Predictive Score for Dengue Infection with Complete Blood Count Parameters, Including the Monocyte Distribution Width: A Retrospective Single-Center Derivation and Validation Study

Early detection of dengue virus infection will lead to proper management and reduction in morbidity/mortality. Monocyte distribution width (MDW) was recently approved for use in the early detection of sepsis. Because monocytes are involved in the innate immune system against viral infection, we sought to determine changes in MDW to develop and validate a new predictive score for dengue viral infection. This study included patients who presented with symptoms or signs related to dengue infection and who had a complete blood count and dengue investigation performed during September 2019 to May 2020. The proportion of dengue infection was 29.5% in the current study. The MDW was significantly higher in dengue infection (median, 29.7 versus 24.2; P < 0.001). We then randomly separated patients into training and validation cohorts. Independent predictive factors of dengue infection were white blood cells < 4 × 109/L (score 1), platelets < 100 × 109/L (score 1), and MDW > 24 (score 1). Clinical features were not significantly predictive of dengue infection. The areas under the receiver operating characteristic curve (95% CI) of the prognostic score were 0.839 (0.779-0.899) in the training cohort and 0.742 (0.674-0.811) in the validation cohort. With a cutoff score ≥ 1, the sensitivity and specificity of the scores were 92.2% and 40.8% in the training cohort and 88.9% and 44.1% in the validation cohort, respectively. We concluded that MDW increases with dengue infection and MDW could easily be incorporated in the predictive scores for dengue infection.