What does a negative nitrite result on a urinalysis indicate?

A negative nitrite result on a urinalysis indicates the absence of bacteria capable of converting nitrates to nitrites, which is a common characteristic of urinary tract infections (UTIs). Most bacteria that cause UTIs, particularly those in the Enterobacteriaceae family, have the enzymatic ability to reduce nitrates to nitrites. Consequently, a negative nitrite result strongly suggests that there is no active bacterial infection present in the urinary tract.

In addition to indicating the absence of certain bacteria, a negative nitrite result could further support the conclusion that the urine is likely sterile at the time of testing. This makes it an important result when assessing patients for UTIs, as the presence of nitrites would typically be an indicator of infection. It's also worth noting that while a negative nitrite result suggests low likelihood for a UTI, it doesn't rule out other causes of urinary symptoms, as not all urinary tract pathogens produce nitrites.