This sexually transmitted disease is not reportable, so the epidemiologic data remains very difficult to obtain. However, it has been estimated that there are 5 million new cases in the United States each year, which is more than the sum of all cases of Chlamydia and gonococcal infections. The World Health Organization estimates that there is incidence of 173 million new infections of Trichomoniasis worldwide per year. This is also known as Trichomonas vaginitis. It is caused by the sexually transmitted, flagellated parasite, Trichomonas vaginalis. The transmission rate is high; 70% of men contract the disease after a single exposure to an infected woman, which suggests that the rate of male-to-female transmission is even higher. The parasite, which exists only in trophozoite form, is an anaerobe that has the ability to generate hydrogen to combine with oxygen to create an anaerobic environment. It often accompanies bacterial vaginosis, which can be diagnosed in as many as 60% of patients with Trichomonas vaginitis (Cates, Jr., 1999, S2-S7).
Risk Factors: There are certain risk factors that are associated with Trichomoniasis. These include all the risk factors for sexually transmitted infection acquisition. ...
There is generally a longer duration of infectiousness and a high level of asymptomatic infections, especially in men. Many women with annual Pap smear examination have asymptomatic infections. This is responsible for 25% of all cases of clinically diagnosed vaginitis. More than half of infected women and nearly 90% of infected men are asymptomatic, which increases the reservoir of people spreading the infection. Trichomoniasis increases the risks of human immunodeficiency virus (HIV) transmission and HIV acquisition (Horowitz, Mrdh, eds., 1999).
Infection: The primary mode of transmission of T. vaginalis is through sexual contact. Transmission by fomites is possible, but is rarely the cause of a symptomatic infection. An inoculums of at least 10,000 organisms is needed to establish a clinically significant infection. Male-to-female transmission rates are higher than female-to-male rates; about 85% of exposed women will contract the infection. Female-to-male transmission rates are more variable, but may be as high as 70% within 48 hours of exposure. Incubation period varied between 4 to 28 days. T. vaginalis resembles anaerobic bacteria more than eukaryotic behavior in that it ferments large amounts of carbohydrates into carbon dioxide and hydrogen gases, causing bubbles. Its presence in the vaginal vault changes the vaginal microbiology-the lactobacilli disappear and anaerobic bacteria predominant. T. vaginalis swims freely in the vaginal discharge but can also attach to the vaginal wall. The cell membranes of the parasite and those of the host interdigitate. Trichomonas adhere to vaginal and cervical epithelial cells. T. vaginalis also infects the urethra, Skene's glands, and Bartholin glands. The