Millions of women — and young girls — suffer from urinary tract infections that keep coming back, no matter how long they’re treated.Now, researchers think they may know one reason why.Growing evidence suggests chronic UTIs may be caused by bacteria that dig into the bladder wall, out of reach of antibiotics and the immune system.Chronic UTIs can start as early as age five. By definition, that means two or more infections within six months.In a recent case study, doctors followed a teenage girl who’s been battling chronic UTIs since childhood, and found the E.coli causing her infections had buried itself in her bladder lining, making treatment ineffective.The researchers say these findings point to an urgent need for new medications — and better data. To help, they’ve launched a new database tracking UTIs in children younger than 15.The lead author says, “The longer consequences of persistent UTIs can be severe,” including chronic pain. incontinence, kidney disease, and sexual and pregnancy complications.Source: ASM Case Reports. Author Affiliations: University of Sydney.Sign up for our weekly HealthDay newsletter