Trichomoniasis in adolescents

September 1, 2011

Less than half of pediatricians report routine STI screening for their sexually active patients.

Key Points

Pathophysiology

Trichomoniasis is caused by T vaginalis, a flagellated protozoon that colonizes only human hosts and infects both the female and male urogenital systems.1 Sites of colonization commonly include the vagina, Bartholin glands, Skene's glands, the urethra, and the prostate. Transmission is through sexual contact, although occasional perinatal transmission has been reported.2 This motile parasite can appear round, pear shaped, or oval and can take on an ameboid shape when it adheres to epithelial cells.1 Adherence is essential to pathogenesis and is facilitated by the presence of iron and a higher pH, an environment common during menses. Once adhered to epithelial cells, not only do trichomonads release proteases and glycoproteins that produce an intense inflammatory response from the host, but they also are capable of reducing the number of lactobacilli in their environment, raising pH and prolonging their survival.

Risk of sexually transmitted viruses

Significant health consequences result from trichomoniasis. The intense inflammatory response is thought to play a role in both acquisition and transmission of sexually transmitted viruses. One study showed that women with newly diagnosed trichomoniasis were almost 4 times as likely as noninfected controls to acquire herpes simplex virus type 2 (HSV-2) during the study period.5

A more concerning and potentially deadly fact is that infection with and transmission of the human immunodeficiency virus (HIV) is increased for women infected with T vaginalis. A study in African women showed that women with trichomoniasis are more likely to acquire HIV infection.6 A recent study of HIV-positive women in New Orleans showed that infection with T vaginalis increases the vaginal shedding of HIV infection and that treatment of trichomoniasis resulted in less HIV shedding.7

Adolescent women with human papillomavirus (HPV) are more likely to have persistent infection of this virus if they also have trichomoniasis. Evidence of delayed clearance of HPV was identified in a study carried out in Indianapolis that showed that average time to clearance of HPV infection in adolescents occurred in 172 days in girls without trichomoniasis but took more than twice as long (average, 436 days) for those with concurrent trichomoniasis infection.8