A clear and colorless CSF from a lethargic and feverish 2 ye

A clear and colorless CSF from a lethargic and feverish 2 year old is sent to the lab. A cell count on the undiluted specimen reveals 860 WBC’s and 60 RBC’s in the 9 mm2 squares of the hemacytometer. A gram-stain reveals 90% neutrophils and 10% lymphocytes. Based on these results 1) what are the cell counts? 2) what would be the suspected condition/diagnosis? 3) can you infer if this is bacterial or viral in nature and why?

Solution

Answer

WBC count (per 9mm²) = 860

WBC count (per 1mm²) = 1 * 860 / 9

= 95.56

RBC count (per 9mm²) = 60

RBC count (per 1mm²) = 1 * 60 / 9

= 6.67

Answer 1

% Neurophils = 90

No. of Neutrophils = 90 * 95.56 / 100

= 86.004

% Lymphocytes = 10

No. Lymphocytes = 10 * 95.56 / 100

= 9.556

Answer 2

The suspected condition could be an inflammation in the brain that has caused the WBC counts to be raised to such an extent. Infammation could be due to any microbial infection.

Answer 3

Usually in a bacterial infection neutrophils would have increased above 1000 cells per mm² also the amount of neutrophils would be predominant. In this case such a high increase is not observed, although the amount of neutrophils are predominant.

Similarly in the case of a viral infection lymphocytes would be around 100 cells per mm² also the amount of lymphocytes would be predominant. In this case the lymhocyte amount is not predominant but the number of lymphocytes are around 100 cells per mm².

Therefore to infer whether the infection is viral or bacterial in nature further tests must be done.