EDITOR'S COLUMN I

Urinary tract infections in infancy

THE NOVEL OBSERVATION on urinary tract infections in infants reported by Randolph and associates in this issue deserve comment. They are remarkable people who demonstrate once again that careful prospective studies c o n d u c t e d in a practice s e t t i n g can be rewarding both personally and to the general medical community. My remarks will be directed toward a critical analysis of their report, not to nit-pick, but hopefully to aid interpretation of their findings. The authors base their findings on three consecutive specimens of urine containing 100,000 or more bacteria per milliliter; the urine is collected by means of a strapon bag device. Despite claims for reliability of this procedure, the definitive test currently is with urine obtained by suprapuhic bladder puncture. It has been repeatedly shown that collection of urine for culture by plastic bags is unreliable except as a screening procedure. For example, Davies and associates 1 report the prevalence of bacteriuria in preschool girls to be 0.8% when confirmed by bladder puncture. They reported that voided specimens were frequently contaminated, often persistently in the first year of life. Out of 513 children under 12 months of age, 165 (33%) required repeat tests, 78 (15%) needed a third or subsequent test in the hospital and 32 (6.4%) required a suprapubic aspiration to exclude tube bacteriuria. One wonders whether Randolph and his group really have Convincing evidence that the U-Bag circumvents this difficulty. Results of follow-up of cases over a 6-year period are p e r h a p s the m o s t i n t e r e s t i n g f e a t u r e of this report. Recurrent bacteriuria (as defined by the authors) was c o m m o n , but c e a s e d after t h e third y e a r of life. I assume strap-on devices were no longer used by then. The six cases initially found to have reflux were shown to have normal voiding cystourethrograms at 6 years of age. It is expected that low grades of reflux will spontaneously disappear, whereas the renal scars they produced tend to remain. 2 We must be careful about calling these residual lesions "chronic pyelonephritis," This From the Department of Medicine, University of Wisconsin School of Medicine, and the Veterans Administration Hospital.

term implies either continuation of a low-grade infectious process or residual scars of old infection. No term in m e d i c i n e is m o r e s u b j e c t to c o n t r o v e r s y t h a n " p y e l o n e p h r i t i s . " R a n d o l p h and associates d e s c r i b e three infants with renal involvement characterized by white blood cell casts a n d localized cortical thinning and c l u b b i n g of t h e c o r r e s p o n d i n g calyx. All of t h e s e children had vesicoureteral reflux. There is good evidence from the work of Hodson and Wilson 3 and others that reflux by itself may lead to renal scars in childhood. I believe, therefore, that for the time being our terminology should be more descriptive than diagnostic, e.g., recurrent urinary tract infections (symptomatic or not) associated with reflux (or not) with development of cortical scars is more meaningful to me than use of the term pyelonephritis. See related article, p. 342. Despite these reservations and comments, it is clear that Randolph and his co-workers have made a significant contribution to this field. I am particularly impressed by the early detection of urologic abnormalities and the potential for preventing further infections. Diagnosis of urinary tract infection in young children is a very serious decision. It implies that urologic investigation be begun and therapy and close follow-up are needed. These are not without hazard and must be emotionally traumatic both to the parents and the patient. For this reason, it is essential to be absolutely certain one is dealing with true infection, particularly in the relatively asymptomatic child. Thus far, suprapubic puncture appears to be essential for accurate diagnosis of infection during infancy. There is a very real need for d e v e l o p m e n t of n e w n o n i n v a s i v e diagnostic procedures. W e have recently found that use of the nitrite test performed on three first morning specimens in adult f e m a l e s will d e t e c t a l m o s t 90% of true b a c teriurics. 4 It may not be suitable, however, for infants, since overnight culture of urine in the bladder is required for bacteria to reduce dietary nitrate to nitrite. Nevertheless, more work needs to be clone on tests of

Vol. 86, No. 3, pp. 483-484

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this type if we are to detect cases early with m i n i m u m effort and trauma. Calvin M. Kunin, M.D. Veterans Administration Hospital 2500 Overlook Terrace Madison, Wis. 53705 REFERENCES 1. Davies JM, Littlewood JM, Gibson GL, et al: PrevalenCe of bacteriuria in infants and preschool children, Lancet 2:7, 1974.

The Journal of Pediatrics March 1975

2.

3. 4.

RoUeston GL, Shannon FT, and Utley WLF: Relationship of infantile vesicoureteric reflux to renal damage, Br Med J 1:460, 1970. Hodson C J, and Wilson S: Natural history of chronic pyelonephritic scarring, Br Med J 2:191, 1965. Kunin CM and DeGroot J: Self-screening for significant bacteriuria: evaluation of dip-stick cultures and the nitrite test, (in press).

Editorial: Urinary tract infections in infancy.

EDITOR'S COLUMN I Urinary tract infections in infancy THE NOVEL OBSERVATION on urinary tract infections in infants reported by Randolph and associat...
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