Molecular Identification of Dengue Virus Strains in Laboratory-Confirmed Dengue Cases

Dr K Preethi; Alice Peace Selvabai R; Priyadarshini Shanmugam

doi:10.24321/10.24321/0019.5138.202590

Dr K Preethi Post graduate Tutor, Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, India
Alice Peace Selvabai R Professor,Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, India
Priyadarshini Shanmugam Professor and Head, Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, India

DOI: https://doi.org/10.24321/10.24321/0019.5138.202590

Keywords: Haemorrhagic fever, Molecular typing, Non-structural antigen, ICT, ELISA

Abstract

Abstract

Background: Dengue fever is a rapidly spreading arboviral infection caused by Dengue Virus, which had 4 antigenically distinct (DENV) serotypes—DENV1, DENV2, DENV3, and DENV4—transmitted by Aedes mosquitoes. Identification of circulating serotypes and their correlation with disease severity, outbreak prediction and clinical management may be necessary, to initiate therapeutic, preventive and control measures. While NS1 antigen and IgM/IgG antibody tests are the widely used serological tests for diagnosis, RT-PCR provides definitive serotype identification.

Methodology: This study was performed at Chettinad Hospital & RI between June 2023 to December 2023. A total of 100 laboratory-confirmed dengue-positive patients were included. Diagnosis was based on NS1 antigen and IgM/IgG antibody positivity using Immunochromatography card tests and ELISA method. RT-PCR (HELINI Dengue Genotyping Kit) was employed to detect and differentiate DENV1 to DENV4.

Results: Among 100 patients, 69% were males and 31% were females. The majority of the positive cases belonged to the 11–30 years of age group. NS1 antigen positivity was observed in 89%, and IgM in 30%, 19 patients showed dual positivity. RT-PCR was positive in 36 patients and DENV3 was the predominant serotype. Three individuals were positive for the DENV-4 serotype. Five individuals were co-infected with the DENV-3 and DENV-4 serotypes.

Conclusion: DENV3 was the most prevalent serotype in this study. Young males were disproportionately affected. RT-PCR-based serotyping enhances diagnostic accuracy and supports informed clinical decisions during dengue outbreaks.

Keywords: Haemorrhagic fever, Molecular typing, Non-structural antigen, ICT, ELISA.

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