There are several practical reasons why dipstick and urine culture tests can miss the
presence of infection:

​

• Antibiotics that partly clear an infection will reduce the levels of bacteria in your urine.

• Drinking a lot to try to flush out an infection will dilute your urine.

• Bacteria that have moved into the cells of the bladder wall – which happens in chronic UTI – are not detected by these tests.

• But there are also serious problems with the way the tests were designed and how they are interpreted.

MSUs identify which types of bacteria are present in the urine and in what numbers by
growing them in a petri dish in a laboratory.
​
The use of MSUs and dipstick tests to diagnose UTIs are based on research by a scientist
called Kass from the 1950s.

​

New research says the opposite!

​

A healthy bladder is not sterile. Just like the gut, the bladder has its own balance of good and bad bacteria called the ‘urinary biome’. Our bladder contains about 500 different types of bacteria which usually coexist happily, with a large overlap with disease. A culture cannot identify which of those bacteria are causing an infection.

​

​

Newer tests can detect bacteria with much better sensitivity.

They are, essentially, a better way to do what cultures do. However, the use of urine cultures for managing UTI is predicated on a faulty premise to begin with, and doing it better does not solve that problem.

Thus, while such tests are a useful research tool, they are presently useless for clinical management.