Evaluation of mean monocyte volume in septicemia caused by Salmonella species.

OBJECTIVE: The objective was to study the significance of volume, conductivity, and scatter (VCS) parameters of monocytes in Salmonella infection.

MATERIALS AND METHODS: We selected peripheral blood samples of 52 patients whose blood culture was positive for Salmonella species ( Salmonella typhi and Salmonella paratyphi A ) and analyzed VCS parameters by subjecting them to differential count in hematology analyzer LH750 (Beckman Coulter). Out of these, we studied VCS parameters of monocytes in Salmonella infection and compared with two control groups (control 1: other infections and control 2: normal subjects).

RESULTS: Mean monocyte volume (MMV), standard deviation (SD) of MMV, and SD of mean channel monocyte conductivity were found to be significantly increased in Salmonella infection ( P < 0.05) when compared with both controls. We propose a cutoff value of 185 for MMV with sensitivity and specificity of 80% and 73%, respectively, to predict Salmonella infection.

CONCLUSIONS: MMV can be a useful tool for predicting Salmonella infection under appropriate clinical settings.