Dengue Serotype and Genotype 2019 Dhaka outbreak

Background: Acute arboviral infections like dengue have a significant negative socioeconomic and health impact on many tropical and subtropical areas of the world. 3.9 billion Individuals are at risk of contracting the dengue virus, with Asia bearing the brunt of that load. Bangladesh, like other south-east Asian countries faced a massive outbreak of dengue in 2019. The purpose of this study was to describe the clinical and laboratory variations among severe dengue cases and to conduct a serotype survey and forecast future changes in the clinical or serological profile of this virus. Methods: This cross sectional study was done in three tertiary care centers in Dhaka, Bangladesh during the worst outbreak of dengue in this hyperendemic region spanning from 1st August to 31st December, 2019. The study enrolled 1978 participants who were grouped into group B and C according to national guidelines. Thus, the clinical and laboratory difference between these two groups are described. Furthermore, 81 samples were serotyped using Qiagen One step RT-PCR kit (Cat. No: 210212). In addition sequencing (ABI sequencing platform) of partial C-prM gene of five DENV-3 isolates were done and analyzed (BLAST tool of NCBI) for phylogenetics (MEGA6 software package Results: Among the 1978 enrolled participants group B and C patients were 1580 (80%) and 398 (20%) respectively. The median (IQR) age of the patients were 26(11 to 41). Maximum proportion of the enrolled were male (72.2%) (p=0.0002). Median (IQR) of the cohort was 26(11 to 41). Only 5.56% were secondary infections. Group C patients more commonly presented with vomiting (p 0.133), diarrhea (p<0.0001) and abdominal pain (p 0.0203). Most common co- morbidities were hypertension (90; 4.55%) and DM (70; 3.54%). The major mode of bleeding was melaena (12%). Only 13 (0.66%) patients succumbed to death, 12 of them belonged to group B. Hemoglobin and hematocrit was lower in group C cases (p 0.004 and 0.006 respectively). Aspartate transaminase was higher in the same group (p 0.0016). Fluid requirement was higher in group C (p<0.0001) and platelet requirement was more in group B (0.0070). Only 12 (0.7%) required ICU. Only one patient got antibiotics and none were managed by steroids. Out of 81 samples 79% patients were serotyped as DENV-3, followed by DENV 2,3 (13.6% ) and DENV-2 (7.4%). Following phylogenetic analysis DENV-3 and DENV2 were deemed to be of genotype I and cosmopolitan variety. Conclusions: This study presents the first instance of heterogeneous co-infection with several serotypes since 2000 in Bangladesh. It also gives an overview of serotype prevalence, management evaluation and clinical results that promises to navigate future control planning.