Is Research on Trichomonfasis Commensurate Wkh the Prevalence of Thfs Std?

Number 20 Last year I wrote a two-part essay on herpes simplex virus infections. 1z In it, I noted that although herpes has been known for over 2,000 years, it has only recently attracted the attention of medical researchers. But herpes, specifically HSV2, is just one of several sexually transmitted diseases (STDS) whose incidence has recently reached dramatic levels. This " new generation " of STDS, as they are popularly labeled, includes not only genital herpes, but also nongon-ococcal urethritis (an inflammation of the urethra not due to gonorrhea), pelvic inflammatory disease, candidiasis (a vaginal yeast infection), and tricho-moniasis.s.'l Although they have probably existed since antiquity, they are " new " in the sense that modem laboratory techniques to discover their prevalence , method of transmission, and health consequences have only recently been developed.3 By far the most widespread of the new STDS is trichomoniasis. The incidence and virulence of trichomoniasis in men is currently a matter of dispute in the scientific community. But this heretofore little-known disease, still often unreported by public health agencies, s is estimated to occur in over 50 percent of women with abnormal vaginal discharges , ~ or about 20 percent of the female population of the US.' In fact, the Centers for Disease Control estimates that there are three million new cases of trichomoniasis each year, thereby surpassing the incidence of syphilis, gonor-This essay examines the etiology and epidemiology of trichomoniasis, and the controversy surrounding its diagnosis and treatment. Trichomoniasis, a chronic disease of the urogenital tract, affects both men and women.4 It is caused by a protozoan of the genus Tn " chomona.r, a common parasite in the digestive systems of many animals. Humans may host three species of trichomonad: Perrtatn'chomorsa~ hom-inis, in the intestine; Tn " chotrronas tenax, in the mouth; and Trichomonas vaginal-i.r, in the vagina or the male urethra. 6S T. vaginalis is the only species known to cause disease, possibly due to a tozin it produces which causes an inflammatory response.g The symptomatology of trichomonia-sis is somewhat difficuh to characterize. Clinical manifestations of the disease in the female urogenital system differ from those presented by the male. But symptoms vary even among patients of the same sex, since different strains of T. vaginalis seem to have different pathogenic capabilities. Symptoms may even worsen and improve repeatedly in the same patient. Consequently, while trichomoniasis in women is usually characterized by …