Fungal Reproductive System Diseases
Protozoan Sexually Transmitted Diseases
Trichomoniasis, a common STD, is caused by an infection with a protozoan, unicellular protist called Trichomonas vaginalis. The parasite is often a benign resident of the vaginal microbiota that spreads during sex. When the normal microflora of the vagina is disrupted, Trichomonas vaginalis can opportunistically spread.
Some T. vaginalis strains are more virulent than others, possessing virulence factors that aid in movement, adhesion, and spread in the reproductive system. They infect the vulva, vagina, cervix, or urethra in women and urethra in men. It usually does not infect other body parts such as the anus, mouth, or hands. Only 30% of people who are infected show any symptoms of the infection. Symptoms for women are genital itching, burning or redness, pain during urination, and abnormal vaginal discharge. For men, itching or irritation inside the penis, burning after ejaculation or urination, inflammation, and discharge from the penis are all symptoms of trichomoniasis.
Diagnosis is made by testing a sample of discharge from the patient—vaginal fluid for women and urine for men—for the presence of T. vaginalis DNA. Using condoms lowers the risk of getting trichomoniasis but does not completely eliminate it since trichomoniasis can infect areas not covered by condoms. Trichomoniasis can be treated with the oral antibiotics metronidazole or tinidazole.