Serotype and genotype shift detection over two consecutive periods of dengue virus infection in a tertiary care hospital.

PURPOSE: Dengue virus infection in humans can also lead to severe complications like dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The World Health Organization (WHO) estimates around 50 to 100 million dengue infections annually, with approximately 500,000 cases of DHF and 22,000 deaths, predominantly among children. The present study aimed at identifying circulating serotypes of dengue virus in patients by molecular techniques. Serotypes detected were correlated with the clinical profiles, complications, and outcomes in these patients.

METHODS

This study was conducted between October 2019 to September 2022. Institute Ethics Committee approval was obtained (Reference no. IEC: RC/18/59). Serum from patients who tested positive for dengue NS1 antigen (NS1Ag) or anti-dengue immunoglobulin M (IgM) were serotyped by dengue reverse transcriptase polymerase chain reaction (RT-PCR). Clinical data was documented in case report forms and transferred to an Excel spreadsheet, and subsequently analyzed to correlate the dengue virus (DENV) serotype with clinical profile and outcome.

RESULTS

The study population included 416 patients, confirmed by Dengue NS1Ag and or anti-Dengue IgM ELISA. Young adults (18-29 yrs) constituted the majority (56 %) of patients. About 85 % of all patients presented with fever, 10.6 % with hemorrhagic fever, and 4.4 % with shock syndrome. Thrombocytopenia with multiple bleeding manifestations was observed in 6.5 % of the patients. The predominant dengue serotype identified was serotype 3 from October 2019 to March 2021, and serotype 2 from April 2021 to September 2022, showing a shift in the serotypes affecting the patients.

CONCLUSION

Continuous sero- and molecular surveillance plays a crucial role in predicting dengue outbreaks and identifying shifts in circulating serotypes during the early phase of the dengue season. It may also play a role in vaccine preparedness for the control of dengue.