Diseases of the Genitourinary Tract: Microbiology Study Guide

Diseases of the Genitourinary Tract

Basic Anatomy of the Urinary System

The urinary system is responsible for the removal of waste products from the blood and maintaining water and electrolyte balance. It consists of:

• Kidneys: Filter blood and produce urine.

• Ureters: Transport urine from kidneys to bladder.

• Bladder: Stores urine until excretion.

• Urethra: Conducts urine out of the body.

Basic Anatomy of the Male and Female Reproductive Systems

The reproductive systems are involved in sexual reproduction and hormone production.

• Male: Testes, epididymis, vas deferens, seminal vesicles, prostate gland, penis.

• Female: Ovaries, fallopian tubes, uterus, vagina, vulva.

Urinary System Diseases

Cystitis

Cystitis is inflammation of the urinary bladder, commonly caused by Escherichia coli and Staphylococcus saprophyticus.

• Signs/Symptoms: Dysuria (painful urination), increased frequency, urgency, cloudy urine.

• Treatment: Antibiotics such as trimethoprim-sulfamethoxazole.

• Prevention: Good hygiene, urinating after intercourse.

Pyelonephritis

Pyelonephritis is infection of the kidneys, often resulting from untreated cystitis.

• Organism: Usually Escherichia coli.

• Signs/Symptoms: Fever, back pain, chills, nausea.

• Treatment: Extended antibiotic therapy.

Leptospirosis

Leptospirosis is a zoonotic disease caused by Leptospira interrogans.

• Transmission: Contact with water contaminated by animal urine.

• Signs/Symptoms: Fever, headache, muscle pain, jaundice.

• Treatment: Doxycycline or penicillin.

• Prevention: Avoiding contaminated water.

Reproductive System Diseases

Chlamydia

Chlamydia is caused by Chlamydia trachomatis, the most common bacterial STD.

• Signs/Symptoms: Often asymptomatic; can cause urethritis, pelvic pain, discharge.

• Complications: Trachoma (eye infection), Pelvic Inflammatory Disease (PID) if untreated.

• Treatment: Antibiotics (azithromycin, doxycycline).

Gonorrhea

Gonorrhea is caused by Neisseria gonorrhoeae.

• Signs/Symptoms: Painful urination, pus-like discharge.

• Complications: Ophthalmia neonatorum (eye infection in newborns).

• Treatment: Antibiotics (ceftriaxone).

Pelvic Inflammatory Disease (PID)

PID is a collective term for infection of female pelvic organs, often caused by Chlamydia trachomatis or Neisseria gonorrhoeae.

• Complications:

  • Salpingitis: Infection of fallopian tubes.

  • Ectopic pregnancy: Fertilized egg implants outside uterus due to tubal damage.

• Signs/Symptoms: Abdominal pain, fever, irregular bleeding.

• Treatment: Broad-spectrum antibiotics.

Syphilis

Syphilis is caused by Treponema pallidum, a spirochete bacterium.

• Stages:

  • Primary stage: Painless chancre at infection site.

  • Secondary stage: Skin rashes, mucous membrane lesions.

  • Latent period: No symptoms; can last years.

  • Tertiary stage: Severe complications: gummatous syphilis (soft tissue lesions), cardiovascular syphilis, ocular syphilis, neurosyphilis.

• Congenital syphilis: Transmitted from mother to fetus; can cause stillbirth, deformities, neurological damage.

• Treatment: Penicillin.

Bacterial Vaginosis

Bacterial vaginosis is caused by an imbalance of vaginal flora, often Gardnerella vaginalis.

• Signs/Symptoms: Thin, gray vaginal discharge, fishy odor.

• Treatment: Metronidazole.

Candidiasis

Candidiasis (yeast infection) is caused by Candida albicans.

• Signs/Symptoms: Thick, white discharge, itching, irritation.

• Treatment: Antifungal agents (fluconazole).

Trichomoniasis

Trichomoniasis is caused by the protozoan Trichomonas vaginalis.

• Signs/Symptoms: Frothy, greenish discharge, itching.

• Treatment: Metronidazole.

Genital Herpes

Genital herpes is caused by Herpes simplex virus (HSV-2, sometimes HSV-1).

• Signs/Symptoms: Painful vesicles, ulcers.

• Latency: Virus remains dormant in nerve cells; recurrences triggered by stress, illness.

• Treatment: Antivirals (acyclovir).

Genital Warts

Genital warts are caused by Human papillomavirus (HPV).

• Signs/Symptoms: Warty growths on genitalia.

• Complications: Some HPV types cause cervical cancer.

• Treatment: Removal (cryotherapy, topical agents).

• Prevention: HPV vaccine.

AIDS (Acquired Immunodeficiency Syndrome)

AIDS is caused by Human Immunodeficiency Virus (HIV).

• Transmission: Blood, sexual contact, mother-to-child.

• Stages of HIV infection:

  • Acute phase: Flu-like symptoms, high viral load.

  • Chronic phase: Asymptomatic or mild symptoms; gradual decline in CD4+ T cells.

  • AIDS: Diagnosed when CD4+ T cell count < 200 cells/µL or opportunistic infections occur.

• Prevention: Safe sex, needle exchange, antiretroviral therapy, screening blood products.

Summary Table: Major Genitourinary Diseases

Disease	Organism	Signs/Symptoms	Treatment	Prevention
Cystitis	Escherichia coli, Staphylococcus saprophyticus	Dysuria, urgency	Antibiotics	Hygiene
Pyelonephritis	Escherichia coli	Fever, back pain	Antibiotics	Prompt treatment of cystitis
Leptospirosis	Leptospira interrogans	Fever, jaundice	Doxycycline	Avoid contaminated water
Chlamydia	Chlamydia trachomatis	Often asymptomatic, PID	Azithromycin	Safe sex
Gonorrhea	Neisseria gonorrhoeae	Discharge, pain	Ceftriaxone	Safe sex
Syphilis	Treponema pallidum	Chancre, rash, complications	Penicillin	Safe sex
Bacterial vaginosis	Gardnerella vaginalis	Discharge, odor	Metronidazole	Hygiene
Candidiasis	Candida albicans	Itching, discharge	Fluconazole	Hygiene
Trichomoniasis	Trichomonas vaginalis	Frothy discharge	Metronidazole	Safe sex
Genital herpes	HSV-2	Vesicles, ulcers	Acyclovir	Safe sex
Genital warts	HPV	Warts	Removal	HPV vaccine
AIDS	HIV	Immunodeficiency	Antiretrovirals	Safe sex, screening