Jane David is a 35-year-old female who presented with the complaint of feeling unwell for 2 to 3 weeks. On questioning, it appeared that her symptoms are vague. She complains of loss of energy and feeling generally unwell. On closer questioning, it was apparent that she has had some dysuria and frequency of micturition. She also states that she is now passing much less urine than her usual. It was also revealed that she is slightly nauseous and has no appetite. Despite these, she is feeling heavy. Student nurses suggested she has probably urinary tract infection (UTI).Symptomatic acute bacterial urinary tract infections (UTIs) are among the most common bacterial infections treated by health care professionals. Cystitis accounts for most of these, whereas more than 100,000 patients are admitted to a hospital annually for acute pyelonephritis treatment. Women have many more UTIs than men. Bacteria ascending from the colonized urethra enter the bladder and perhaps the kidneys. The short length of the female urethra allows easier access by bacteria to the bladder. Contributing to contamination, the warm moist vulva and rectum are both in close proximity. Similarly, sexual intercourse increases bladder inoculation. Infections result from the interaction between bacteria and host. Bacterial virulence factors are important, as they enhance colonization and invasion of the lower and upper urinary tract. The principal virulence factor is increased adherence to either vaginal or uroepithelial cells. The bacterial species most frequently recovered from infected urine culture is Escherichia coli.
Bacterial cystitis almost always results from the entry of bacteria colonizing the anterior urethra and periurethral skin into the bladder. Hematogenous or lymphatic spread from sites of infection elsewhere is very unusual. The short female urethra is an insufficient anatomic barrier to the entry of urethral bacteria, which may be massaged easily into the bladder. This may explain the association of urinary tract infections and bacteriuria with sexual activity. Presumably, bacteria are massaged into the bladder during sexual intercourse. Once within the bladder, bacteria may ascend within the ureters, enhanced by vesicourethral reflux, into the renal pelvis and cause upper tract infection. The renal parenchyma also can be infected by blood-borne organisms, especially during staphylococcal bacteremia. Mycobacterium tuberculosis gains access to the kidney through this route and also perhaps by ascension.
Signs and Symptoms
There is a broad spectrum of symptoms in UTIs, ranging from patients who are completely asymptomatic to those with symptoms referable to the urethra, bladder, or both, and to those with the full-blown syndrome of acute pyelonephritis with fever and loin pain. Acute bacterial infection of the bladder is referred to as acute cystitis. Acute cystitis is characterized by inflammation limited to the superficial mucosal layer of the bladder. Patients with cystitis generally complain of dysuria, urgency, and frequency. Hematuria, low back pain, and lower abdominal pain also may be present. Fever and costovertebral-angle tenderness are both absent in most cases. Clinical signs and symptoms are notoriously inaccurate in localizing the site of infection, however, and up to 50% of women with symptoms and signs of cystitis on clinical examination are found to have silent renal infection.
The most frequent presenting complaints in otherwise healthy, immunocompetent nonpregnant women are dysuria, frequency, urgency, and incontinence. For a culture specimen to be informative, it must be accurately collected. A "clean catch" midstream voided urine specimen is usually sufficient. It is mandatory that a patient understands the reasons for and the steps associated with urine specimen collection, which are designed to prevent contamination by other bacteria from the vulva, vagina, and/or rectum. More than one bacterial species