Rapid diagnosis of bacterial meningitis using nitrite patch testing

Urine reagent strips have been used to test cerebrospinal fluid (CSF) in areas where laboratory facilities are unavailable. Protein, glucose and leukocyte esterase patches have been shown to be useful in this context. We propose that the nitrite patch also has a contribution to make: it could provide clinically useful information, at no extra cost. We tested CSF samples from 200 children with suspected meningitis. In a pragmatic approach chosen to reflect the clinical dilemma of whether or not to use parenteral antibiotics, the final laboratory diagnosis was dichotomized into either 'bacterial meningitis' or 'not bacterial meningitis'. These diagnostic categories were compared with nitrite patch results, which were either positive or negative. Nitrite patch testing of all CSF, clear CSF and bloody CSF gave positive likelihood ratios of 49, 'infinity' and 5.8, respectively.