[Leucocyte esterase as a reliable diagnostic, cost-effective and fast in knee infections]

The articular infection represents a challenge due to its complexity and its devastating effect when not treated promptly. We have various diagnostic studies: cultures, ESR, CRP, count of leukocytes, among others but none is specific, it takes more than 30 minutes to complete and require complex infrastructure. In this study we determine the sensitivity and specificity of the leukocyte esterase for detection of an infectious process joint in Mexican population.

From November 2015 to April 2016 was obtained synovial fluid from patients with diagnosis of knee infection with or without implant and without infection with degenerative pathology of the knee. It assessed the sample through the COMBI-SCREEN 11SYS leukocyte esterase with reading colorimetric test at two minutes determining positive for infection: two crosses, the remainder of the sample was sent to culture.

We perform the test in 64 samples of synovial fluid of knee joint 19 diagnosed with infection and 45 without infection. Was obtained a sensitivity 100%, specificity of 88.24%, PPV 68.42% and PNV 100%, kappa index 0.753 using the program IBM SPSS Statistics 22, Python ver. 2.7.

Leukocyte esterase is a fast, economical and effective to detect an infectious process against one inflammatory with high probability of success. This study showed an index of concordance 0.753 Kappa, proving to be reproducible so recommend be implemented in the emergency department at the national level.