The Role of Neutrophil to Lymphocyte Count Ratio, Erythrocyte Sedimentation Rate and Total White Blood Cells in the Differential Diagnosis of Pulmonary Tuberculosis and Bacterial Community-Acquired Pneumonia at public Hospitals in Mekelle, Mekelle, northern Ethiopia

Abstract

ABSTRACT Introduction: In countries with a high Tuberculosis(TB) burden, the differential diagnosis of TB from pneumonia is difficult. Objectives: To evaluate the role of NLCR in the differential diagnosis of pulmonary Tuberculosis(PTB) and bacterial Community Acquired Pneumonia(CAP) at Ayder comprehensive specialized hospital and Mekelle general hospital, Mekelle, Ethiopia. Methods: A hospital based cross-sectional study was conducted from February to May, 2017. A quota sampling technique was employed. Complete blood cell counts was determined before antibiotic treatment using a Sysmex XT-4000i Hematology Analyzer. Erythrocyte sedimentation rate(ESR) was done using westergren method. The Ziehl- Neelsen technique and Gene X-pert were used for testing PTB and sputum culture for bacterial CAP. Student’s t-test, Pearson’s chi square test and Receiver operating characteristics (ROC) curve analysis were used. A P value ?0.05 was considered statistically significant. Result: The NLCR and ESR were significantly higher among PTB patients than bacterial CAP patients. But, total white blood cell(TWBC) count was not significantly different in these two groups of patients. Using NLCR together with ESR at their respective cut-off values (?2.72 and ?39) was seen to have largest area under the curve(AUC) (AUC =0.69; 95% Confidence Interval(CI): 0.62, 0.77)). But, based on test for equality of ROC curve areas, it was not significantly higher than that of the NLCR (0.644; 95% CI: 0.555, 0.733) and ESR (0.67; 95% CI: 0.582, 0.759) (P-value=0.29). However, TWBC was found to be not a parameter indiscriminating PTB from bacterial CAP (P-value>0.05). Conclusion and recommendation: When using ESR and NLCR together at a time with their respective cut off values gives of 69% accuracy in differentiating PTB patients from bacterial CAP patients. Therefore, the use of ESR and NLCR in routine laboratory examination in differentiating PTB from bacterial CAP is advisable especially in resource limited settings