Biology of Disease

INFECTIONS OF THE UROGENITAL SYSTEM

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Urethritis

Kidney

Ureter

Bladder

Urethra

Cystitis

Prostatitis

Pyelonephritis

Ascending infection from

fecal microorganisms

Infection from

blood-borne

parasites

Figure 3.16 Some infections associated with the urogenital system. See text for discussions.

called cystitis. Escherichia coli is the most common agent causing up to 80% of
the relatively uncomplicated UTIs, like cystitis. Women are more prone than
males to cystitis because of their relatively short urethra and the hormonal
changes associated with the menstrual cycle (Chapter 7). Cystitis is readily
treated by increasing the uptake of fluids, particularly of acid drinks like
cranberry juice, which causes increased flushing of the bladder, and by the
use of antibiotics. Unfortunately, reinfections are frequent.

Pseudomonas aeruginosa (Figure 2.1) has been known to cause UTIs following
hospitalization. Similarly, infections by Enterococcus faecalis and Klebsiella
pneumoniae have followed organ transplants (Chapter 6). Unfortunately,
these organisms often show multidrug resistance against antibiotics (Box 3.4).
Thrush in the bladder, caused by the yeast Candida albicans can also occur
following antibiotic treatment.

There has been a large increase in the incidence of sexually transmitted
diseases (STDs) in the UK in recent years. Sexually transmitted diseases can
affect the urinary system and the genital tract and are caused by a wide range
of different pathogens. Human papilloma virus (HPV ) can cause anogenital
warts (condyloma acuminata). Strains 16 and 18 of HPV cause lesions in the
cervix that are involved in the development of cervical carcinoma. Infection
withHerpes simplex virus (HHV-2) can lead to genital herpes with painful
ulcers and vesicular lesions of the genital mucous membrane. Infection with
human immunodeficiency virus (Box 3.1) leads to acquired immunodeficiency
syndrome (AIDS).