The presence of nitrites in the urine is normal with a negative result, and a positive result suggests the possible presence of a urinary tract infection. Further confirmation of the diagnosis is needed in conjunction with indicators such as leukocytes and leukocyte esterase in the urinary tract. When the urinary tract is infected with Escherichia coli, or other enterobacteria, it can reduce nitrates to nitrites, so a positive result for nitrites is seen. This is usually accompanied by an elevated urine leukocyte count, or a positive result for leukocyte esterase. And the patient may have urinary tract irritation symptoms such as urinary frequency, urinary urgency, and painful urination. Further urine culture needs to be retained and anti-infective treatment is required. However, there are false positive results for nitrite in urine, too. If there is a high amount of vitamin C present in the urine, this can show a positive result for nitrite, but then it is not a urinary tract infection, but the vitamin C reduces the nitrate to nitrite, causing a false positive.