Dr. Barry Chang

A urinary tract infection, UTI, can spread to the kidney via blood stream or if there are associated anatomical/functional abnormalities such as vesicoureteral reflux, neurogenic bladder, urinary obstruction, presence of kidney stone etc. The time it takes from bladder infection, cystitis, to kidney infection, pyelonephritis, may take anywhere between 24 to 72 hours. This can also be affected by that person's immunity state, and other factors as mentioned before. Pyelonephritis can lead to renal scarring and compromising renal function. It should be treated with IV antibiotic followed by the oral form as early as possible.

There are many reasons for a child, boy or girl, to have UTI. This can be caused by either an underlying medical condition such as urinary reflux, or simply a behavior-related issue such as "lazy bladder." Without a proper clinical evaluation and imaging study, sometimes it is difficult to determine the true cause. I would recommend taking your daughter to the pediatrician first. He or she may request a pediatric urology consult if necessary.

Thank you.

Your pediatrician may be correct because some UTIs, especially in her age group, are caused by either gastrointestinal such as constipation or behavior, such as bladder holding, issues. These issues can be treated conservatively. I would recommend a properly collected urine culture in the future to determine if it is truly an infection before ordering any imaging studies. thank you

Painful urination in a boy may not necessary caused by UTI, unless there is a positive urine culture that showed bacterial infection. Other causes can be meatal stenosis, bladder spasm from prolong holding, high acidic urine from dehydration etc. A good physical examine and urine analysis may reveal the cause. thank you

Vesicoureteral reflux, or VUR, tends to run in the family but there is no genetic component as to date. Your son may have an abnormal ureteral anatomy that leads to VUR, or he simply has a voiding dysfunction, such as holding urine for a long time, which can lead to secondary VUR. A well trained pediatric urologist can determine the real cause(s). thank you

A dirty diaper can increase the risk of UTI in a girl simply because of the short urethra in female anatomy. Bacteria in the stool can get into the lower urinary tract causing "ascending" infection. This is similar in an uncircumcised boy where bacteria can colonize under the foreskin and lead to infection. Check her diaper more often!

Thank you.

Generally speaking, no, as long as the diaper is clean. However, a dirty diaper can lead to ascending urinary tract infection in a girl because female urethra is very short, and bacteria can get into the bladder easier than a boy. If you keep her in a clean diaper regularly, it should be fine. Thank you.