Sexually Transmitted Diseases

Agents of Transmission of Sexually Transmitted Diseases
Bacteria
Chlamydiae
Viruses
Fungi
Protozoa
Parasites
Unidentified microorganisms
Portals of Entry for STDs
Mouth
Genitalia
Urinary meatus
Rectum
Skin
STDs Affecting the Mucocutaneous Tissues of the External Genitalia
Human papillomavirus (HPV) infection
Genital herpes
Molluscum contagiosum
Chancroid
Granuloma inguinale
Lymphogranuloma venereum (LGV)

AMA Classification Genital Warts
Condyloma 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
Types of Herpesviruses
Neurotropic α-group viruses
Herpes simplex virus type 1
HSV-2
Varicella-zoster virus
Lymphotropic β-group viruses
Cytomegalovirus
Epstein-Barr virus
Human herpesvirus type 8

Diagnosis of Genital Herpes
Based on the symptoms
Based on appearance of the lesions
Identification of the virus from cultures taken from the lesions
Anti-Viral Drugs and Their Actions
Drugs
Acyclovir, Valacyclovir, Famciclovir
Actions
Interfere with viral DNA replication
Decrease the frequency of recurrences
Shorten the duration of active lesions
Reduce the number of new lesions formed
Decrease viral shedding with primary infections
Sexually Transmitted Vaginal Infections
Candidiasis
Trichomoniasis
Bacterial vaginosis
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
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
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.

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
STDs Infecting Male and Female Genital and Extragenital Structures
Chlamydial infections
Gonorrhea
Syphilis
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
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
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