Urinary tract infection diagnosis

Tambyah, P.A., 2004. Catheter-associated urinary tract infections diagnosis and prophylaxis. International Journal of Antimicrobial Agents 24, 44 8. 

Fig. 24.23a,b. Focal pseudotumoral pyelonephritis in a 15-month-old girl presenting with fever. Homogeneous small hyperechoic area on US (a) and hypoattenuating area on enhanced CT scan (b) without mass effect. No biopsy performed. Urinary tract infection diagnosis was based on bac-teriuria (E. coli) and disappearance ofthe lesion on US under antibiotic therapy... 

Johnson JR, Stamm WE. Urinary tract infection in women diagnosis and treatment. Ann Intern Med 1989 11 906-917. 

Delirium is a clinical diagnosis, based on the recent and abrupt appearance of clouded consciousness, with disorientation in time, and then in place and person. The patient can appear perplexed at first, gradually becoming frankly paranoid and aggressive, often with visual hallucinations. In elderly patients without clear localizing signs, acute toxic confusion is most often related to urinary tract infection. 

The infecting organism is not identified by the clinical diagnosis, e.g. in urinary tract infection or abdominal surgical wound infection. 

Clinical evidence suggestive of analgesic nephropathy includes nocturia, renal insufficiency with severe acidosis, persistent urinary tract infection with colic, hematuria, and hypertension (40,41). Nocturia resulting from failure to concentrate urine is usually the earliest functional defect, but like the other symptoms it is non-specific, rendering the diagnosis of analgesic nephropathy difficult. A CT scan showing bilateral small kidneys with bumpy contours, and papillary calcification is accepted to be of sufficient specificity (38,39). 

Diabetic nephropathy is a clinical diagnosis based on the finding of proteinuria in a patient with diabetes and in whom there is no evidence of urinary tract infection. Overt nephropathy is characterized by protein excretion greater than 0.5g/day. This is equivalent to albumin excretion of around 300mg/day. It is preferable to assess proteinuria as albuminuria because it is a more sensitive marker for CKD... 

A 5-year-old Egyptian boy receives a sulfonamide antibiotic as prophylaxis for recurrent urinary tract infections. Although he was previously healthy and well-nourished, he becomes progressively ill and presents to your office with pallor and irritability. A blood count shows that he is severely anemic with jaundice due to hemolysis of red blood cells. Which of the following would be the simplest test for diagnosis ... 

Urodynamic studies are the gold standard for diagnosis. Also urinalysis and urine culture should be negative (rule out urinary tract infection as cause of frequency). 

Pappas PG. Laboratory in the diagnosis and management of urinary tract infections. Med Clin North Am 1991 75 313-325. 

Lipsky GA. Urinary tract infections in men Epidemiology, pathophysiology, diagnosis, and treatment. Ann Intern Med 1989 110 138-150. 

Coal Tar Products. Elevated red and white cell counts in urine were noted in 6-8% (29-34 of 452) of the employees examined in an industrial health survey in nine coal tar plants in which coal tar creosote and coal tar were the main treatments used (TOMA 1981). Some of these cell count elevations were attributed to urinary tract infections resulting from inadequate personal hygiene, and not to industrial exposure to toxic chemicals. However, some of the workers with elevated red and white cell counts in urine had cellular and granular casts and traces of protein, suggesting abnormal renal function. These individuals were referred to their physicians for diagnosis. No determination of exposure was made at the nine coal tar plants (TOMA 1981). Moreover, no clear relationship could be established because exposure routes in addition to inhalation (e.g., oral and dermal) were likely. Also, the ability to relate renal effects to coal tar creosote and coal tar exposure was further confounded by the possibility that the subjects were also exposed to other chemicals and cigarette smoke. Additional limitations of the study included seasonal and geographical variation in plant locations, past employment history, voluntary participation in the study that could have biased it in favor of healthy workers, lack of statistical analyses, lack of adequate controls, and use of only current employees. 

Patients usually do not have abnormalities in the hematocrit, hemoglobin, or platelet levels. The peripheral white blood cell count may range between 5,000 and 22,000 cells per microliter, but it is usually only mildly elevated. Differential blood cell counts are usually normal, although patients may have a lymphocytosis late in the disease.13 67 Patients may have microscopic pyuria, which may lead to the erroneous diagnosis of a urinary tract infection.13,68 Mild elevations in lactic dehydrogenase, serum transaminases, and alkaline phosphatase are commonly seen. Some patients may experience rhabdomyolysis associated with elevations in the serum creatine kinase and urinary myoglobin lev-... 

A 24-year-old woman with spina bifida presented to the emergency department feeling unwell. Her ankles were swollen and she was noted to have recently had a urinary tract infection. She was treated with antibiotics and discharged home. A week later she was admitted to hospital with very swollen lower limbs, high blood pressure and raised central venous pressure. A diagnosis of hypertensive congestive cardiac failure was made, delayed a week because of an incomplete initial assessment in the emergency department. 

Pulmonary toxicity is a commonly encountered side effect of nitrofurantoin thought to occur in 1% of the cases (3). It is typically used prophylactically to prevent urinary tract infections and understandably, most patients are older female patients (17). This information may not be systematically volunteered by the patients. Hence, a high degree of suspicion is required to make the diagnosis. Two temporal patterns of pulmonary toxicity have been described. 

Dacher JN, Mandell J, Lebowitz RL (1992) Urinary tract infection in neonates in spite of prenatal diagnosis of hydronephrosis. Pediatr Radiol 22 401-405 Dacher JN, Pfister C, Monroe M, Eurin D, Le Dosseur P (1996) Power Doppler sonographic pattern of acute pyelonephritis in children. AJR 166 1451-1455 Dacher JN, Pfister C, Thoumas D et al (1999) Shortcomings of diuresis scintigraphy in evaluating urinary obstruction comparison with pressure flow studies. Pediatr Radiol 29 742-747... 

Indications for DIG (Mandell et al. 1997a,b) include female infants (<1 year of age) with a urinary tract infection (UTI) and a normal ultrasound or with a prenatal ultrasound diagnosis of hydronephrosis who postnatally are either normal or who have mild dilatation, and boys (<3 years of age) who require follow-up cystography. 

Fig.1.3.3. IRC recurrent urinary tract infection in a 4-year-old girl. Reflux into right kidney is noted on this indirect radionuclide cystogram despite the fact that there was no micturition. This suggests the diagnosis of an unstable bladder that was confirmed on further investigation...

Fig. 1.3.11. Tc-99m DMSA scan on the left in a girl with a urinary tract infection. There is a defect in the acute phase in the left kidney. This 2-year-old girl was severely ill with systemic illness and was found to have a urinary tract infection the US was normal. The Tc-99m DMSA scan on the right was undertaken 1 week after admission with the diagnosis of urinary tract infection. There are multiple defects in the left kidney that contributed 39% to overall function...

Nowadays, since the widespread use of obstetrical US, most cases of UPJ obstruction are detected in utero or in the direct neonatal period in asymptomatic patients. Rarely, the condition is revealed after the palpation of an abdominal mass, hematuria or urinary tract infection. Interestingly, despite antenatal diagnosis, cases of UPJ obstruction are still detected later in childhood. In older children, symptoms leading to the diagnosis include, among others, hematuria following an abdominal trauma, nausea, failure to thrive, and flank pain (Cendron 1994). 

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