Sexually Transmitted Diseases

2005-02

Sexually Transmitted Diseases

Impact Common Infectious Agents Symptoms Pathogenesis Diagnosis Treatment

Impact 19 million new cases/yr in USA Major part of health care budget Major part of medical practice Serious side effects

Infertility Premature birth Cesarian sections Birth defects Neonatal disease Death

Incidence and Prevalence STD Incidence Prevalence Chlamydia 2,800,000 N.R. Gonorrhea 700,000 N.R. Syphilis 32,000 N.R. Herpes (HSV) 1,000,000 45,000,000 Hepatitis B 60,000 1,250,000 Genital Warts (HPV) 6,200,000 20,000,000 Trichomoniasis 7,400,000 N.R.

15-24 year-old

Common Features

Human only Transmission Virulence Mechanism

Inapparent Infection Prevention

Abstinence Monogamy

Two Major Presentations

“Drips” Urethritis

Gonorrhea Non-gonoccal urethritis

Vaginal discharge Trichomoniasis

“Bumps” Warts Swollen lymph glands

AIDS Chancroid Lymphogranuloma

venereum (LGV)

Genital ulcer disease Herpes Syphilis Chancroid LGV

STD’s

Most commont Non-gonococcal urethritis Gonorrhea Genital herpes Genital warts Trichomoniasis

Less common AIDS Syphilis

Uncommon Chancroid LGV

STD overview

Encounter Genital contact Blood

Entry External genitalia Mucosal membrane (genital, anal or oral)

Spread Mucosal surface (local) Systemic

Multiplication - most fastidious Neisseria gonorrhoeae: Thayer-Martin Chlamydia trachomatis: obligate intracellular Treponema pallidum: can not be cultured in vitro

STD overview

Host defenses Non-specific mucosal defense Recruit phagocyte during infection sIgA Phagocyte and complement (systemic)

Damage Inflammation leading to scarring Intracellular cytotoxicity (Chlamydia)

Spread to new hosts Sexual contact Neonatal or congenital Blood

Gonorrhea

Many asymptomatic Reason for spread

Male- Urethritis, urethral discharge Female - Endocervicitis, discharge, dysuria, bleeding Pharyngitis Proctitis Disseminated gonococcal infection (DGI)

Pustular skin lesions Septic arthritis

Pelvic inflammatory disease (PID) Endometritis, salpingitis, peritinitis Infertility, ectopic pregnancy

Ophthalmia neonatorum

Neisseria gonorrhoeae Gram-, diplococcus

Gram stain pus, intracellular diplococcus Virulence factors

Pili Initial attachment Antigenic and phase variation

Opacity protein (Opa) Tighter contact and invasion Antigenic variation

LOS (lipooligosaccharide, lack O-Ag) Inflammatory, major cause of symptom

IgA protease

Pili antigenic variation

Phase variation

Opa

PilC

N. gonorrhoeae

Gonorrhea

Diagnosis Intracellular Gram negative diplococci in

discharge Growth on selective media, oxidase positive

colonies Fluorescent antibody

Treatment Cover for probable association with C. trachomatis

Non-gonococcal Urethritis

Infectious agents Chlamydia trachomatis Ureaplasma urealyticum

Symptoms of Chlamydial infection Often inapparent in men Watery or mucopurulent discharge Dysuria In women, mucopurulent cervicitis, salpingitis,

premature labor In newborns may cause conjunctivitis or

pneumonia

Chlamydia trachomatis

G- type, no peptidoglycan Obligate intracellular

Energy parasite - ATP Evade phagocytosis and complement

Disease resembles neisseriae Urethritis Cervicitis, salpingitis, PID Infant pneumonia Conjunctivitis Lymphogranuloma venereum (LGV)

Damage Cytotoxicity, necrosis, scarring

C. trachomatis

Life cycle Elementary body

Resistant to extracellular environment

Do not reproduce in this form Infectious

Reticulate body Replicative form Form inclusion body in vacuole Not infectious Converts into EB and release

C. trachomatis

Infection of epithelial cells Male - Urethra Female - cervix, endometrium or fallopian tubes

LPS mediated inflammation Alternative complement pathway Activate macrophage to produce TNF and IL-8

which is chemotactic to PMNs Tissue damage

Tissue repair after the infection is resolved Scarring

C. trachomatis

Diagnosis – grow in fibroblasts, detect with

flourescein-labeled antibody PCR

Treatment Keep in mind – no peptidoglycan

Other Common STD’s Genital herpes

Caused by HHV 1 Causes painful ulcers and (with a primary infection)

asceptic meningitis Can be treated with acyclovir

Genital warts Caused by papilloma virus May cause cervical cancer

Trichomoniasis Caused by Trichomonas vaginalis Asymptomatic in men Causes severe vaginal itching and a blood-tinged discharge

in women Treated with metronidazole

Haemophilus ducreyi

G- cocco-bacillus Genital ulcers

Chancroid - soft chancre Painful Unindurated Potentiates the spread of HIV

Uni- or bilateral lymphadenopathy

Treponema pallidum

Spirochetes that do not Gram stain Dark field or fluorescent microscopy Endoflagellum

Stages of Syphilis

Syphilis Primary syphilis

Chancre on primary infection sites External genitalia, perianal, lips or gums

Secondary syphilis Generalized skin rash - palm and sole Fever, malaise and headache

Latent syphilis Asymptomatic and non-infectious

Tertiary syphilis (4-10 years after secondary) Gumma (granulomatous dermal lesions) Neurosyphilis

Paresis, blindness, neurological signs Cardiovascular syphilis Delayed type hypersensitivity - immune response

Primary Syphilis -- chancre

Secondary Syphilis -- rash

Syphilis

Congenital syphilis Infection via blood and placenta Similar to secondary syphilis Mortality rate 25%

Treatment Primary and secondary

Penicillin or doxycycline

Tertiary syphilis Antimicrobial not effective

Congenital syphilis Penicillin treatment

Diagnosis

Detection of the organism in lesions Serology

Indirect: anti-cardiolipin VDRL: Venereal Disease Research Laboratory RPR: Rapid Plasma Reagin

Direct: anti-treponemal Ab FTA-ABS: Fluorescent treponemal antibody

adsorption MHA-TP: Microhemagglutination test for T.

pallidum

Nucleic acid amplification tests