Comprehensive investigation of fever cases enrolled during 2019 dengue outbreaks from three hyperendemic regions of North 24 Parganas district of West Bengal, India.

For the past several decades, dengue fever has been emerging in epidemic proportions in several regions of the world. During August-September 2019, an increasing number of fever cases were being reported from some areas of North 24 Parganas district of West Bengal, India. Accordingly, outbreak investigation of fever cases from these affected areas of Bongoan, Barasat, and Habra was carried out. To characterize clinical and biochemical features of fever cases as well as to investigate the utility of CRP as a Dengue severity marker in resource-limited settings. We systematically enrolled 108 patients from the affected region of North 24 Parganas. Standard diagnostic assays along with routine serological and biochemical parameters were performed. Of the 108 patients, 77 (71%) were confirmed with Dengue infection followed by 22 (20%) DENV seronegative and 9 (8%) coinfected DENV cases. Among the 77 confirmed Dengue patients, 53 (69%) had primary infection while 24 (31%) had secondary infection. Among the DENV clinical symptoms, fever (r = 0.50; p = 0.004), headache (r = 0.40; p = 0.03) and abdominal pain (r = -0.40; p = 0.02) were found to bear significant correlation with DENV viral load. The predominant circulating serotype was found to be DENV2. CRP Dengue severity cut-off level of 10.15 mg/L (AUC: 0.85; 86% sensitivity, 77% specificity) was obtained. CRP had correlation with viral load (r = 0.4, p = 0.05) within febrile phase of infection. The performance of biomarkers can be influenced by local epidemiology, geography, and several patient factors, therefore, CRP Dengue severity cut-off value may be region-specific. This study for the first time attempts to estimate CRP Dengue severity cut-off value based on routine immunoturbidometric evaluation from Dengue Hyperendemic zones of North 24 Parganas, West Bengal, Eastern India.