Sexually Transmitted Infections and Male Infertility: Old Enigma, New Insights

Abstract

Sexually transmitted diseases (STDs) are caused by bacteria, viruses, or parasites that are transmitted through venereal contact. The major STDs causing bacterial infections include Chlamydia trachomatis (chlamydiasis), Neisseria gonorrhoeae (gonorrhea), Treponema pallidum (syphilis), Mycoplasma, and Ureaplasma species. On the other hand, the major viral STD infections include herpes simplex virus (HSV), human papillomavirus (HPV), human immunodeficiency virus (HIV), human cytomegalovirus (HCV), and hepatitis B and C viruses. Similarly, the major parasite infecting the genital tract is the protozoan Trichomonas vaginalis, which causes trichomoniasis. In males, these STDs may either be asymptomatic or cause urethritis, epididymitis, orchitis, vasiculitis, and prostatitis. Most of these infections have been shown to affect male fertility by affecting semen parameters like sperm count, motility, and morphology; however, their exact mechanism of action is still not known. The presence of infection(s) on sperm and/or in the seminal plasma causes their horizontal transmission to sexual partners and vertical transmission to offsprings. This chapter briefly reviews some of the published literature on major STDs in relation to male infertility and relevant treatment strategies. (CDRI communication number 9456)