NON-SPECIFIC URETHRITIS

Non-specific urethritis (also called non-gonococcal urethritis) are referred to those cases of urethritis which are culture negative for gonococci.

Etiology:  
The most common cause of NSU in men is Chlamydia trachomatis (D-K). C.trachomatis is isolated in most men with NSU and upto 80% of men with post-gonococcal urethritis. Other etiological agents include Ureaplasma urealyticum and Mycoplasma genitilium.

Clinical features:  
NGU is more commonly seen in males than females. Men with NGU have less dysuria and a less purulent discharge than those with gonococcal urethritis. In women, the urethritis is most often asymptomatic.

Complications:  
In men Chlamydial infections could lead to "idiopathic epidydimitis" and in women to salpingitis, endometritis and PID.

Laboratory diagnosis:  
Specimen collection: When chlamydia is suspected, the urethral discharge is not useful, instead urethral scraping is a suitable specimen. A urethral swab may be used in females after the mucus is cleaned away. Scraping from the endocervix is preferred in females. Urethral discharge may be collected to demonstrate Ureaplasma.

Direct microscopy: Demonstration of elementary bodies (of C.trachomatis) by
a) Giemsa's stain, Iodine stain, Machhiavello stain etc
b) Immunofluorescence and immunoperoxidase

Culture: On cycloheximide treated McCoy cells (for C.trachomatis). Ureaplasma is cultured on a special medium containing 10% urea.

Enzyme immunoassay: Chlamydial antigens from the urethral scraping may be detected by sensitive enzyme immunoassay techniques.

Molecular methods: Polymerase chain reaction (PCR) and Ligase chain reaction (LCR) are very useful and reliable in detecting Chlamydial nucleic acids in the urethral scraping.