carefully; avoid any contact with vaginal mucosa.
- Remove cap from swab specimen transport tube and immediately place specimen collection swab into specimen transport tube.
- Carefully break swab shaft at scoreline; use care to avoid splashing contents.
- Re-cap swab specimen transport tube tightly.
Clearly label specimen transport tube with the patient´s full first and last name and either SSN or date of birth. Complete (DHHS #4011). (downloaded and printed from this website) with the required information.
Specimen Shipping
Properly identified specimen transport tubes and completed submission forms should be sent in goldenrod colored specimen mailers labeled CHLAMYDIA/GONORRHEA DETECTION. For detailed shipping instructions using the double mailers, see Packing Instructions Using Outer Baggie. Ship at ambient temperature by the State Courier or U.S. Mail. Specimens are stable for 60 days at room temperature after collection; however, it is advisable to ship as soon as possible to avoid delays in turn-around time of test results.
Specimen collection swab kits and goldenrod colored specimen mailers are available through the NCSLPH online supply ordering system at this website. Store collection materials at room temperature.
Results Reporting
Clinical specimens that test positive for chlamydia and gonorrhea will be reported as "C. trachomatis RNA detected" and "N. gonorrhea RNA detected", respectively. All positive results will include the comment "Therapeutic failure or success cannot be determined with this assay since nucleic acid may persist for several weeks following appropriate antimicrobial therapy." Negative laboratory results for chlamydia and gonorrhea will be reported as "C. trachomatis RNA not detected" and "N. gonorrhea RNA not detected", respectively. An equivocal result for either test will be reported as indeterminate, in which case, another specimen should be properly collected and submitted to resolve the status of the patient. Results should be interpreted in conjunction with patient history and clinical findings.
Chlamydia and gonorrhea test results are available within two working days after receipt of the specimen. These results can be accessed on the main page by clicking on Lab Test Results Lookup.
Data indicates the sensitivity and specificity of the APTIMA assay is nearly 100%. However, it must be remembered that the results of this test are not 100% predictive of every patient’s true infected status.
Relevant Links:
See also:
- About Virology / Serology
- Chlamydia
- HIV
- Hepatitis
- Syphilis
- Special Serology
- CDC Referral
- Arbovirus
- Norovirus
