infectious diseases
Chlamydia
Diagnosis ofChlamydia
ForC. trachomatis, nucleic acid–based testing ForC. pneumoniae, culture or nucleic acid–based testing ForC. psittaci, serologic tests or polymerase chain reaction (PCR; where available) (See also the CDC's2021 Sexually Transmitted Infections Treatment Guidelines: Chlamydial Infections.) C. trachomatisSTIs are best identified in genital samples using nucleic acid amplification tests (NAATs) because these tests are more sensitive than cell culture and have less stringent sample handling requirements. Currently, NAATs are available for testing genital and urine specimens from adults and adolescents. NAATs for genital infection can be done using urine or vaginal swabs obtained by the patient or clinician. Several commercially available NAATs have been approved for extragenital infections (eg, those in the rectum or pharynx). Serologic tests are of limited value except for diagnosing lymphogranuloma venereum and psittacosis. C. pneumoniaeis diagnosed by culture of respiratory tract specimens or by NAAT testing. Two NAATs forC. pneumoniaeare available as part of panels that simultaneously test for multiple respiratory pathogens. A primary clue to the diagnosis ofC. psittaciinfection is close contact with birds, typically pet birds such as parrots or parakeets, including veterinarians and workers in turkey and duck processing plants. Diagnosis is confirmed by serologic tests. Culture is not generally available. There are no commercially available NAATs forC. psittaci, but PCR can be done by the Centers for Disease Control and Prevention (CDC) and some specialty laboratories. (See also the CDC'sdifferent methods for diagnosing psittacosis.) 1.Kohlhoff S, Roblin PM, Clement S, et al: Universal prenatal screening and testing andChlamydia trachomatisconjunctivitis in infants.Sex Transm Dis48(9):e122–e123, 2021. doi: 10.1097/OLQ.0000000000001344 