Long-term consequences of urinary tract infection in Childhood (LUCI): Electronic population-based cohort study

Conference:

SAPC ASM 2023 - Brighton

Talk Code:

3A.4

Presenter:

Kathryn Hughes

Co-authors:

Rebecca Cannings-John, Hywel Jones, Fiona V Lugg-Widger, Tin Man Mandy Lau, Shantini Paranjothy, Nick Francis, Alastair D Hay, Christopher C Butler, Lianna Angel, Judith Van der Voort, Kerenza Hood

Author institutions:

Cardiff University, University of Aberdeen, University of Southampton, University of Bristol, University of Oxford, Noah's Ark Children's Hospital for Wales

Problem

Childhood urinary tract infection (UTI) can cause renal scarring and possibly long-term complications including hypertension, chronic kidney disease (CKD) and end-stage renal failure (ESRF). Previous studies are generally of selected populations, with severe illness or high rates of underlying risk factors, and rates of renal scarring vary widely. The risk of renal scarring for most children with UTI, without additional risk factors, and those commonly seen in primary care, is not known. The aims of this study were to examine the association between childhood urinary tract infection (UTI) and long-term adverse outcomes in an unselected population of children.

Approach

This was a retrospective, population-based cohort study, linking primary care, hospital and microbiology records in Wales, using the Secure Anonymised Information Linkage Databank (SAIL). All children born in Wales between 2005 and 2009 were included in the study with a mean follow-up period of 10 years (until date of death or migration, or December 2017). The exposure was one or more microbiologically confirmed urinary tract infections (UTI) before the age of five years in any setting. The primary outcome was renal scarring and key secondary outcomes included hypertension, chronic kidney disease (CKD) and end-stage renal failure (ESRF). We adjusted for underlying risk factors including vesicoureteral reflux disease (VUR), congenital conditions and comorbidities.

Findings

Of the 159,201 children included in the study, 48·7% were female and 11,099 (7%) had one or more microbiologically confirmed UTI before age five. Of the 10,875 children with at least seven years follow-up, 135 (1·24%) were diagnosed with renal scarring by age seven (compared to 110/145,509 (0·08%) in children without UTI). Renal scarring was over four times higher in children with UTI (adjusted odds ratio 4·60, 95% CI: 3·33 to 6·35). There was no association between childhood UTI and hypertension, CKD or ESRF up to age ten after adjusting for underlying risk factors (adjusted hazard ratios (95% CI): hypertension 1·44 (0·84 to 2·46), CKD 1·67 (0·85 to 3·31) and ESRF 1·16 (0·56 to 2·37)).

Consequences

Childhood UTI is associated with a diagnosis of renal scarring in an unselected population of children, but the prevalence is low. UTI is not associated with CKD, hypertension or ESRF by age 10. Further research with systematic scanning of children’s kidneys including those with less severe UTI and without UTI, is needed to increase certainty of the causal pathway, as most children without UTI are not scanned. Longer follow-up is needed to establish if UTI, without additional risk factors, is associated with hypertension, CKD or ESRF later in life.

Submitted by:

Kathryn Hughes

Funding acknowledgement:

This project was funded by the Welsh Government through Health and Care Research Wales.