Methods of specimen collection for the diagnosis of STIs.

Many of the landmark discoveries with regard to the etiology, 2. Gram staining for gonorrhea, non-gonococcal urethritis, pathogenesis and epidemiology of sexually transmitted chancroid, bacterial vaginosis infections (STIs) occurred with the use of various diagnostic 3. Tzanck smear for herpes genitalis, donovanosis, techniques many years ago.[1] However, the concept of molluscum contagiosum providing comprehensive laboratory services for the 4. Wet mount for trichomoniasis diagnosis of STIs has surfaced relatively recently. The correct 5. KOH wet mount for candidiasis method of specimen collection helps in achieving desirable 6. Bubo aspiration and smear for LGV and chancroid goals in the laboratory diagnosis of STIs. If simple precautions are taken, it will avoid spurious results. The collection of DARK-FIELD MICROSCOPY specimens and use of the appropriate swab and transport media are vital in the success of tissue culture. Dark-field examination is most productive in primary, secondary and early congenital syphilis, when moist lesions Principles to be followed while collecting containing large numbers of treponemes (e.g., chancres, specimens:[1] condylomata lata, umbilical cord or mucous patches) are Communication with laboratory staff to discuss collection, present.[2-4] Aspirate from enlarged regional lymph nodes transport and testing of specimens. and cervical and vaginal specimens can also be used, but oral All procedures should be performed while wearing lesions are avoided as even an experienced observer may appropriate protective gear. find it difficult to differentiate T. pallidum from saprophytic Avoid contamination by indigenous commensal flora. spirochetes. The specimen for dark-field microscopy consists Adequate volumes of each specimen should be of serous fluid that contains T. pallidum, but should be free of collected. erythrocytes, other organisms and tissue debris. 1.