The most appropriate additional management is to treat the patient's sexual partner for trichomoniasis. Trichomoniasis, which is caused by Trichomonas vaginalis, is the most common nonviral sexually transmitted infection (STI) worldwide. Unlike other STIs that predominate in adolescents and younger adults, rates of trichomoniasis are evenly distributed among women of all age groups. It is caused by motile flagellated protozoa that infect the urogenital tract, causing inflammatory vaginitis and urethritis. Treatment with a single 2-g dose of metronidazole is associated with a high rate of cure and should be offered to all symptomatic women, including pregnant women. Because of the high rate of reinfection among women treated for trichomoniasis (17% within 3 months in one study), retesting for T. vaginalis is recommended by the Centers for Disease Control and Prevention (CDC) for all sexually active women within 3 months after initial treatment, regardless of whether they believe their sexual partners were treated. Testing by nucleic acid amplification can be conducted as soon as 2 weeks after treatment. It is important that sexual partners also be treated, even if they are asymptomatic; documentation of infection is not required before treatment in any partners. Data are insufficient to support retesting men after treatment for trichomoniasis. T. vaginalis infection is associated with a two- to threefold increased risk for HIV acquisition. Therefore, the CDC recommends that testing for other STIs, including HIV, be performed in persons infected with T. vaginalis.
Pap testing is not needed for management of trichomoniasis because the infection is not associated with cervical malignancy.
Because of the high rate of partner infection with T. vaginalis and its association with other STIs, it would be inappropriate to not provide further testing or intervention after a primary T. vaginalis diagnosis.