Sexually Transmitted Diseases:  STD

The incidence of sexually transmitted diseases (STDs), among the most common communicable diseases in the world, steadily increased from the 1950s to the 1970s but generally stabilized in the 1980s. The incidence of some diseases (eg, syphilis and gonorrhea) decreased from the mid-1980s to the mid-1990s in the USA and elsewhere. Nonspecific urethritis, trichomoniasis, chlamydial infections, genital and anorectal herpes and warts (all discussed in this chapter), scabies, pediculosis pubis, and molluscum contagiosum are probably more prevalent than the five historically defined venereal diseases--syphilis, gonorrhea, chancroid, lymphogranuloma venereum, and granuloma inguinale. However, because the latter diseases are more consistently reported, reliable incidence rates for the others are not available.

In 1995, worldwide incidence of gonorrhea was estimated at > 250 million cases (USA, about 400,000); for syphilis, 50 million cases (USA, about 70,000, including about 16,000 primary and secondary cases and 1,500 congenital cases). Chlamydial STDs now approach 1/2 million reported cases annually in the USA, but only an estimated 10 to 20% of all cases are reported. Other infections, including salmonellosis, giardiasis, amebiasis, shigellosis, campylobacteriosis, hepatitis A and B, and cytomegalovirus infection, are transmitted sexually but also by other routes. A strong association between cervical cancer ( and sexually transmitted papillomaviruses exists. Since 1978, HIV has spread rapidly among various populations.

STD incidence rates remain high in most of the world, despite diagnostic and therapeutic advances that can rapidly render patients with many STDs noninfectious and cure most. In many cultures, changing sexual mores and oral contraceptive use have eliminated traditional sexual restraints, especially for women, and both physicians and patients have difficulty dealing openly and candidly with sexual issues. Funding to control STDs is almost uniformly inadequate. Additionally, worldwide dissemination of drug-resistant bacteria (eg, penicillin-resistant gonococci) reflects misuse of antibiotics and spread of resistant clones by mobile populations. The effect of travel is most dramatically illustrated by the rapid spread of the AIDS virus (HIV-1) from Africa to Europe and the Americas in the late 1970s.

STD control depends on good facilities for diagnosis and treatment; locating and treating patients' sexual contacts; following those who received treatment to ensure that they have been cured; educating health care workers and the public; and teaching patients responsible sexual behavior. Despite several decades of effort, effective vaccines for STDs are unavailable outside of clinical trials.

Classification or Types of STD:

• Gonorrhea - Neisseria gonorrhoeae

• Sexually Transmitted Chlamydial, Mycoplasmal & Ureaplasmal Infections - Chlamydia, Mycoplasma & Ureaplasma. (Nongonococcal Urethritis; Nonspecific Urethritis; Mucopurulent Cervicitis; Nonspecific Genital Infections)

• Syphilis - Treponema pallidum

• Trichomoniasis - Infection of the vagina or male genital tract with Trichomonas vaginalis.

• Genital Candidiasis - Candida albicans

• Balanoposthitis - Balanoposthitis or balanitis (in the circumcised) may be a complication of candidiasis, gonococcal or chlamydial urethritis, chancroid, trichomoniasis, herpes simplex, scabies, or primary or secondary syphilis. Noninfectious causes include Reiter's syndrome (balanitis circinata), fixed drug eruptions, contact dermatitis, psoriasis, lichen planus, seborrheic dermatitis, lichen sclerosus et atrophicus, and erythroplasia of Queyrat. Often, no cause can be found. Balanoposthitis is often associated with a tight prepuce, which interferes with adequate hygiene. The subpreputial secretions may become infected with anaerobic bacteria, resulting in inflammation and tissue destruction. Diabetes mellitus predisposes to balanoposthitis, possibly by several mechanisms, including glycosuria.

• Chancroid - Haemophilus ducreyi

• Lymphogranuloma Venereum (Lymphopathia Venereum; Lymphogranuloma Inguinale) - Several immunotypes of Chlamydia trachomatis

• Granuloma Inguinale (Donovanosis) - Calymmatobacterium granulomatis

• Genital Herpes - either of two closely related herpes simplex viruses: HSV-1 or HSV-2.

• Genital Warts - Condylomata Acuminata; Venereal Warts - Human Papillomaviruses - HPV types 6, 11, 16, 18, 31, 33 and 35

• Sexually Transmitted Enteric Infections - Various bacterial (Shigella, Campylobacter or Salmonella), viral (hepatitis A) or parasitic (Giardia or ameba) pathogens are transmitted by sexual practices that promote anal-oral contamination.