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REVISTA ROMNDE PEDIATRIE VOLUMUL LX, NR. 4, AN 2011348

Adresa de coresponden:Ddr. Delia Andreia Bizim, Spitalul Clinic de Urgen pentru Copii Sf. Maria, Str. V. Lupu Nr. 62, Iaie-mail: [email protected]

RATA INFECIILOR URINARE LA COPIIICU HIDRONEFROZ CONGENITAL

DEPISTAI ANTENATALDelia Andreia Bizim1,2, Mihaela Munteanu2, Radu V. Russu2,

Ovidiu Brumariu2, Ingrith C. Miron2

1Doctorand al Universitii de Medicini Farmacie Gr.T. Popa,

Facultatea de Medicin, Iai2Clinica a IV-a Pediatrie, Spitalul Clinic de Urgene pentru Copii Sf. Maria, Iai

REZUMAT

Nou-nscuii depistai antenatal cu hidronefroz sunt supui unui risc de 12 ori mai mare de a dezvolta opielonefrit acut. n prezenta lucrare am evaluat frecvena infeciilor urinare pe un lot de 87 de pacieni cuhidronefroz congenital depistat antenatal (raport B:F = 2,95:1). Durata medie de urmrire a fost de 20,22luni. 49,42% dintre copii au prezentat infecii urinare, rata recidivelor( 2 episoade infecioase) fiind de 53,8%.Funcie de gradul hidronefrozei, frecvena infeciilor urinare a fost ntre 37,5-41,37% n cazul HN grad I-II i

ntre 57-71% n cazul HN grad III-V (p = 0,0402, CI 95%, HN gr. I-II comparativ cu HN gr. III-V). Am gsit ocorelaie pozitiv, dar slab ntre gradul HN i numrul de episoade infecioase (rS = 0,224, p = 0,036, CI95%) semnificativ statistic. 60,52% dintre pacienii cu istoric de ITU au prezentat infecii urinare suburoprofilaxie. Cefaclor a fost cel mai utilizat antibiotic. n etiologia infeciilor urinare E. coli a fost implicat n36,35% dintre cazuri, iar Klebsiella pn. n 25%. Avnd n vedere frecvena crescut a infeciilor urinare n acestlot, este necesar o urmrire mai ndelungat a acestor copii pentru depistarea precoce a afectrii renale.

Cuvinte cheie: hidronefroz congenital, infecie urinar, uroprofilaxie,diagnostic antenatal, hidronefroz antenatal, infecii urinare recidivante

STUDII CAZUISTICE

6

INTRODUCERE

Infeciile urinare sunt una dintre cele mai frec-vente afeciuni ntlnite n copilrie, fiind pe loculal doilea dup infeciile respiratorii.

Studiile epidemiologice au estimat c pn la2% dintre biei i 8% dintre fete vor prezenta oinfecie urinar pn la vrsta de 7 ani. (1,2)

Incidena pielonefritei ca i cauz de insuficien

renal terminal se menine crescut ntre 31,4%-34,8% (3,4), majoritatea episoadelor infecioasefiind asociat malformaiilor reno-urinare ca refluxvezico-ureteral (RVU) sau uropatie obstructiv.

Rinichiul pediatric are susceptibilitatea cea maimare de a dezvolta cicatrice renale n timpul pielo-nefritei acute, iar consecinele pe termen lung sunthipertensiune arterial i insuficien renal pro-gresiv. Nou-nscuii cu hidronefroz (HN) de-

pistat antenatal sunt supui unui risc de 12 ori mai

mare de a dezvolta pielonefrit n primul an devia (5), iar depistarea lor precoce, precum i pre-venirea ITU pot micora sensibil numrul de copiicu insuficien renal cronici al celor dializai.

Scopul principal al acestei lucrri este deter-minarea frecvenei infeciilor urinare (ITU) la unlot de pacieni cu hidronefroz antenatal. Totodat,se va urmri etiologia infeciilor urinare, rata recu-renei ITU i utilitatea uroprofilaxiei.

