Novel insights into urinary tract infections in children
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
University of Oulu, Kontinkangas Welfare Campus, Auditorium F202
Topic of the dissertation
Novel insights into urinary tract infections in children
Doctoral candidate
Medical Doctor Mikael Hakkola
Faculty and unit
University of Oulu Graduate School, Faculty of Medicine, Research Unit of Clinical Medicine
Subject of study
Medicine
Opponent
Docent Timo Jahnukainen, HUS, New Children's Hospital
Custos
Professor Terhi Ruuska-Loewald, University of Oulu
Novel insights into urinary tract infections in children
In this dissertation we show that cranberry-lingonberry juice used in prevention of urinary tract infections changes the composition of both gut and urinary microbiome in children. We observed that antibiotics administered to mother during labour are associated with increased infection risk in the offspring during the first five years of life. We also noticed that restricting urinary tract ultrasound screening after a urinary tract infection to only infants may lead to missing significant anatomical abnormalities of the urinary tract.
Our purpose was to search for new knowledge about prevention and risk factors of urinary tract infections in children and to also asses the benefits of urinary tract ultrasound screening used after urinary tract infections. Research into urinary tract infections in children is important because they are common during the childhood and their treatment often requires hospitalisation.
In the first study we looked into effects of cranberry-lingonberry juice on gut and urinary microbiome in children. In previous studies cranberry-lingonberry juice has been shown to be effective in prevention of urinary tract infections in children. In this study we found out that children who drank cranberry-lingonberry juice had different composition of the gut and urinary microbiome compared to children who drank placebo juice, which did not contain berries.
In the second study we observed the effect of antibiotics administered to mother during the labour on the risk of infections in the offspring during the first five years of life. Administration of antibiotics to mothers have become more common as they have been shown to be effective in prevention of severe group B streptococcus infection in new born children. In the study administration of antibiotics to mother was associated with increased risk of infection leading to hospitalisation in the offspring. Risk of urinary tract infections separately also seemed to be increased, but there seemed to be no association to severe infections.
In the third study we explored the urinary tract ultrasound screening after a urinary tract infection, which is used to search for anatomical abnormalities of the urinary tract that could cause urinary tract infections in children. Currently, many international guidelines recommend ultrasound screening after a urinary tract infection only for infants. In our study restricting ultrasound screening only to infants would have lead to missing some significant abnormalities.
Our purpose was to search for new knowledge about prevention and risk factors of urinary tract infections in children and to also asses the benefits of urinary tract ultrasound screening used after urinary tract infections. Research into urinary tract infections in children is important because they are common during the childhood and their treatment often requires hospitalisation.
In the first study we looked into effects of cranberry-lingonberry juice on gut and urinary microbiome in children. In previous studies cranberry-lingonberry juice has been shown to be effective in prevention of urinary tract infections in children. In this study we found out that children who drank cranberry-lingonberry juice had different composition of the gut and urinary microbiome compared to children who drank placebo juice, which did not contain berries.
In the second study we observed the effect of antibiotics administered to mother during the labour on the risk of infections in the offspring during the first five years of life. Administration of antibiotics to mothers have become more common as they have been shown to be effective in prevention of severe group B streptococcus infection in new born children. In the study administration of antibiotics to mother was associated with increased risk of infection leading to hospitalisation in the offspring. Risk of urinary tract infections separately also seemed to be increased, but there seemed to be no association to severe infections.
In the third study we explored the urinary tract ultrasound screening after a urinary tract infection, which is used to search for anatomical abnormalities of the urinary tract that could cause urinary tract infections in children. Currently, many international guidelines recommend ultrasound screening after a urinary tract infection only for infants. In our study restricting ultrasound screening only to infants would have lead to missing some significant abnormalities.
Created 16.11.2025 | Updated 17.11.2025