Although the organisms causing urinary tract infections and sexually transmitted diseases target the same general area of the body, even causing some of the same symptoms, the specific organs they infect are very different as are the organisms themselves, and their mechanisms of transmission, pathogenesis, and epidemiology.
Urinary tract infections (UTI's) usually refer to infections of the bladder (cystitis) or the kidney (pyelonephritis) and are usually caused by the common intestinal bacterium, E. coli. Proteus, Klebsiella and one species of Staphylococcus can also cause UTI's. They are most common in young, sexually active women (though NOT sexually transmitted) and old men. Children and young men rarely get these infections. Prostatitis is also most often caused by E. coli and is often associated with a UTI. All these diseases present with dysuria and/or urinary frequency with varying degrees of fever and other constitutional symptoms.
Sexually transmitted diseases (STD's) are of three kinds; drips, bumps, and potholes. The ÒdripsÓ are the urithritides, or infections of the urethra. These are caused virtually 100% of the time by Neisseria gonorrhea or Chlamydia trachomatis or the two together and are only transmitted by sexual contact. Ureaplasm urealyticum and a very few other uncommon bacteria can also cause urethritis. Women are often asymptomatic although may have some dysuria. Men suffer from dysuria and a discharge of mucous or pus or a combination of the two. Although not agreed upon by all physicians, there are some indications that gonorrhea produces a more purulent discharge than does Chlamydia.
In women there can also be trichomoniasis and yeast infections which cause various and sundry discharges. Trichomoniasis is sexually transmitted although yeast infections are thought not to be.
The ÒbumpsÓ are either genital warts, caused most commonly by papilloma virus or, rarely, a pox virus called molluscum contagiosum, or they are swollen inguinal lymph nodes. The swollen lymph nodes occur with many of the genital ulcer diseases (the ÒpotholesÓ).
Genital ulcer disease has a variety of causes. The most common is Herpes simplex virus (HHV2), but syphilis (Treponema pallidum) and chancroid (Haemophilus ducreyii) are also genital ulcer diseases. Two rarer ones are lymphogranuloma venereum and Donovanosis or granuloma inguinale.
You can read about all of these diseases in Chapter 9 of Infectious Diseases in 30 Days by Frederick S. Southwick or the appropriate chapters in your big Microbiology textbook. All the organisms and the diseases they cause are described in the BUGS database. The following questions and cases will test your knowledge and help you understand these diseases.
Question 1 - Single Best Answer
Which of the following diseases have symptoms that can mimic the symptoms of cystitis?
A) syphilis
B) gonorrhea
C) chancroid
D) papilloma virus
Question 2 - Single Best Answer
In what group of individuals are UTI's (cystitis and pyelonephritis) common?
A) young children and old men and women
B) sexually active young men and women
C) sexually active young women and old men
D) young children and catheterized patients
Question 3 - Single Best Answer
Why are women more susceptible to UTI's than men?
A) they are more sexually active
B) they have shorter urethras
C) the lactobacillus in their vaginas makes them more susceptible
Question 4 - Single Best Answer
What is the major host defense against both urinary tract infections and some of the STD's?
A) IgG
B) cell mediated immunity
C) IgA
D) mucosal surface washing
Question 5 - Single Best Answer
What bacterial virulence factor is present on all organisms causing UTI's and most causing STD's?
A) capsule
B) fimbriae
C) Fc receptors
D) endotoxin
Question 6 - Single Best Answer
What distinguishes cystitis from pyelonephritis?
A) fever
B) chills
C) costovertebral angle pain
D) nausea
E) all of the above
F) none of the above, they can't be distinguished by symptoms alone
Question 7 - Single Best Answer
What is one virulence MECHANISM shared by almost all organisms causing STD's?
A) intracellular growth
B) extracellular growth
C) breakdown of IgA
D) production of inapparent infections
E) increase sexual activity