MATERIAL I METOD

Studiul retrospectiv a fost efectuat pe o duratde 10 ani (1 ianuarie 2001 31 decembrie 2010),

pe un lot de 146 de pacieni depistai antenatal cumalformaie reno-urinar. Aspectul ecografic de tiphidronefroz descris la ecografia antenatal a fost

prezent la 118 pacien i, confirmndu-se postnatal ncazul a 105 pacieni.

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REVISTA ROMNDE PEDIATRIE VOLUMUL LX, NR. 4, AN 2011 349

Dintre cei 105 pacieni am exclus 18 copii (1pacient a fost diagnosticat ulterior cu malformaieurogenital, i anume sinus urogenital, 4 copii da-torit datelor incomplete i 13 copii la care vrstalurii n eviden a fost peste 1 an). n final lotul destudiu a fost format din 87 de pacieni (fig. 1)

Am definit ca:1. infecie urinar clinic, prezena urmtoarelor:semne/simptome clinice specifice sau nespecifice

plus piurie/leucociturie (> 10 de leucocite/mm3)asociat bacteriuriei (> 105 UFC/ml) dintr-unspecimen de urin recoltat cu ajutorul punguelorcolectoare la copiii sub 2 ani i la cei fr controlmicional, iar la copiii peste 2 ani cu controlmicional din mijlocul jetului urinar

2. infecia urinar febril reprezint infecia urinarclinic ce asociaz febr peste 380 C documentat

la domiciliu sau n spital3. uroprofilaxia reprezint administrarea unui an-

tibiotic n doz redus (1/3-1/4 din doza tera-peutic) n scopul prevenirii recurenelor infec-ioase urinare cu o durat de minim 2 luni n

priz unic seara.Prin uropatie obstructiv nelegem o obstrucie

la orice nivel al tractului urinar, i anume la niveluljonciunii pieloureterale, ureterului, jonciunii ure-terovezicale, intravezical (de obicei, printr-un ute-rerocel) i subvezical (valv de uretr posterioar,atrezie uretral, stricturi uretrale).

Prelucrarea statistic a datelor a fost efectuatcu programul Portable Statistica8. Am aplicat testul

Spearman pentru stabilirea unor posibile corelaiintre variabile nonparametrice i testul T student

pentru compararea a 2 variabile independente. Unp

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n cazul HN grad III, 50-63,63% n cazul HN gradIV-V. O rat cuprins ntre 14,28-50% se nregis-treaz n cazul HN bilaterale grad I-II, de 33,3% ncazul HN bilaterale grad III i ntre 60-100% ncazul HN bilaterale grad IV-V (tab. I).

S-a utilizat testul Spearman pentru evaluarea

unei corelaii ntre prezena infeciilor urinare, res-pectiv numrul acestora, cu sexul pacientului i cugradul hidronefrozei. Am obinut o corelaie pozi-tiv, slab ntre gradul hidronefrozei i prezenainfeciilor (r

S= 0,22, p = 0,0345, CI 95%), respectiv

ntre gradul hidronefrozei i numrul de episoadeinfecioase (r

S= 0,22, p = 0,036, CI 95%), semnifi-

cative statistic.n cazul hidronefrozei grad III-V, avem un risc

mai mare pentru infecia urinar, ct i pentru nu-mrul de episoade comparativ cu HN gr. I-II (p =

0,040, respectiv p = 0,044, CI 95%).S-au nregistrat un numr de 99 de episoade in-fecioase, dintre care 85 de ITU pe durata urmririi,20/43 de pacieni (46,51%) prezentnd o singurITU. n 45,8% (39/85) au fost nsoite de febr >38C documentat la domiciliu sau n spital.

Comparativ cu bieii, fetele prezint un riscmai mare pentru infecii recidivante, n acest lotraportndu-se 0,9 episoade infecioase/pacient la

biei, comparativ cu 1,6 episoade infecioase/pa-cient la fete.

Rata recidivelor infecioase ( 2 ITU) a fost de53,48% (23/43 de pacieni). De menionat c 10pacieni (23,25%) au prezentat cel puin o infecieurinar naintea lurii n eviden (2 dintre acetiaavnd documentate cte 3 episoade).

