A new look at an old test may provide earlier detection of meningitis

Nov. 7, 2013

Researchers from the University of Missouri School of Medicine assert they have found a more accurate method to screen for bacterial meningococcal infection in its early stages.

Diagnosis of most bacterial infections traditionally has relied upon the detection of an increase in the total number of white blood cells. However, in their study of 216 cases from the U.S. Multicenter Meningococcal Surveillance Study, MU researchers found that 33% of patients with active infections had total white blood cell counts that appeared normal. After examining the patients’ blood tests more closely, researchers found that a better indicator of infection was abnormalities in neutrophils.

“When we looked at the neutrophil counts of each patient, we examined not only the total number of neutrophils, but also the number of immature neutrophils and the ratio of immature to total neutrophil cells,” says Michael Cooperstock, MD, senior study author. “We found that 94% of patients showed an abnormality of one or more of these three tests. Reliance on the total white blood cell count alone would have given false reassurance that infection was not present in more than 30% of those cases. Our study suggests that physicians should look at the total number of neutrophils, the total number of band neutrophils, and the ratio of band to total neutrophils as an indicator that could lead to a suspicion of meningococcal infection.”

Cooperstock also points out that although automated white cell counts, a method used in many emergency rooms and clinics, may be quicker, they do not measure neutrophil bands and could lead to a missed diagnosis. Read the study abstract.