Chapter 24
Infectious Diseases Affecting Urinary and Reproductive Systems
• Sexually transmitted diseases (STDs) remain a health problem in the United
States and around the world, the seriousness of which is underscored by a number
of infections.
24.1 The Structure of the Female and Male Urinary System
• The urinary system removes waste products from the blood and helps maintain
homeostasis
• The urinary system harbors an indigenous microbiota
• The distal region of the urethra is usually colonized by a variety of
bacterial species
• Many of the defense mechanisms operating in the male urethra are similar
to those of the female urethra
24.2 Urinary Tract Infections Caused by Bacteria
• Infections of the urinary tract are the second most common type of infection in the
body
• Occur primarily in the urethra and bladder
• 1/3 to 1/2 of humans suffer a UTI at some time in their lives
• Most urinary tract infections involve the urethra or bladder
• UTIs have similar signs and symptoms
• Urethritis
• Cystitis
• Prostatitis
• Pyelonephritis
• Leptospirosis is a zoonotic disease affecting the kidneys and other tissues
24.3 The Structure and Indigenous Microbiota of the Female and Male Reproductive
Systems
• The male and female reproductive systems consist of primary and accessory sex
organs
• Portions of the male and reproductive systems have a microbiota
24.4 Non-Sexually Transmitted Infections of the Reproductive System
• Common vaginal infections come from indigenous microbiota
• Changes in the microbiota affect the vaginal environment
• Bacterial vaginosis
• Vaginal candidiasis
24.5 Sexually Transmitted Diseases Caused by Bacteria
• STDs continue to be a major public health challenge in the United States
• STDs were commonly called venereal diseases (venerea = referring to
Venus, the Roman goddess of love)
• Chlamydial urethritis is the most frequently reported STD
• Can be asymptomatic
• Chlamydial urethritis (chlamydia) is caused by Chlamydia trachomatis
• Chlamydia is the most commonly reported notifiable disease in the United
States
• Chlamydia is one of several diseases known as a non-gonococcal urethritis
(NGU)
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85–90% of infected individuals are asymptomatic
C. trachomatis cannot make its own ATP and must rely on the host cell
for energy
• It has two phases: the infectious elementary body and the noninfectious
reticulate body
• Spreading to the fallopian tubes can cause salpingitis
• Left untreated, it can cause PID
• Males complain of painful urination and watery discharge
• It can cause infertility in males
• Chlamydia can also occur in the pharynx or anus
• Newborns can contract chlamydial ophthalmia during delivery
• Infection can be detected by a fluorescent antibody test or DNA analysis
• Species of Chlamydia are used to investigate the evolution of
pathogenicity
Gonorrhea Can Be an Infection in Any Sexually Active Person
• Gonorrhea is caused by Neisseria gonorrhoeae
• Gonorrhea can also affect the
• reproductive organs
• pharynx
• rectum
• eyes
• Infants can contract gonococcal ophthalmia while passing through the
birth canal
• In females it can spread to the fallopian tubes, causing
• pelvic inflammatory disease (PID)
• possible sterility
• ectopic pregnancy
• salpingitis
• Many affected females are asymptomatic
• Males experience
• tingling of the penis
• pain when urinating
• penile discharge
• swollen lymph nodes
• painful testicles
• It can cause infertility in males
Syphilis Is a Chronic, Infectious Disease
• Syphilis is one of the top five most reported microbial diseases in the
United States
• It is caused by Treponema palladium, a spirochete for which humans are
the only host
• Primary syphilis is characterized by a lesion (chancre) where the bacteria
entered the body
• Secondary syphilis involves
• fever
• skin rash
• swollen lymph nodes
• A chronic latent stage of 3–30 years follows in which relapses of
secondary syphilis occur
• Tertiary syphilis involves formation of gummas that can cause
• weakening and bursting of blood vessels
• degeneration of spinal cord tissue
• brain damage leading to personality and judgment changes and
insanity
• Congenital syphilis can occur in the fetus of a pregnant woman, leading to
• stillbirth
• birth defects like Hutchinson’s triad
• Other Sexually Transmitted Diseases Also Exist
• Chancroid Causes Painful Genital Ulcers
• Chancroid (soft chancre) is caused by Haemophilus ducreyi
• It is common in areas with low public health standards and tropical
climates
• A papule forms at the entry site that fills with pus and breaks down
• This leaves a painful, bleeding ulcer
• Lesions often form on the penis in men, labia or clitoris in females
• Ureaplasmal Urethritis Produces Mild Symptoms
• It is an NGU caused by Ureaplasma urealyticum (T-mycoplasma)
• Symptoms are similar to those of gonorrhea or chlamydia but are often
mild
• Infertility can occur in men, salpingitis in women
• U. urealyticum can colonize the placenta during pregnancy, causing
• miscarriage or
• premature birth
• Lymphogranuloma venerium (JGV) is caused by a different serotype of C.
trachomatis than chlamydia
• It is more common in men than women
• It is common in Southeast Asia and Central and South America
24.6 Sexually Transmitted Diseases Caused by Viruses and Parasites
• Some herpesviruses are associated with reproductive system infections
• The herpes simplex viruses cause benign infections
• Genital herpes
• Some papillomaviruses are associated with genital warts and cancer
• Genital warts (condylomata) are often transmitted through sexual contact
• Some strains of HPV are associated with cervical cancer
• They may be transmitted to newborns during delivery
• Trichomoniasis is the most common STD in young, sexually active
women
• It is caused by Trichomonas vaginalis, a protozoan parasite which
infects the urinary tract