Cincisprezece pacieni (34,88%) au suferit inter-venii chirurgicale, n dou cazuri fiind vorba dereimplantare ureterovezical pentru reflux vezico-ureteral sever (gradul V), restul cazurilorfiind deuropatie obstructiv. Doar 9 pacieni au prezentatinfecii urinare preoperator. Postoperator, cu excep-

ia unui pacient, toi au prezentat infecii urinare.Dintre cele 85 episoade de infecii urinare nre-gistrate, n 80 (94,11%) a fost implicat un singuragent etiologic, n 6 cazuri (7,05%) etiologia fiind

plurimicrobian.

Incidena E. coli a fost de 36,25%, urmat deKlebsiella pn. n 25% dintre cazuri. n ceea ce pri-vete ali ageni etiologici, incidena acestora a fostdup cum urmeaz: Enterococ 8,75%, Candida6,25%, Proteus 5%, Serratia, Morganella, Entero-

bacter i respectiv Pseudomonas aeruginosa cte

1,25%. Etiologia episodului infecios urinar nu afost precizat n 11,25% dintre cazuri, iar BGNneidentificat a fost prezent n 1,25% dintre cazuri.

n cazul infeciilor plurimicrobiene, n 83,3% (5dintre cele 6 cazuri) a fost implicat Pseudomonasaeruginosa. Nu am gsit o relaie ntre acest ger-mene i prezena unei intervenii chirurgicale (doarn 3/5 dintre cazuri).

n ceea ce privete uroprofilaxia, aceasta a fostiniiat la 38/43 dintre pacieni cu infecii urinare ila 27/44 pacieni fr istoric de ITU. Durata medie

a uroprofilaxiei la pacienii cu ITU a fost de 10,47luni. (min = 1,26 luni, max = 36 luni), comparativcu pacienii fr infecii urinare de doar 4,64 luni (p= 0,0035, CI 95%).

Dintre pacienii cu infecii urinare ce au urmaturoprofilaxie 23 (60,52%) au prezentat infecii uri-nare, 15 dintre ei cu cel puin un episod infecios. ncazul celor 5 pacieni ce au efectuat o profilaxieintermitent, incidena infeciilor urinare a fost de80% (4/5).

n realizarea uroprofilaxiei s-a utilizat o cefa-losporin n 51 dintre cazuri, i anume Cefaclor n50 de cazuri i Cefuroxim ntr-un caz.

DISCUII

Riscul de a prezenta o infecie urinar se core-leaz cu gradul hidronefrozei, astfel nct n cazulHN grad IV (conform criteriilor SFU Society ofFetal Urology), incidena ITU poate ajunge la 40%(6). n studiul de fa, rata infeciilor urinare a fost

de 71% (ntre 63,63-100%) n cazul HN grad. IV.Coehlo i colab. au estimat incidena cumulativa ITU a fi de 39%, 18% i 11% pn la vrsta de 3ani n cazul unei HN severe, moderate, respectivminor (7). Estrada a raportat o incident a infeciilor

Tabelul I. Rata infeciilor urinare funcie de gradul hidronefrozeii de afectarea uni/bilateral

HN unilateral HN bilateral

Grad

HN

Nr.

pacieni%

pacieni

Nr.

pacieniITU +

%

pacieniITU+

Nr.

pacieni%

pacient

Nr.

PacieniITU +

%

pacieniITU+

Nr.

pacieni%

pacieni

Nr.

