Sexually Transmitted Infections

Bacterial Diseases of the Reproductive Systems

• Chlamydia trachomatis causes NGU (nongonococcal urethritis), which is characterized by painful urination and a watery discharge.
• C. trachomatis can be transmitted to infants' eyes at birth.
• Diagnosis is based on detection of chlamydial DNA in urine.
• Ureaplasma urealyticum and Mycoplasma genitalium also cause NGU.

Syphilis

• Caused by Treponema pallidum, a gram-negative spirochete.
• Primary stage: initial sign is a small, hard-based chancre, or sore.
• Bacteria enter the bloodstream and lymphatic system, distributing them widely in the body.
• Secondary stage: oral sores and skin rashes, loss of patches of hair, malaise, and mild fever.
• Tertiary stage: affects many tissues and organs.
• Congenital syphilis: results from T. pallidum crossing the placenta during the latent period, causing neurological damage in the newborn.
• Syphilis is transmitted by sexual contact and can be treated with antibiotics.

Bacterial Vaginosis

• Caused by Gardnerella vaginalis, which decreases the number of vaginal Lactobacillus.
• Diagnosis is based on the presence of clue cells.
• Treatment is primarily by metronidazole.

Viral Diseases of the Reproductive Systems

Genital Herpes

• Caused by herpes simplex viruses (HSV-1 and HSV-2).
• Symptoms: painful urination, genital irritation, and fluid-filled vesicles.
• The virus might enter a latent stage in nerve cells, and vesicles reappear following trauma and hormonal changes.
• Neonatal herpes: contracted during fetal development or birth, resulting in neurological damage or infant fatalities.
• Diagnosis: culture of the virus from a vesicle, PCR.
• No cure, but treatment is available with antiviral drugs, such as acyclovir, famciclovir, and valacyclovir.

Genital Warts

• Caused by human papillomaviruses (HPV).
• Serotypes 6 and 11 cause visible genital warts, while types 16 and 18 cause cervical cancer.
• Disease is transmitted sexually.
• Available methods, such as surgery or cryotherapy, are not as effective against genital warts.

Fungal Disease of the Reproductive Systems

Candidiasis

• Caused by Candida albicans, which causes nongonococcal urethritis in men and vulvovaginal candidiasis, or yeast infection, in women.
• Symptoms: lesions that produce itching and irritation.
• Predisposing factors: pregnancy, diabetes, and broad-spectrum antibacterial chemotherapy.
• Diagnosis is based on observation of the fungus and its isolation from lesions.
• Treatment: topical application of antifungal drugs, such as clotrimazole and miconazole.

Protozoan Disease of the Reproductive Systems

Trichomoniasis

• Caused by the anaerobic protozoan Trichomonas vaginalis.
• Symptoms: greenish yellow discharge with a foul odor, irritation, and itching.
• Diagnosis is based on observation of the protozoa in purulent discharges from the site of infection.
• Treatment is by oral metronidazole.

Structure and Function of the Reproductive Systems

• The female reproductive system consists of two ovaries, two uterine tubes, the uterus, the cervix, the vagina, and the external genitals.
• The ovaries produce female sex hormones and ova (eggs).
• The male reproductive system consists of two testes, ducts, accessory glands, and the penis; seminal fluid leaves the male body through the urethra.

Bacterial Diseases of the Reproductive Systems

Gonorrhea

• Caused by Neisseria gonorrhoeae, a gram-negative diplococcus.
• Symptoms in men: painful urination and pus discharge.
• Blockage of the urethra and sterility are complications of untreated cases.
• Women may be asymptomatic unless the infection spreads to the uterus and uterine tubes.
• Complications: gonorrheal endocarditis, gonorrheal meningitis, and gonorrheal arthritis.
• Ophthalmia neonatorum: an eye infection acquired by infants during passage through the birth canal of an infected mother.
• Diagnosis: ELISA or Nucleic acid amplification tests (NAATs).
• Treatment: antibiotics.

Bacterial Diseases of the Urinary System

Cystitis

• Inflammation of the urinary bladder, common in females.
• Symptoms: dysuria (difficult, painful, urgent urination) and pyuria.
• The female urethra is less than 2 inches long, making it closer to the anus and its contaminating intestinal bacteria.
• Most common etiologies: E. coli and Staphylococcus saprophyticus.
• Diagnosis: isolation and identification of bacteria.
• Treatment: antibacterial drugs.

Pyelonephritis

• Inflammation of the kidneys, usually a complication of lower urinary tract infections.
• Symptoms: fever and flank or back pain.
• About 75% of pyelonephritis cases are caused by E. coli.
• Pyelonephritis generally results in bacteremia.
• Diagnosis: blood cultures and a Gram stain of the urine for bacteria.
• Treatment: broad-spectrum antibiotics, such as second- or third-generation cephalosporin.

Leptospirosis

• Primarily a disease of domestic or wild animals, but can be transmitted to humans and cause severe kidney or liver disease.
• Caused by the spirochete Leptospira interrogans.
• Disease is transmitted to humans by contact with urine-contaminated water.
• Symptoms: chills, fever, headache, and muscle aches.
• An emerging form of leptospirosis is pulmonary hemorrhagic syndrome, with a fatality rate of 50%.
• Diagnosis: serological test.
• Treatment: doxycycline (tetracycline).