Symptoms and diagnosis of Urinary tract infection (UTI)

Symptoms of UTI

The most characteristic symptoms of UTI are:

#Frequency of micturition by day and night
#Pain while voiding urine (dysuria)
#Suprapubic pain and tenderness
#Haematuria or blood in the urine
#Abnormal or foul smell in the urine.

These above mentioned symptoms points to bladder and urethral inflammation, commonly known as 'cystitis', and suggest infection in the lower urinary tract. Loin pain and tenderness, associated with fever and other systemic symptoms, imply extension of the infection to the pelvis and kidney. This condition is known as pyelitis or pyelonephritis. However, localization of the site of infection is often not reliable only on the basis of symptoms.


UTI may also be present with negligible or no complaints or may present with atypical symptoms like abdominal pain, fever or blood in the urine with no complaints of frequency or dysuria. In small kids, who cannot express dysuria, symptoms are mostly 'atypical'. There is always a possibility of UTI in the fretful, febrile sick child who fails to thrive.

Diagnosis of Urinary Tract Infections (UTI)

The diagnostic criteria of UTI are based on quantitative culture of a clean catch midstream specimen of urine and the presence or absence of pyuria. A diagnosis based on inflexible observance to a bacterial count of at least 105 organisms per milliliter of urine in symptomatic women is not always correct. Diagnosis of 'low count bacteriuria' i.e. 102 organisms requiress additionally the presence of pyuria for diagnosing UTI. Dipstick tests is used to sense nitrites in urine. Most Gram- negative organisms reduce nitrates to nitrites and create a red color in the reagent square. False negative results are common. Dipsticks that detect significant pyuria bank on the discharge of esterases from leucocytes. Dipstick tests positive for both nitrite and leucocyte esterase are highly suggestive of acute infection (sensitivity of 75% and specificity of 82%).



Special investigations in the diagnosis of UTI

Uncomplicated UTI usually does not require radiological evaluation unless it is recurrent or affecting males and children or there are unusually severe symptoms. Those with predisposing conditions such as diabetes mellitus or immunocompromised states may be advised for early imaging. If pyonephrosis is suspected clinically, early imaging and surgical drainage is necessary. Intravenous urography and ultrasound are used in the evaluation of these patients, allowing the detection of stones, obstruction, and incomplete emptying, but these tests are done only in the adults. CT is a more sensitive investigation for diagnosis and follow-up of complicated renal tract infection. In Contrast-enhanced CT different phases of excretion can be studied and this can define the extent of disease and identify major complications or obstruction. Nuclear medicine has a restricted role in the assessment of UTI in adults. Its main function is in the evaluation of renal function, usually prior to surgery. MRI is predominantly of use in those with iodinated contrast allergies, offering an ionizing radiation-free substitute in the diagnosis of both medical and surgical disease conditions of the kidney.

How UTI Occurs?
Complicated, Uncomplicated, recurrent and relapsing UTI
Symptoms and diagnosis of UTI
Treatment of UTI
Special types of UTI