The Persistent Parasite: Diagnosis and Treatment of Resistant Trichomonas vaginalis Infection

Trichomonas vaginalis affects 5.3% of women globally.1 It is associated with multiple adverse outcomes including pelvic inflammatory disease, infertility, HIV and sexually transmitted infection (STI) acquisition/transmission, cervical cancer and adverse birth outcomes.1 5-nitroimidazoles (metronidazole [MTZ], tinidazole [TDZ], secnidazole [SEC]) are the only drug class approved for treatment.2 MTZ became available in 1960, with reports of drug resistance emerging 2 years later.1 TDZ and SEC drug-resistant cases have also been published.1 Diagnosing and treating resistant T. vaginalis is challenging, particularly during pregnancy. There are no population-based data on the prevalence of 5-nitroimidazole drug resistance, with most data coming from case studies, case series and small observational studies. Resistance prevalence ranges from 2% to 10% among diverse populations.1 However, the criteria used to define resistance across studies vary, limiting the ability for comparisons. Additionally, most studies are over a decade old. Updated 5-nitroimidazole resistance data among clinical T. vaginalis isolates …