Accuracy and applicability of the revised WHO classification (2009) of dengue in children seen at a tertiary healthcare facility in northern India

Revised case definitions of dengue into dengue with/without warning signs (DWS/D) and severe dengue (SD) was proposed by the World Health Organization (WHO)/Tropical Disease Research (TDR) in 2009. To date, there has been no Indian study that has applied this classification. To assess the accuracy and applicability of the revised WHO classification (2009) of dengue in children seen at a tertiary healthcare facility in India. Over a period of 1 year children from the pediatric ward and Out Patient Department (OPD) of the King George Medical University Hospital, Lucknow were enrolled in the study according to predefined criteria and tested for dengue. Each dengue-positive patient was classified according to both the older system [dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS)] and the new system (D, DWS, and SD). The severity of dengue was compared to the level of treatment received. A total of 56 patients tested positive for dengue-51 from the pediatric ward and five from the OPD. According to the older WHO classification, 42 (75 %) patients were classified as DF and 13 (23.2 %) as DHF/DSS; one patient was unclassifiable. Five patients (8.9 %) received level 1 treatment, ten (17.8 %) received level 2 treatment, and 41 (73.2 %) received level 3 treatment. According to the new WHO/TDR classification, 46 (82.1 %) patients were classified as SD, nine (16 %) as DWS, and only one (1.7 %) as D. Many of the severe manifestations (encephalopathy, shock, mucosal bleed, platelet count < 20,000, respiratory distress, liver enzymes > 1,000 U/L) were seen in patients who were classified as DF according to old classification, whereas these patients were mostly classified as SD by the new classification. Sensitivity of the older and new classifications was 24.8 and 98 %, respectively. The revised WHO/TDR (2009) classification has very high sensitivity for identifying severe dengue and is easy to apply.