PacieniITU +

%

pacieniITU+

1 24 27.58 9 37.5 20 83.3 7 35 4 16.6 2 502 29 33.3 12 41.37 22 75.86 11 50 7 24.1 1 14.28

3 13 14.94 8 61 10 76.92 7 70 3 23.07 1 33.3

4 14 16.09 10 71 11 78.57 7 63.63 3 21.4 3 100

5 7 8.04 4 57 2 28.57 1 50 5 71.42 3 60

Total 87 100 43 49.42 65 74.71 33 50.7 22 25.28 10 45.45

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urinare la pacienii cu HN gr. II de doar 1,3% (8), nschimb n aceast lucrare ea a fost de 41,27% (ntre14,28-50%, funcie de afectarea uni sau bilateral)

Conform Ghidului Asociaiei Americane deUrologie privind screeningul i managementulRVU primar la copii, revizuit n 2010, n seciunea

ce se refer la screeningul nou-nscuilor i su-garilor cu HN antenatal, se raporteaz o incidena ITU la acest grup de copii ntre 0,5-21,3% (9).Am gsit o rat de 49,42% a infeciilor urinare la

pacienii cu HN, totui doar 11,49% (10/87) avndistoric de ITU anterior lurii n eviden.

Rata recurenei ITU n primele 12 luni dup epi-sodul infecios urinar este de 10-30% (2,10), com-

parativ cu 53,48% n prezentul studiu. Frecvenacrescut a primoinfeciei, ct i a infeciilor urinarese poate explica printr-o complian sczut, muli

pacieni prezentndu-se n puseu acut sau acesteinfecii sunt depistate cu ocazia controalelor perio-dice.

Nu am evaluat substratul malformativ al HNcongenitale ca potenial factor de risc pentru infec-iile urinare.

Eficacitatea uroprofilaxiei n prevenirea ITU nua fost dovedit (11). Totui, ntr-un studiu randomi-zat ce a evaluat eficacitatea acesteia n reducerearecurenei infeciilor urinare la pacienii cu sau frRVU primar cu o prim infecie urinar, Craig icolab. au artat c administrarea unei doze mici deantibiotic (i anume, trimetoprim sulfametoxazol)

pe termen lung a fost asociat cu o scdere de 6% anumrului de infecii urinare la copiii succeptibili.(12)

Dintre cei 38 de pacieni cu istoric de infeciiurinare ce au primit antibioprofilaxie, 60,52% au

prezentat infecii urinare sub uroprofilaxie.Totui uroprofilaxia de rutin nu mai este reco-

mandat la nou-nscuii cu HN depistat antenatal.

Studii recente recomand utilizarea selectiv a uro-profilaxiei n urmtoarele cazuri: HN sever (defi-nit prin diametrul antero-posterior al pelvisuluirenal DAP a pelvisului renal > 15 mm), RVU

primar gr. III-IV, suspiciune de obstrucie (11,13).

Dintre cei 17 pacieni fr istoric de ITU i lacare nu s-a instituit uroprofilaxie, la 11 dintre eigradul hidronefrozei a fost gr. I i la un pacient HNgr. II. Aceast tendin de urmrire conservatoaren cazul HN de grad mic s-a nregistrat n ultimii 3ani (2008-2010).

n ceea ce privete etiologia infeciilor urinare,aceasta este diferit, funcie de prezena sau absenasubstratului malformativ i de tipul de malformaiereno-urinar.

n cazul pacienilor cu sau fr RVU primar,germenele implicat n peste 80-88% din cazuri esteE.coli (2,12,14), fiind urmat de Proteus n 4-5% dincazuri i Klebsiella n 3-4 % (12). Per total, inci-dena altor germeni gram negativi exceptnd E.coli(Klebsiella, Enterobacter, Proteus, Pseudomonas) n

etiologia infeciilor urinare este cuprins ntre 10-15%.Pseudomonas aeruginosa reprezint un patogenrar ntlnit, fiind implicat de obicei n etiologia in-feciilor recurente (datorit utilizrii antibioticelorcu spectru larg) sau n cazul prezenei unei patologiireno-urinare, incidena acestuia fiind de < 1% (12).

Arlen A.M. i colab. raporteaz o inciden a Ecoli. cuprins ntre 54-67%, iar a Klebsiellei. pn de6-17%. (15)

Incidena E. coli n etiologia infeciilor urinaredin acest studiu a fost de 36,25%, fiind urmat de

Klebsiella pn n 25% dintre cazuri, mult diferit decea raportat n literatur.

