Laboratory Aids in the Diagnosis and Treatment of Urinary Tract Infections
PYELONEPHRITIS and related infections of the urinary tract are among the most frequently undiagnosed and most difficult to manage of all infectious diseases. A few selected data will indicate the magnitude of this problem: (1) pyelonephritis is the commonest renal lesion found at autopsies, and has been reported in up to 20 per cent of consecutive necropsies;1,2 (2) the clinical diagnosis of urinary tract infection had been made in only 20 per cent of those patients who at necropsy were found to have active pyelonephritis, and the diagnosis is missed equally often whether massive or minimal lesions are present.2 This disparity between clinical diagnosis and autopsy findings indicates that overt clinical symptoms of pyelonephritis are frequently absent.
The natural course of pyelonephritis has been described as a series of separate episodes of infection. Now, evidence suggests that pyelonephritis is a disease continuum, and in many cases the episodes of acute infection are linked by an asymptomatic but active infection that is constantly taking its toll on renal function.3 The initial event in the relentless course of chronic pyelonephritis may occur during childhood. Macaulay and Sutton,4 as well as others,5,6 reported that chronic infection developed in from 30 to 60 per cent of children who had urinary tract infection in childhood. The recent studies by Kass7 on the occurrence of true bacilluria (100,000 or more organisms per milliliter of urine) in asymptomatic patients have shown a high incidence of asymptomatic pyelonephritis in the general population.
It becomes readily apparent that one . . .