The second most common infectious etiology of vaginal discharge is vulvovaginal candidiasis (VVC ) , more commonly referred to as a yeast infection . VVC is caused by overgrowth of the fungal organism Candida albicans or less commonly Candida glabrata or Candida parapsilosis, which are all part of the normal vaginal flora. Like BV, VVC is not considered to be sexually transmitted. Risk factors for developing VVC include frequent intercourse, use of oral contraceptives, IUD use, antibiotic use, uncontrolled diabetes, immunosuppression, and pregnancy [4]. Most females are diagnosed with a yeast infection at least once during their reproductive years and frequently have recurrences. VVC presents with thick, cottage cheese-like, white, odorless vaginal discharge which tends to be pruritic. VVC is diagnosed by the presence of hyphae, pseudohyphae, or budding yeast on wet mount (Fig. 13.2), by a positive fungal culture. The Affirm VPIII Microbial Identification Test (Becton Dickinson, Sparks, MD) is a DNA probe test that can detect Candida species, as well as BV and T. vaginalis. VVC can be treated with intravaginal application of over-the-counter azole antifungal creams (such as clotrimazole 1% cream, 5 g intravaginally for 7 days or miconazole 2% cream, 5 g intravaginally for 7 days), prescription antifungal creams (like terconazole 80 mg vaginal suppository daily for 3 days), or a single oral dose of fluconazole 150 mg [3]. For a complete list of all Centers for Disease Control and Prevention (CDC)-recommended VVC treatment regimens, see www.​cdc.​gov/​std/​tg2015/​candidiasis.​htm.

The third most common infectious cause of vaginal discharge is trichomoniasis , caused by the sexually transmitted parasite, T. vaginalis . Clinical hallmarks of this infection include frothy gray or green vaginal discharge, vaginal itching, and a “strawberry cervix” caused by cervical petechiae (Fig. 13.3). Trichomonas infection can be diagnosed with trichomonas NAAT testing which is extremely sensitive (clinical sensitivity of 95–100%) and can detect the parasitic infection three to five times more often compared to wet mount microscopy [5]. The CLIA-waived OSOM Trichomonas Rapid Test (Sekishi Diagnostics, Framingham, MA) provides results in approximately 10 min with sensitivity of 82–95%. The Affirm VPIII (Becton Dickinson, Sparks, MD) is a DNA hybridization probe test that evaluates for T. vaginalis, G. vaginalis, and Candida albicans. The results are available within 45 min; however, sensitivity for trichomonas is only 63%. Trichomonas infection can be diagnosed by visualization of motile trichomonads on wet mount (Fig. 13.4), but alternative tests are preferred since wet mount sensitivity is incredibly low. Trichomoniasis is treated with a single oral dose of metronidazole or tinidazole and requires treatment of exposed sexual partners.

In the case described at the start of this chapter, Sara did not have malodorous discharge or clue cells on wet mount, making BV an unlikely diagnosis. She also did not have thick, cottage cheese-like discharge or green frothy malodorous discharge making VVC and trichomoniasis, respectively, unlikely as well. Sara’s provider did however notice mucopurulent discharge exuding from the cervical os (Fig. 13.5) and endocervical bleeding induced by gentle touch with a swab, known as friability. With these two clinical signs, Sara meets criteria for mucopurulent cervicitis , defined as an inflammation of the cervix with mucopurulent cervical discharge. Patients with gonorrhea or chlamydial cervicitis are frequently asymptomatic though they may experience discharge, dysuria, urinary frequency, dyspareunia (pain with intercourse), or irregular vaginal bleeding most commonly following intercourse. The underlying etiology of mucopurulent cervicitis is frequently unidentified. However, when an underlying cause is determined, Chlamydia trachomatis and Neisseria gonorrhoeae are the most common infections responsible for cervicitis. Less frequently, herpes simplex virus 2 and Trichomonas vaginalis infections can also cause similar clinical signs. Additionally, these same symptoms can be produced by irritation from retained foreign bodies or products like douche or feminine washes.