What urine analysis result is indicative of a urinary tract infection (UTI) in children?

A positive dipstick test for nitrite or leukocytes is indicative of a urinary tract infection (UTI) because these findings are associated with bacterial infection in the urinary tract. Nitrites are produced when certain bacteria, especially those commonly associated with UTIs like Escherichia coli, convert nitrates (which are normally present in urine) to nitrites. Therefore, the presence of nitrites on a dipstick suggests bacterial activity.

Leukocytes, or white blood cells, are another key indicator. Their presence signifies an inflammatory response to infection, commonly seen in UTIs. When leukocytes are detected in the urine, it suggests that the body is responding to an infection in the urinary system.

In the context of the other options, increased blood urea nitrogen is not specific for UTIs and can be affected by various other conditions, including kidney issues or dehydration. Negative culture results would typically indicate that there is no bacterial growth, thus not supporting a diagnosis of a UTI. The presence of glucose in urine is indicative of conditions such as diabetes mellitus but is not diagnostic of a UTI.

Thus, a positive dipstick result for nitrite or leukocytes provides a clear indication of a urinary tract infection in children.