CONCLUZII

Lotul studiat reprezint o populaie selectiv,ntruct nu toi nou-nscuii depistai antenatal cumalformaie reno-urinar s-au prezentat pentru a filuai n evideni urmrii. Avnd n vedere frec-vena crescut a infeciilor urinare n acest lot, ct

i a recidivelor urinare ca i durat scurt de urm-rire sub 2 ani, este necesar o perioad mai lung deurmrire pentru depistarea precoce a afectrii re-nale i a consecinelor secundare (hipertensiuneaarteriali insuficiena renal).

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The frequency of urinary tract infections

in children with antenatal hydronephrosis

Delia Andreia Bizim1,2, Mihaela Munteanu2, Radu V. Russu2,

Ovidiu Brumariu2, Ingrith C. Miron2

1PhD student, Faculty of Medicine,

Gr.T. Popa University of Medicine and Pharmacy, Iasi24thPediatric Clinic, St. Mary Childrens Emergency Hospital, Iasi

ABSTRACT

Infants with antenatal hydronephrosis are at risk 12 times greater of developing acute pyelonephritis. Weevaluated the frequency of urinary tract infections (UTI) in a group of 87 patients with congenital hydronephrosis(HN) detected antenatally (ratio B: F = 2,95:1). The average follow-up was 20.22 months. 49.42% of childrenhad UTI, the recurrence rate ( 2 episodes) was 53.8%. Depending on the degree of hydronephrosis, urinaryinfection rate was between 37.5 to 41.37% for grade I-II HN and between 57-71% for grade III-V HN (p =0.0402, 95% CI grade I-II HN compared with grade III-V). We found a weak positive correlation between thedegree HN and the number of UTI (rs = 0.224, p = 0.036, 95% CI) significant statistic. 60.52% of patients with

a history of UTI had urinary infections on uroprophylaxis. Cefaclor was the most common used antibiotic. Ecoli was involved in 36.35% of UTI, and Klebsiella pn. 25%. Given the high frequency of urinary infections inthis group, it is neccesary a longer follow-up of these children for early detection of kidney damage.

Key words: congenital hydronephrosis, urinary tract infections, uroprophylaxis,antenatal diagnosis, UTI reccurence, antenatal hydronephrosis

INTRODUCTION

Urinary tract infections are one of the mostcommon diseases encountered in childhood, being

second after respiratory infections.Epidemiological studies have estimated that up

to 2% of boys and 8% of girls will experience aurinary tract infection before age 7. (1,2)

The incidence of pyelonephritis as a cause ofrenal failure remains increased between 31.4 to34.8% (3.4), most of UTI being associated withreno-urinary malformations as vesicoureteral reflux(VUR) and obstructive uropathy.

Pediatric kidney has the greatest susceptibility

to develop renal scarring during acute pyelonephri-tis, long-term consequences being hypertensionprogressive renal failure.

Infants with antenatal hydronephrosis (HN) are12 times more likely to develop pyelonephritis inthe first year of life (5), and their early detectionand prevention of UTI may reduce significantly thenumber of children with chronic renal failure andthose on dialysis.

The main purpose of this paper is to determinethe frequency of urinary tract infections (UTI) in a

group of patients with antenatal hydronephrosis.Also we studied the etiology of urinary infections,the UTI recurrence rate and the utility of uro-

prophylaxis.

MATERIAL AND METHODS

We conducted a retrospective study over aperiod of 10 years (January 1th, 2001- December

31th, 2010) on a group of 146 patients with antenatalrenal and urinary abnormalities. On antenatal ultra-sound hydronephrosis was present in 118 patients,

being confirmed postnatally on 105 patients.Of the 105 patients we excluded 18 children

(one patient was diagnosed later with urogenitalsinus, incomplete data on 4 children and the age >1 year at the date of presentation in 13 children).The final study group consisted of 87 patients(Figure 1).

