Trichomonas vaginalis infection Diagnosis and management Initial evaluation Obtain antigen testing (immunoassay or NAAT) using vaginal swabs to detect Trichomonas vaginalis. B Pregnant patients SOGC Q Is the patient pregnant? No 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 Yes Administer oral metronidazole in pregnant patients with symptomatic trichomoniasis in order to reduce the risk of preterm birth. A Management of persistent/recurrent disease SOGC Q Does the patient respond to oral metronidazole? Yes Consider administering higher-dose metronidazole therapy in patients with treatment- resistant trichomoniasis. B Post-treatment testing Do not obtain tests of cure following treatment of trichomoniasis with oral metronidazole. D No Do not obtain tests of cure following treatment of trichomoniasis with oral metronidazole. D