Background
Chlamydiae are obligate intracellular organisms from bacteria that now comprise 3 species. They include the following: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae.
C trachomatis, which is almost exclusively a human pathogen, includes the agents of classic trachoma (ie, serotypes A, B, Ba, C). It also includes the agents of inclusion conjunctivitis or paratrachoma (ie, serotypes D-K). The latter organisms infect the epithelium of mucoid surfaces and were once identified as the trachoma-inclusion conjunctivitis agents (TRIC). Serotypes L1, L2, and L3, the agents that infect tissues deeper to the epithelium and cause lymphogranuloma venereum, also are included.
C trachomatis is the most common cause of chronic follicular conjunctivitis (ie, follicular conjunctivitis lasting for >16-28 d). The organism also causes 3 clinical syndromes, which include the following: trachoma, adult inclusion conjunctivitis, and neonatal conjunctivitis. Trachoma and neonatal conjunctivitis are discussed in other chapters so this discussion is restricted to adult inclusion conjunctivitis.
Adult inclusion conjunctivitis results from C trachomatis serotypes D-K, causing chronic follicular conjunctivitis that can occur in adults or in the neonate. The adult disease is transmitted sexually or from hand-to-eye contact. Gonorrhea is the most common co-infection with adult inclusion conjunctivitis. Rarely, the adult disease is transmitted from eye-to-eye contact (eg, sharing mascara).
This image reveals a close view of a patient’s left eye with the upper lid retracted in order to reveal the inflamed conjunctival membrane lining the inside of both the upper and lower lids, due to what was determined to be a case of inclusion conjunctivitis, a type of conjunctival inflammation caused by the bacterium, Chlamydia trachomatis. Inclusion conjunctivitis, also known as chlamydial conjunctivitis, is more common in newborns. Symptoms include redness of the eye(s), swelling of the eyelids, and discharge of pus, usually 5 to 12 days after birth. Image courtesy of Susan Lindsley, Centers for Disease Control and Prevention.
Also see the Medscape Reference article Chlamydial Genitourinary Infections.