Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 55 Sexually Transmitted Infections

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins STIs Sexually transmitted infections (STIs) encompass a broad range of infectious diseases that are spread by sexual contact.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Agents of Transmission of Sexually Transmitted Diseases Bacteria Chlamydiae Viruses Fungi Protozoa Parasites Unidentified microorganisms

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Portals of Entry for STDs Mouth Genitalia Urinary meatus Rectum Skin

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Organisms Caused by Some STDs Condylomata acuminata, or genital warts, are caused by the human papillomavirus (HPV). Genital herpes is caused by nine types of herpesviruses, belonging to three groups, which cause infections in humans. Molluscum contagiosum is a common poxvirus. Chancroid is caused by the gram-negative bacterium Haemophilus ducreyi. Granuloma inguinale (i.e., donovanosis, granuloma venereum) is caused by a gram-negative bacillus, Klebsiella granulomatis (previously known as Calymmatobacterium [Donovania] granulomatis).

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Organisms Caused by Some STDs (cont.) Lymphogranuloma venereum (LGV) is an acute and chronic venereal disease caused by Chlamydia trachomatis types L1, L2, and L3.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins STDs Affecting the Mucocutaneous Tissues of the External Genitalia Condylomata acuminata Human papillomavirus (HPV) infection Genital herpes Molluscum contagiosum Chancroid Granuloma inguinale Lymphogranuloma venereum (LGV)

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins AMA Classification Genital Warts (HPV) Condylomata acuminata: cauliflower-shaped lesions that tend to appear on moist skin surfaces (vaginal introitus or anus) Keratotic warts: display a thick, horny layer; develop on dry, fully keratinized skin (penis, scrotum, or labia majora) Papular warts: smooth surface, typically develop on fully keratinized skin Flat warts: macular, sometimes faintly raised, usually invisible to the naked eye, occur on either fully or partially keratinized skin

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Types of Herpesviruses Neurotropic α-group viruses –Herpes simplex virus type 1 –Herpes simplex virus type 2 –Varicella-zoster virus Lymphotropic β-group viruses –Cytomegalovirus –Epstein-Barr virus –Human herpesvirus type 8

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins High-Risk Strains of HPV Infection with some HPV types results in genital warts, cervical dysplasia and cervical cancer. Sexually transmitted infections can selectively infect the mucocutaneous tissues of the external genitalia, cause vaginitis in women, or produce both genitourinary and systemic effects. Some STIs may be transmitted by an infected mother to a fetus or newborn, causing congenital defects or death of the child.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Is the following statement True or False? HPV infections have been implicated in the development of vaginal cancer.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer False Rationale: HPV has been shown to be involved in cervical cancer. Recently, a vaccine, the first cancer vaccine, has been introduced to combat HPV infection.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Pathogenesis of Genital Herpes Infections These viruses replicate in the skin and mucous membranes at the site of infection (oropharynx or genitalia). They grow in neurons and share the biologic property of latency. In genital herpes, the virus ascends through the peripheral nerves to the sacral dorsal root ganglia. During the dormant or latent period, the virus replicates in a different manner so that the immune system or available treatments have no effect on it.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Pathogenesis of Genital Herpes Infections (cont.) Host responses to infection influence initial development of the disease, severity of infection, development and maintenance of latency, and frequency of HSV recurrences.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Diagnosis of Genital Herpes Based on the symptoms Based on appearance of the lesions Identification of the virus from cultures taken from the lesions

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Sexually Transmitted Vaginal Infections Candidiasis Trichomoniasis Bacterial vaginosis

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Candidiasis Causative organism is Candida, yeast-like fungi –Most commonly identified species is Candida albicans. –Candida glabrata and Candida tropicalis have caused symptoms. Present in 20% to 55% of healthy women without causing symptoms –Alteration of the host vaginal environment usually is necessary before the organism can cause pathologic effects.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Causes of Candidiasis Antibiotic therapy –Suppresses the normal protective bacterial flora High hormone levels owing to pregnancy The use of oral contraceptives –Cause an increase in vaginal glycogen stores Diabetes mellitus or HIV infection –Compromise the immune system

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Trichomoniasis Definition –An anaerobic protozoan that feeds on the vaginal mucosa and ingests bacteria and leukocytes Symptoms –Copious, frothy, malodorous, green or yellow discharge –Erythema and edema of the affected mucosa –Occasional itching and irritation –Sometimes strawberry spots appear on the cervix.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Diagnosis of Bacterial Vaginosis At least three of the following characteristics present: –Homogeneous discharge –Production of a fishy, amine odor when a 10% potassium hydroxide solution is dropped onto the secretions –Vaginal pH above 4.5 (usually 5.0 to 6.0) –Appearance of characteristic “clue cells” on wet- mount microscopic studies

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins STDs Infecting Male and Female Genital and Extragenital Structures Chlamydial infections Gonorrhea Syphilis

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Gonorrhea Agent: a pyogenic, gram-negative diplococcus that evokes inflammatory reactions characterized by purulent exudates Host: Humans are the only natural host. Growth: warm, mucus-secreting epithelia Portal of entry: the genitourinary tract, eyes, oropharynx, anorectum, or skin Transmission: heterosexual or homosexual intercourse

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Two Forms of Chlamydiae Elementary bodies –The infectious particles capable of entering uninfected cells Initiator or reticulate bodies –Multiply by binary fission to produce the inclusions identified in stained cells

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Complications from Chlamydia, Gonorrheal, and Syphilis Gonorrheal and chlamydial infections can cause a wide variety of genitourinary complications in men and women, and both can cause ocular disease and blindness in neonates born to infected mothers. Syphilis is caused by a spirochete, T. pallidum. It can produce widespread systemic effects and is transferred to the fetus of infected mothers through the placenta. When syphilis does progress to the symptomatic tertiary stage, it commonly takes one of three forms: development of localized destructive granuloma-like lesions called gummas, development of cardiovascular lesions, or development of central nervous system lesions.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Syphilis Primary syphilis –Appearance of a chancre at the site of exposure Secondary syphilis –Lasts from 1 week to 6 months –Symptoms of a rash fever, sore throat, stomatitis, nausea, loss of appetite, and inflamed eyes Tertiary syphilis –Delayed response of the untreated disease

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Complications from Chlamydia, Gonorrheal, and Syphilis (cont.) When syphilis does progress to the symptomatic tertiary stage, it commonly takes one of three forms: development of localized destructive granuloma-like lesions called gummas, development of cardiovascular lesions, or development of central nervous system lesions.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Treatment Options Chlamydial infections –Azithromycin, doxycycline, amoxicillin Gonorrhea –Tetracycline, penicillin, ceftriaxone, cefixime, ciprofloxacin, ofloxacin, levofloxacin, azithromycin Syphilis –Penicillin

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Of the following conditions, which is known to have neurological implications? −A. Chlamydial infections −B. Gonorrhea −C. Candidiasis −D. Trichomoniasis −E. Syphilis

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer E. Syphilis Rationale: Syphilis will spread to the CNS and cause significant neurological dysfunction.