A method for distinguishing erythroblasts from bacteria by automated hematology analyzers, such as, for example, the CELL-DYN® 4000 automated hematology analyzer and the CELL-DYN® Sapphire™ automated hematology analyzer. Bacterial cells scatter light and fluoresce differently than do red blood cells, white blood cells, erythroblast nuclei, and platelets. Signals generated by bacteria are distinguishable from those of erythroblasts because the signals generated by erythroblast nuclei are sufficiently unique that erythroblast nuclei can be distinguished from signals generated by bacteria. Signals generated by platelets, lysed red blood cell ghosts, and other cell debris are blocked by the triple-trigger circuitry of the hematology analyzer, because all of the signals generated by noise are below the AND/OR thresholds. Algorithm(s) in the software of the system detect and count signals generated by bacteria by means of the location and the shape of the signals generated by bacteria and calculate the concentration of bacteria per unit of body fluid. In addition, certain body fluids, such as, for example, synovial fluid, can be pretreated with a viscosity reducing agent for a short period of time to reduce the viscosity of the body fluid prior to analyzing a sample of the body fluid by an automated hematology analyzer.