Sexually transmitted chlamydia : The symptoms of common chlamydial STD and gonorrhea are very similar, so accurate diagnosis can be important. Although, in practice it is standard to treat for both and not bother with the expensive testing often necessary to prove the diagnosis.

A swab test from the discharge of the penis or the cervix is the most reliable method for detecting chlamydia. A urine sample may be used as well. You may also be tested for others STDs, including HIV .

Diagnosing other forms of chlamydial infection depend upon a combination of your medical history (such as exposures to birds, sexual partners, foreign travel), your physical examination, and a collection of laboratory tests. In some cases, making the diagnosis can be quite difficult.

  • Psittacosis : The diagnosis of psittacosis is difficult when an obvious history of exposure to birds is not present. There is a laboratory test called complement fixation that identifies antibodies to the germ and is performed by the Center for Disease Control and Prevention.
  • Trachoma : Trachoma is diagnosed 1) by culturing a swab from the conjunctiva, 2) by examining cells scraped from the conjunctiva, and in later stages 3) by magnified examination of the eye.
  • Reiter’s syndrome : The diagnosis of Reiter’s syndrome depends entirely upon your symptoms and, since all three symptoms may take some time to appear, may be delayed for several months.

Definitive diagnosis utilizes a number of different techniques including culturing specimens from infected areas, identifying molecules associated with the germ or antibodies to the germ that you have formed, and recognizing strands of nucleic acid unique to the germ. The latter is done by using the newest methods of molecular biology, such as polymerase chain reactions and nucleic acid probes.