Distribution of Dengue Virus Serotypes and Genotypes Circulating in and around Bhopal Region

Abstract

Dengue has been reported to be the most rapidly spreading mosquito-borne viral disease that causes approximately 400 million cases and 25,000 deaths each year. In sync with increasing incidence, the disease has also spread to newer regions of the world with endemicity being observed in gt100 countries. India too has witnessed a rising burden of Dengue. The public health importance of Dengue is also contributed by the development of life-threatening complications like DHF and DSS. A total of 1271 patients with dengue confirmed by serology were enrolled in this study, over a period of 36 months (2016 to 2018). The mean age of all the patient was 28±15 years with 67.20% males and 32.80% females. We observed significantly higher positivity by RT-PCR in 0-3 (days), compared to patients positive by RT-PCR test gt3 days of illness. In this study, DENV RNA was detected in serum of 395 (31%) patients. In 2016, DENV1 was the most dominant (47.36%) serotype followed by DENV2 (38.60%) with very few DENV3 and DENV4 was completely absent. However, in 2017 drastic change in predominant serotypes was observed, DENV3 (50.58%) serotype was replaced with emergence of DENV4 (30.58%) followed by equally DENV1 and DENV2. In 2018, DENV3 was continued as dominant (85.72%) serotype followed by DENV1 (10.98%) and few sporadic cases of DENV2 and DENV4, respectively. For genotypic analysis, we have successfully sequence 73 RT-PCR-positive samples (representative of all 4 serotypes). The genotype V of DENV1, cosmopolitan genotype of DENV2, genotype III of DENV3 and genotype I of DENV4 was identified to be the circulating genotypes. Characterization of the circulating strain is extremely valuable because it provides crucial information about the virulence of the circulating DENV strain, aids in the prediction of future dengue outbreaks and equips us with the knowledge needed to develop newer strategies for the development of an ideal vaccine. newline