**4. History**

Trachoma has been described in BC China and Egypt. The role of chlamydia in genital infections was understood at the beginning of the twentieth century. Inclusion bodies were first demonstrated in 1909 in the conjunctival cells of infants with nongonococcal ophthalmia neonatorum, in the cervical epithelial cells of their mothers, and in the urethral epithelial cells of male patients. In the samples, they showed intracytoplasmic inclusion bodies with the Giemsa method. Thinking they were protozoa, they named them Chlamydiazoae. In Greek, "chlamys" means a curtain that covers the environment and describes the inclusions that surround the cell nucleus [12]. Lymphogranuloma venereum was first described by scientists in 1913. An epidemic

*The Laboratory Diagnosis of* Chlamydia *Infections DOI: http://dx.doi.org/10.5772/intechopen.110464*

was studied in Switzerland in 1879 and was named pneumotyphus. Later, in a study on parrots in 1892, the term psittacosis was used. The term psittacosis comes from the Greek "parrot." The psittacosis agent, *C. psittaci*, was first produced in fertilized chicken eggs in 1935 and in cell culture in 1941 [4, 12].

*Chlamydia pneumoniae* was first isolated from a conjunctival swab of a child participating in the trachoma vaccine trial in Taiwan. It was named TW-183. The agent AR-39, isolated from the throat swab of a student with pharyngitis at Seattle University in 1983, was named. The name TWAR (TW + AR) was formed from the first conjunctival strain and the respiratory strain. *C. pneumoniae* strain was defined by morphological examinations and DNA sequence analysis performed in 1989 [4, 12].
