Guideline sources The following summarized guidelines for the evaluation and management of trichomonas vaginalis infection are prepared by our editorial team based on guidelines from the Center for Disease Control (CDC 2021), the American College of Obstetricians and Gynecologists (ACOG 2020), the International Union Against Sexually Transmitted Infections (IUSTI/WHO 2018), and the Society of Obstetricians and Gynaecologists of Canada (SOGC 2015). 1 2 3 4 Pathway Trichomonas vaginalis infection Diagnosis and management Guidelines 1. Diagnostic investigations Initial evaluation: https://web.pathway.md/diseases/recP9PTfotCL2W1vj 1/3 6/24/23, 4:09 PM Trichomonas vaginalis infection Pathway As per IUSTI 2018 guidelines, obtain nucleic amplification tests for the diagnosis of Trichomonas vaginalis. A As per SOGC 2015 guidelines, obtain antigen testing (immunoassay or NAAT) using vaginal swabs to detect Trichomonas vaginalis. B 2. Medical management Antibiotic therapy: As per CDC 2021 guidelines, administer metronidazole 500 mg PO BID for 7 days as first-line therapy in female patients with trichomoniasis. E Show 2 more As per IUSTI 2018 guidelines, administer nitroimidazoles (metronidazole or tinidazole) as first- line therapy in patients with trichomoniasis: Situation Guidance 400-500 mg PO BID for 5-7 days Metronidazole 2 g PO in a single dose Metronidazole 2 g PO in a single dose. A Tinidazole As per SOGC 2015 guidelines, administer oral metronidazole 2 g PO as a one-time dose or 500 mg PO BID for 7 days for the treatment of patients with trichomoniasis. A Management of persistent/recurrent disease: As per IUSTI 2018 guidelines, administer repeated course of nitroimidazole at a higher dose in patients with persistent and recurrent trichomoniasis. B As per SOGC 2015 guidelines, consider administering higher-dose metronidazole therapy in patients with treatment-resistant trichomoniasis. B Management of sexual partners: as per IUSTI 2018 guidelines, offer treatment for sexual partners of patients diagnosed with trichomoniasis. A 3. Specific circumstances Pregnant patients: As per IUSTI 2018 guidelines, administer metronidazole for the treatment of trichomoniasis in pregnant patients. A As per SOGC 2015 guidelines, administer oral metronidazole in pregnant patients with symptomatic trichomoniasis in order to reduce the risk of preterm birth. A https://web.pathway.md/diseases/recP9PTfotCL2W1vj 2/3 6/24/23, 4:09 PM Trichomonas vaginalis infection Pathway Patients with HIV: administer metronidazole 500 mg PO BID for 7 days in human immunodeficiency virus-infected female patients with trichomoniasis. E 4. Follow-up and surveillance Post-treatment testing: as per SOGC 2015 guidelines, do not obtain tests of cure following treatment of trichomoniasis with oral metronidazole. D Likelihood Ratios Pertinent positives The following findings increase the probability of trichomonas vaginalis infection in adults. -1 Finding LR+ Value Presence of trichomonads 46 (17-121) Pertinent negatives The following findings decrease the probability of trichomonas vaginalis infection in adults. -1 Finding LR- Value Absence of trichomonads 0.50 (0.36-0.71) References 1. Sherrard J, Wilson J, Donders G et al. 2018 European IUSTI/WHO International Union against sexually transmitted infections IUSTI World Health Organisation WHO guideline on the management of vaginal discharge. Int J STD AIDS. 2018 Nov;29 13 1258 1272. Open 2. No authors listed. Vaginitis in Nonpregnant Patients: ACOG Practice Bulletin, Number 215. Obstet Gynecol. 2020 Jan;135 1):e1-e17. Open 3. van Schalkwyk J, Yudin MH, INFECTIOUS DISEASE COMMITTEE. Vulvovaginitis: screening for and management of trichomoniasis, vulvovaginal candidiasis, and bacterial vaginosis. J Obstet Gynaecol Can. 2015 Mar;37 3 266 274. Open 4. Kimberly A Workowski, Laura H Bachmann, Philip A Chan et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021 Jul 23;70 4 1 187. Open 5. US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC et al. Screening USPSTF for Gynecologic Conditions With Pelvic Examination US Preventive Services Task Force Recommendation Statement. JAMA. 2017;317 9 947 953. Open 6. Jack D Sobel, MDCaroline Mitchell, MD et al. Trichomoniasis. UpToDate; Trichomoniasis. Open https://web.pathway.md/diseases/recP9PTfotCL2W1vj 3/3