A modified nitrite test as a screening test for significant bacteriuria

The presence of nitrite was initially assessed in 306 specimens of urine. If the initial result was negative a sample of urine was incubated at 37 degrees C. The other portion was also incubated but with the addition of one drop of 1% NaNO3, and the nitrite test was then repeated. The results were correlated with the results of quantitative routine urine culture. The modified test significantly (P less than 0.01) improved the sensitivity (93% v 21%), and the predictive negative value (97% v 80%).