For 95-97% of cases, infection is resolved after one dose of metronidazole. Studies suggest that 4-5% of trichomonas cases are resistant to metronidazole, which may account for some “repeat” cases. Without treatment, trichomoniasis can persist for months to years in women, and is thought to improve without treatment in men. Women living with HIV infection have better cure rates if treated for 7 days rather than with one dose.
^ Kissinger P, Mena L, Levison J, Clark RA, Gatski M, Henderson H, et al. (December 2010). "A randomized treatment trial: single versus 7-day dose of metronidazole for the treatment of Trichomonas vaginalis among HIV-infected women". Journal of Acquired Immune Deficiency Syndromes. 55 (5): 565–71. doi:10.1097/qai.0b013e3181eda955. PMC 3058179. PMID 21423852.
^ Epstein, Aaron; Roy, Subir (2010). "Chapter 50: Vulvovaginitis". In Goodwin, T. Murphy (ed.). Management of Common Problems in Obstetrics and Gynecology (5th ed.). Wiley-Blackwell. p. 228. ISBN 978-1405169165. Archived from the original on 2017-02-15. In 80% of cases, the diagnosis of trichomoniasis is confirmed by microscopic examination of saline wet mount, with the observation of motile trichominondas; their shape is "football-like" with moving flagella.