Evaluation of diagnostic assay of patients with enteric fever by the box-plot distribution method

Abstract

Enteric fever is an invasive bacterial infection mostly caused by Salmonella enterica serovar Typhi, which is a common agent of enteric fever. This illness has been a major public health issue, as it affects a large number of individuals globally. The box-plot analytic method is involved in exploratory data analysis using statistical techniques to identify patterns that may be hidden in a group of numbers used to visually summarize and compare groups of data. We evaluted the effect of enteric fever on various haematologic parameters using the box-plot distribution model. Samples were obtained from 400 volunteer patients as well as healthy subjects (controls). Assay for typhoid fever was carried out using obtained serum samples to detect specific O and H antigens. Antibody titres of 1:80 and higher for anti-TO and 1:160 and higher for anti-TH antibodies were taken as cutoff values to indicate recent infection of typhoid fever. The haematologic parameters were evaluated using an automated haematology analyser. A statistically significant decrease was observed in packed cell volume, white blood cell count, erythrocyte sedimentation rate and haemoglobin concentration, while a statistically insignificant difference was observed in the neutrophils, lymphocytes and monocytes seen in the box-plot distribution analysis. Typhoid fever causes significant haematologic changes which could be helpful in diagnosis. The box-and-whisker plots compared the distributions of the haematologic parameters, spread and overall ranges. Awareness of these parameters could be useful in providing accurate diagnosis and therapy, particularly in underresourced endemic regions in developing countries.

Keywords

• Box-plot distribution
• diagnostics evaluation
• enteric fever
• haematological indices
• salmonella spp