Urine Analysis negative but Urine Culture positive for ecoli in 4 year old?

[A2010]

My 4 year old daughter has been experiencing lethargy and tummy pains for the last 7 days. She’s had 2 urine samples taken, one at the doctors which was completely clear, and one at the hospital which was sent to the lab and has come back positive for ecoli. I’m just puzzled how one can be negative and one is positive. Anyone have any ideas?

Because sometimes tests are incorrect? Does she have diverticulitis?

Was the one done at the doctors just a standard dip stick urinalysis? They don't test for specific infections.

False negatives can occur due to limitations with dipsticks/urine handling issues etc.

And presumably different days?

The one at the doctor's would be a simple dip test and the hospital will have run a different test to see if bacteria grow on the sample