We defined as:

1. clinical urinary tract infection as the presenceof: specific or nonspecific signs/symptoms plus

pyuria/leucocyturia (> 10 WBC/mm3) and bac-teriuria (> 105 CFU/ml) from a specimen ofurine collected by urinary bags on children un-der 2 years and those not toilet trained and intoilet trained children >2 years from the middleurinary stream.

2. febrile urinary tract infection was defined asclinical infection associated with fever >380Cdocumented at home or in hospital

3. uroprophylaxis: administration of a low dose ofantibiotic (1/3-1/4 of the therapeutic dose) to

prevent recurrence of UTI for a period of mini-mum 2 months in a single evening dose.

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Obstructive uropathy vas defined as an ob-struction at any level of the urinary tract, namelythe uretero-pelvic junction, the ureter, the uretero-vesical junction, the bladder (usually by autererocele) and the bladder outflow obstruction(posterior urethral valve, urethral atresia, urethral

stricture).Statistical analysis was performed by PortableStatistics 8 software. A Spearman test was appliedto determine possible correlations between non

parametrics variables and a T test to compare twoindependent variables. A value of p < 0.05 wasconsidered statistically significant (95% CI).

RESULTS

Of the 87 patients (F: B ratio = 1:2,95), 43 children

(49.42%) had urinary tract infections (UTI), thegender distribution being 54.54% (12/22) of girlsand of 47.69% (31/65) of boys.

Age of inclusion was

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infection (rs = 0.22, p = 0.0345, 95% CI) and between the degree of hydronephrosis and thenumber of UTI (rs = 0.22, p = 0.036, 95% CI).

Grade III-V hydronephrosis had a higher riskfor urinary infection and number of UTI comparedto grade I-II HN (p = 0.040, respectively p = 0.044,

95% CI).We found a number of 99 UTIs. During follow-

up we recorded 85 UTIs, 20/43 patients (46.51%)had a single UTI. Fever > 38 C documented athome or in hospital was present in 45.8% (39/85).

Compared with boys, girls were at greater riskfor recurrent UTI. Boys had 0.9 episodes/patientcompared to 1.6 episodes/patient in girls.

The recurrence rate ( 2 UTI) was 53.48%(23/43 patients). Ten patients (23.25%) had at leastone UTI before the inclusion in this study (two with3 UTIs each).

Fifthteen patients (34.88%) underwent surgery,two cases are for bladder reimplantation secondaryto severe vesicoureteral reflux (grade V), the restfor obstructive uropathy. Only 9 patients had

preoperative UTI. Except one patient, all hadurinary infections postoperatively.

Of the 85 UTIs recorded, in 80 (94.11%) wasinvolved a single pathogen. In 5 cases (7.05%) wefound two or more pathogens.

The incidence of E. coli was 36.25%, followed by Klebsiella pn. in 25% of cases. Enterococcuswas found in 8.75% cases, Candida in 6.25%,Proteus in 5%, Serratia, Morganella, Enterobacterand Pseudomonas aeruginosa in 1.25% each. Theetiology of UTI was not specified in 11.25% cases.Unidentified BGN was present in 1.25% cases.

Pseudomonas aeruginosa was involved in 83.3%(5 out of 6 cases) of plurimicrobial UTI. We did notfind a relationship between the germ and the surgery(only 3/5 cases).

Uroprophylaxis was initiated in 38/43 patientswith UTI and in 27/44 patients without UTI. Theaverage duration was 10.47 months for patients

Table I. Frequency of urinary tract infections based on the degree of hydronephrosis and on unilateral

versus bilateralhydronephrosis

Unilateral hydronephrosis Bilateral hydronephrosis

HN

Grade

No.

patients

Percent

patients

No.

patients

ITU +

Percent

patients

ITU+

No.

patients

Perecnt

patients

No.

patients

ITU +

Percent

patients

ITU+

No.

patients

Percent

patients

No.

patients

ITU +

Percent

patients

ITU+1 24 27.58 9 37.5 20 83.3 7 35 4 16.6 2 50

2 29 33.3 12 41.37 22 75.86 11 50 7 24.1 1 14.283 13 14.94 8 61 10 76.92 7 70 3 23.07 1 33.3

4 14 16.09 10 71 11 78.57 7 63.63 3 21.4 3 100

5 7 8.04 4 57 2 28.57 1 50 5 71.42 3 60

Total 87 100 43 49.42 65 74.71 33 50.7 22 25.28 10 45.45

HN = hydronephrosis; ITU + = presence of urinary infection

with UTI. (min = 1.26 months, max = 36 months),compared with only 4.64 months for patientswithout UTI (p = 0.0035, 95% CI).

