Publication: Molecular Investigation of Dengue Virus Serotypes in the Dengue Outbreak of 2022 in Nepal
Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Kathmandu University
Abstract
ABSTRACT
Background
Dengue, a viral infection highly prevalent in tropical regions, exhibits local variations
in risks that are influenced by a combination of climatic, socioeconomic, and
environmental factors. It is caused by four distinct, yet closely related serotypes of
the dengue virus.
Objective
To identify the different serotypes of dengue virus responsible for the 2022 outbreak
in Nepal, where dengue has been prevalent since 2006 but with limited availability
of molecular information on the serotypes.
Method
Serum samples from suspected dengue patients visiting Dhulikhel Hospital were
analyzed using Dengue Rapid Test, for the presence of IgG/IgM antibodies or NS1 Ag.
The positive samples were stored at -80⁰C, and 89 samples were selected for further
analysis. RNA was extracted from those positive samples and RT-PCR was performed
to identify the serotypes present.
Result
A higher percentage of sero-positivity was observed in females(52%) compared
to males. Positive cases were distributed in 14 different districts, with the highest
percentage(58.4%) in Kavre. RT-PCR, of 53 out of 89 serologically positive samples,
by RT-PCR revealed that DENV1 was the predominant, followed by DEN3(24.5%) and
DENV2(16.9%). DENV4 was not detected in any of the samples. The average Ct-value
of all serotypes was 17.6, with DENV3 having the lowest Ct-value of 16.6, indicating
slightly higher viremia.
Conclusion
Our study, although limited in its coverage of Nepal, has provided molecular
information on the serotypes responsible for the 2022 dengue outbreak. The high
prevalence of DENV1 was observed, while prevalence of DENV3 was accompanied
by high viral load.
KEY WORDS
Dengue virus, Molecular, Serotypes, Nepal
Description
Katuwal N,1-3 Shrestha A,1-3 Ranjitkar U,1,3 Jakibanjar S,1,3 Madhup SK,4 Tamrakar D,1,3,5 Shrestha R1-3,6
1Center for Infectious Disease Research and Surveillance
2Molecular and Genome Sequencing Research Lab
3Research and Development Division
4Department of Microbiology
5Department of Community Medicine
6Department of Pharmacology
Dhulikhel Hospital, Kathmandu University Hospital
Kathmandu University School of Medical Sciences
Dhulikhel, Kavre, Nepal
Keywords
Dengue virus, Molecular, Serotypes, Nepal