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 body and regulation of water and electrolyte balance. It consists of:

• Kidneys: Filter blood to 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: Includes testes, epididymis, vas deferens, seminal vesicles, prostate gland, and penis.

• Female: Includes ovaries, fallopian tubes, uterus, cervix, and vagina.

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 a kidney infection, often resulting from untreated cystitis.

• Organism: Usually Escherichia coli.

• Signs/Symptoms: Fever, back/flank pain, nausea, vomiting.

• Treatment: Intravenous antibiotics.

Leptospirosis

Leptospirosis is a zoonotic disease caused by Leptospira interrogans.

• Transmission: Contact with water contaminated by animal urine.

• Signs/Symptoms: Fever, headache, muscle pain; can progress to kidney or liver failure.

• Treatment: Doxycycline or penicillin.

Reproductive System Diseases

Chlamydia

Chlamydia is caused by Chlamydia trachomatis.

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

• Complications: Can cause trachoma (eye infection) and pelvic inflammatory disease (PID).

• Treatment: Azithromycin or doxycycline.

Gonorrhea

Gonorrhea is caused by Neisseria gonorrhoeae.

• Signs/Symptoms: Purulent discharge, dysuria.

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

• Treatment: Ceftriaxone and azithromycin.

Pelvic Inflammatory Disease (PID)

PID is an infection of the female reproductive organs, often caused by Chlamydia trachomatis or Neisseria gonorrhoeae.

• Complications:

  • Salpingitis: Inflammation of fallopian tubes.

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

• Signs/Symptoms: Pelvic pain, fever, abnormal discharge.

• Treatment: Broad-spectrum antibiotics.

Syphilis

Syphilis is caused by Treponema pallidum. It progresses through several 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 including:

  • Gummatous syphilis: Soft, tumor-like growths (gummas).

  • Cardiovascular syphilis: Affects heart and blood vessels.

  • Ocular syphilis: Eye involvement.

  • Neurosyphilis: Nervous system damage.

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

• Treatment: Penicillin G.

Bacterial Vaginosis

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

• Signs/Symptoms: Thin, grayish discharge, fishy odor.

• Treatment: Metronidazole.

Candidiasis

Candidiasis is a fungal infection 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: Acyclovir, valacyclovir (reduce symptoms, not cure).

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 by cryotherapy, topical agents.

• Prevention: HPV vaccine.

AIDS (Acquired Immunodeficiency Syndrome)

AIDS is caused by Human Immunodeficiency Virus (HIV).

• Transmission: Sexual contact, blood, mother-to-child.

• Stages of HIV infection:

  1. Acute infection: Flu-like symptoms, high viral load.

  2. Clinical latency: Asymptomatic or mild symptoms; virus replicates slowly.

  3. AIDS: Severe immunodeficiency; opportunistic infections, cancers. Diagnosed when CD4+ T cell count < 200 cells/µL.

• Prevention: Safe sex, needle exchange, antiretroviral therapy for pregnant women.

Summary Table: Major Genitourinary Diseases

Disease	Organism	Signs/Symptoms	Treatment	Prevention
Cystitis	E. coli, S. saprophyticus	Dysuria, urgency	Antibiotics	Hygiene
Pyelonephritis	E. coli	Fever, back pain	IV antibiotics	Prompt UTI treatment
Leptospirosis	Leptospira interrogans	Fever, muscle pain	Doxycycline	Avoid contaminated water
Chlamydia	C. trachomatis	Often asymptomatic	Azithromycin	Safe sex
Gonorrhea	N. gonorrhoeae	Discharge, dysuria	Ceftriaxone	Safe sex
Syphilis	T. pallidum	Chancre, rash, gummas	Penicillin G	Safe sex
Bacterial vaginosis	G. vaginalis	Discharge, odor	Metronidazole	Hygiene
Candidiasis	C. albicans	Itching, discharge	Fluconazole	Hygiene
Trichomoniasis	T. vaginalis	Frothy discharge	Metronidazole	Safe sex
Genital herpes	HSV-2	Vesicles, ulcers	Acyclovir	Safe sex
Genital warts	HPV	Warts	Cryotherapy	HPV vaccine
AIDS	HIV	Immunodeficiency	ART	Safe sex, needle exchange

Example: Chlamydia trachomatis can cause both genital infections and trachoma, a leading cause of blindness worldwide.

Additional info: PID is a major cause of infertility in women due to scarring of the fallopian tubes. HIV/AIDS is diagnosed as AIDS when CD4+ T cell count drops below 200 cells/µL.