Evaluation of classic biochemical and hematological markers in the differential diagnosis of dengue and other febrile diseases

Abstract

 Dengue is a prevalent viral disease worldwide, with reported cases to the WHO increasing from 505,430 in 2000 to 5.2 million in 2019. This disease contributes significantly to morbidity and mortality across all age groups. Alterations in biomarker levels during dengue infection provide valuable insights into early diagnosis and disease progression. This study aimed to evaluate the utility of biomarkers in distinguishing dengue infections from other febrile illnesses. We conducted a descriptive analytical study using a nested case-control design among febrile patients. Clinical data were obtained through epidemiological forms, and dengue-positive patients (n=43) confirmed by molecular tests were compared with febrile patients (n=45) negative for dengue. Blood samples were collected during the acute phase of illness to assess levels of serum electrolytes, total proteins, hematocrit, platelets, and other hematological parameters. Using statistical tests, we analyzed sociodemographic, clinical, and laboratory variables in the population. We found that the average age among dengue cases was 21.0 years with a standard deviation of 12.9. The most frequent symptoms observed in cases were headache (p=0.02), joint pain (p=0.049), retro-orbital pain (p=0.045), rash (p=0.009), and epistaxis (p=0.009). Significant differences were observed between the means of cases and controls in several parameters: white blood cell count (p=0.011), platelet count (p <0.001), mean corpuscular volume (MCV) (p=0.021), lymphocyte percentage (p < 0.001), neutrophil percentage (p < 0.001), and total proteins (p=0.011). The platelet count was identified as the best predictor of dengue in the acute phase of infection, with a sensitivity of 88% and specificity of 70% using a cut-off value of <175,500 mm³. The percentage of neutrophils and lymphocytes also showed sensitivity values equal to or greater than 70%.