Is Trichomonas a Sexually Transmitted Infection?
Yes, Trichomonas vaginalis is definitively classified as a sexually transmitted infection (STI). 1, 2, 3
Classification and Transmission
The CDC explicitly categorizes trichomoniasis as a sexually transmitted disease with potentially serious sequelae, requiring simultaneous treatment of sexual partners to prevent reinfection. 3
The infection is highly contagious between sexual partners, with approximately 72% of male partners of infected women testing positive for concordant infection. 4
Women who have never been sexually active are rarely affected, supporting the sexual transmission route. 1
Clinical Significance as an STI
The classification as an STI is reinforced by several key characteristics:
Trichomoniasis facilitates HIV transmission and acquisition, increases risk of cervical cancer, and causes adverse pregnancy outcomes including preterm delivery and low birth weight. 2, 5
The infection affects an estimated 3.7 million people in the United States, making it likely the most prevalent non-viral STI. 5
Significant health disparities exist, with African Americans being more than 4 times more likely to be infected than other racial groups. 5
The "Hidden Reservoir" Problem
Approximately 80% of infected men are asymptomatic, creating a substantial reservoir for ongoing transmission without their knowledge. 6, 2
Up to 50% of infected women may also be asymptomatic, further complicating transmission control. 1, 2
This high rate of asymptomatic infection in both sexes makes screening and partner notification critical public health interventions. 6
Partner Management Requirements
Concurrent testing and treatment of all sexual partners is mandatory to prevent reinfection, as reinfection rates are extremely high when partners are not treated simultaneously. 2, 3
Patients must abstain from sexual activity until both they and their partners complete treatment and are asymptomatic. 2