Among patients with UTI under uroprophylaxis23 (60.52%) had urinary tract infections, 15 of themthe least one episode. In 5 patients who were given

intermittent prophylaxis the incidence of urinarytract infections was 80% (4/5).A cephalosporin was used in 51 cases, namely

Cefaclor in 50 pacients and Cefuroxime in onecase.

DISCUSSIONS

The risk of having a urinary tract infectioncorrelates with the degree of hydronephrosis. Theincidence of UTI may reach 40% in case of HN

grade IV (according to SFU grading Society ofFetal Urology) (6). We found a 71% rate (from63.63 to 100%) for grade IV HN.

Coehlo et al estimated that cumulative incidenceof UTI to be 39%, 18% and 11% by the age of 3years in case of severe, moderate and minor HNrespectively (7). Estrada reported an incidence ofUTI in patients with grade II HN only 3% (8). Forthe same degree of HN we found a frequency of41.27% (from 14.28 to 50%, depending on the

presence of unilateral or bilateral HN).

The American Association of Urology Guide-lines on screening and management of primaryvesicoureteral reflux (VUR) in children, revised in2010, in the section refering to the screening of new-

borns and infants with antenatal hydronephrosis, isreported an incidence of UTI between 0.5-21.3% (9).

We found a frequency of UTI of 49.42% inpacients with antenatal HN. However, only 11.49%(10/87) had a history of UTI prior inclusion in thisstudy.

UTI recurrence rate within 12 months after the

episode of urinary tract infections is 10-30% (2,10), compared with 53.48% in this study. Theincreased frequency offirst UTI and of recurrent

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UTI can possible be explained by a low compliance,many patients presenting in acute phase or aredetected during regular checks.

We didnt evaluated the type of malformativedefects as a potential risk factor for urinary in-fections.

The effi

cacy of uroprophylaxis in preventingUTI has not been proven (11). However, in arandomized study that evaluated the effectivenessin reducing the recurrence of urinary infections in

patients with or without primary VUR with a firsturinary tract infection, Craig et al. showed thatadministration of low doses of antibiotics (trime-thoprim sulfamethoxazole namely) was associatedwith a decrease of 6% in the number of urinaryinfections in children (12).

Of the 38 patients with UTI who received low

doses of antibiotics, 60.52% had urinary tractinfections on uroprophylaxis.However, routine uroprophylaxis is no more

recommended for infants diagnosed with antenatalhydronephrosis. Recent researchs recommend se-lective uroprophylaxis in case of severe HN (definedas anterior posterior diameter of renal pelvis DAP>15 mm), primary grade III-V vesicoureteral reflux,suspected obstruction (11,13).

Of the 17 patients without uroprophylaxis andUTI, 11 of them had first degree hydronephrosis

and one a patient grade II HN. This conservativemanagement for low-grade HN was implementedin the last three years (2008-2010).

Regarding the etiology of urinary infections, itdiffers depending on the presence or absence ofrenal and urinary abnormality and type.

In patients with or without primary VUR, E.Coli was involved in over 80-88% of cases (2.12,14), followed by Proteus in 4-5% of cases andKlebsiella in 3-4% (12). The overall incidence ofother Gram negative germs (Klebsiella, Entero-

bacter, Proteus, Pseudomonas) except E. coli in the

etiology of urinary infections is between 10-15%.Pseudomonas aeruginosa is a rare pathogen,usually being involved in the etiology of recurrentinfections (due to the use of broad-spectrum anti-

biotics) or in case of a renal and urinary diseases,the incidence of which is

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