Lecture 31C and 32 sexually transmitted infections

What increases risk of STI’s

• Number of partners.

• Use of alcohol and other drugs.

Symptoms of STI’s

Abnormal discharge, Pain or burning with urination, sore or blister, swollen lymph nodes in the groin, abnormal vaginal bleeding, severe menstrual cramps, itching in vaginal or rectal area. Pain in the lower abdomen in women, pain during sex. Skin rash or mouth lesions. In females can cause pelvic inflammatory disease.

Pathogenesis of STI’s

Microbes do not survive long in the environment. Intimate contact is required. Enter through mucous membranes of vagina, urethra, rectum and sometimes the mouth and throat.

Treatment for STI’s

Curable with antimicrobial medications but some show resistance. Some antivirals can reduce severity and duration of symptoms

Prevention of STI’s

Abstaining from sex. Having Monogamous relationship with non-infected person. Proper and consistent use of condoms. Circumcision. Vaccine development for HPV.

Gonorrhea

Common among WWI recruits, most common in US. Has become increasing resistance to antibacterial treatments and CDC considers it and urgent threat.

Symptoms of Gonorrhea in men

Pain on urination (urethritis), urethral discharge, complications in urinary flow, infertility and arthritis. Thick pus containing discharge in penis.

Symptoms of Gonorrhea in women

Abnormal vaginal discharge, pain on urination, complications can include pelvic pain, infertility, ectopic pregnancy and arthritis.

Opthalmia neonatorum

Consequence of Gonorrhea, a destructive infection of eye in newborn babies who’s mothers have gonorrhea.

Consequences of Gonorrhea in women

Can develop pelvic inflammatory disease, and ectopic pregnancy due to scar induced blockage of fallopian tubes.

Consequences of Gonorrhea in men

Urinary tract infections, and can cause prostatic abscesses, orchitis, and sterility.

Causative agent of Gonorrhea

Neisseria gonorrhoeae, gram negative diplococcus. Human only, can be cultivated on chocolate agar medium

Pathogenesis of Gonorrhea

Organisms attach to certain non-ciliated epthelial cells by pili; phase and antigenic variation in surface protein and pili allow attachment to different host cells and escape from immune mechanisms; inflammation, scarring, can spread by blood stream

Epidemiology of gonorrhea

Transmitted by sexual contact; asymptomatic infections are common; no immunity following recovery. Oral contraceptives may increase gonorrhea

Treatment for gonorrhea

Combination of antibiotics widespread resistance limits medication.

Prevention for gonorrhea

Abstinence monogamous relationships condoms, early treatment of sexual contacts.

Chlamydial infections

Most common bacterial STIs world wide, resembles gonorrhea as they can cause urethritis and testicles and fallopian tube damage that result in infertility. Attaches to sperm. Can cause PID promoting sterility or ectopic pregnancy. In men can infect epididymis by producing sterility.

Symptoms of Chlamydia in men

Frequently asymptomatic: thin grey white penile discharge, painful testes, painful urination.

Symptoms of Chlamydia in women

Vaginal discharge, vaginal bleeding, abdominal pain, painful urination.

Incubation of chlamydia

Usually 7-14 days.

Causative agent of Chlamydia

Chlamydia trachomatis and obligate intracellular bacterium, certain serotypes (two forms in its life-cycle)

Pathogenesis of chlamydia

The elementary body (EB) attaches to an eptithelial cell and is engulfed by that cell; it becomes a reticulate body in the endosome, where it replicates; the RBs then differentiate into EBs which infect additional host cells when released; tissue damage results form inflammation and the cell-mediated immune response to infection may cause PID and scar tissue in the fallopian tubes; ectopic pregnancy and infertility risk increase.

Epidemiology of chlamydia

The leading reportable bacterial infection United States; large number of asymptomatic infection. Transmitted by vaginal, oral or anal sex.

Treatment for Chlamydia

Appropriate antimicrobial medication

Prevention for chlamydia

Abstinence monogamous relationships correct use of condoms, test sexually active people at least once yearly to rule out asymptomatic infection.

Syphilis

• Major cause of mental illness, blindness, heart disease and stroke.

• Genital sores that enhance the spread of aids.

How was syphilis almost eradicated.

The penicillin treatment, in mid-1950’s.

What factors caused the resurgence of syphilis

Inner-city poverty, drug use and prostitution.

Four clinical stages of syphilis

• Primar syphilis

• Secondary syphilis

• Latent syphilis

• Tertiary syphilis.

Primary syphilis

• Occurs about 3 weeks post infection.

• Painless red ulcer with a hard rime called a hard chancre at site of infection (if external)

• Enlargement of local lymph nodes

• Goes unnoticed in women and homosexual men.

Secondary syphilis

• Appears after 2-10 weeks or longer after the primary stage

• Most infectious

  • Runny nose, watery eyes, sore throat, rash on palms and soles, whitish patches on mucous membranes.

Latent syphilis

• No symptoms of syphilis. Have antibodies to causative agent

• Some recover some remain in this stage

• rest progress to the next stage

Tertiary syphilis

• Long latent period, can last many years.

• Gummas (gummy tumor), damage to blood vessels, mental illness, blindness, stroke, and other nervous system disorders.

• Granulomatous necrotizing mass analogous to tubercle of tuberculosis and can involve any part of the body

• Occurs as a result of hypersensitivity reactions to small number of T pallidum that grown and persist in the tissues

• not infectious.

Causative agent of syphilis

Treponema pallidum, an extremely slender, motile and non-culturable spirochete (grone n the testicles of lab rabbits). Dark-field microscopy is used to see. Is killed by drying and chilling, transmitted exclusively by sexual or oral contact.

Pathogenesis of syphilis

Primary lesion of chancre appears at site of inoculation, heals after 2 to 6 weeks T. pallidum is carried through out the boy in the blood causing fever, rash, mucous membrane lesions, damage to brain arteries and peripheral nerves sometimes years later. Low infectious dose (<100 microbes)

Congenital syphillis

• Fetus can become infected during pregnancy causing miscarriage.

• Some are born

• May develop secondary syphilis which is usually fatal. Cause deformities of face, teeth and other body parts.

Hutchinson’s teeth

notched deformed incisors, a late manifestation of congenital syphilis.

Epidemiology of congenital syphilis

• No animal reservoir.

• Sexual contact with infected partner, kissing, transplacental transmission to fetuses.

Treatment for congenital syphillis

Appropriate antimicrobial medication

Prevention

abstinence, monogamous relationships, correct use of condoms.

Chancroid

• Common bu underreported

• Genital sores that enhance the spread of aids.

Symptoms of chancroid

One or more painful, gradually enlarging soft genital ulcers, tender regional lymph nodes (sometimes pus filled, break open and drain.)

Incubation period of Chancroid

3 to 10 days

Causative agent of chancroid

Haemphilus ducreyi, a pleomorphic fastidious gram-negative rod requiring special growth media.

Pathogenesis of Chancroid

A small pimple appears first which ulcerates and gradually enlargens; multiple lesions may join together; lymph nodes enlarge and may rupture

Epidemiology of chancroid

Sex.

Treatment of chancroid

Appropriate antimicrobial medication

Prevention of Chancroid

Abstinence, monogamous relationships, correct use of condoms.