About Urinary tract infection (UTI)
A urinary tract infection (UTI) is a bacterial infection that affects
any part of the urinary tract. The most common type of UTI is acute
cystitis often referred to as a bladder infection. An infection of the
upper urinary tract or kidney is known as pyelonephritis and is
potentially more serious.
Urinary tract infection: Incidence, age and sex
Bladder infections are most common in young women with about 10% of
women getting an infection yearly and 60% having an infection at some
point in their life. Nearly 1 in 3 women will have had at least 1
episode of urinary tract infections requiring antimicrobial therapy by
the age of 24 years. The risk of urinary tract infection increases with
increasing duration of catheterization. In non-institutionalized elderly
populations, urinary tract infections are the second most common form
of infection, accounting for nearly 25% of all infections.
Signs and symptoms of urinary tract infection: Diagnosis
The most common symptoms of a bladder infection are burning with
urination (dysuria), frequency of urination and an urge to urinate. The
symptoms of urinary tract infections may vary with age and the part of
the urinary system that was affected. In young children, urinary tract
infection symptoms may include diarrhea, loss of appetite, nausea and
vomiting, fever and excessive crying. Older may experience abdominal
pain or incontinence. Lower urinary tract infections in adults may
manifest with symptoms including haematuria (blood in the urine),
inability to urinate despite the urge and malaise. Other signs of
urinary tract infections include foul smelling urine and urine that
Infection of the kidneys (acute pyelonephritis) typically causes more
serious symptoms such as chills, nausea, vomiting and high fever. In
newborns the condition may cause jaundice and hypothermia, in the
elderly, symptoms of urinary tract infections may even include lethargy
and a change in the mental status.
Confirmation via urine microscopy looking for the presence of red
blood cells, white blood cells and bacteria is useful. Urine culture is
useful to guide the choice of antibiotics.
Causes and prevention of urinary tract infection
When bacteria gets into the bladder or kidney and multiply in the
urine, they may cause an UTI. The main etiologic agent is Escherichia
Urinary tract infection: Complications
UTIs may develop into very serious, life-threatening kidney
infections (pyelonephritis) that may permanently scar or damage the
kidneys leading to renal hypertension and eventual kidney failure. The
infection may also spread into the bloodstream and then elsewhere in the
In pregnant women, UTI may lead to the baby being born premature and also developing sepsis.
Urinary tract infection: Treatment
Uncomplicated UTIs can be treated with oral antibiotics such as
trimethoprim, cephalosporins, nitrofurantoin, or a fluoroquinolone such
as ciprofloxacin. About 50% of people will recover without treatment
within a few days or weeks.
Pyelonephritis is treated more aggressively than a simple bladder
infection using either a longer course of oral antibiotics or
intravenous antibiotics. Regimens vary, and include SMX/TMP ,
fluorquinolones and aminoglycosides (such as gentamicin) used in
combination with a beta-lactam, such as ampicillin or ceftriaxone. These
are continued for 48 hours after fever subsides.
If there is a poor response to IV antibiotics (marked by persistent
fever, worsening renal function), then imaging is indicated to rule out
formation of an abscess either within or around the kidney, or the
presence of an obstructing lesion such as a stone or a tumour.