Serotype of Dengue Virus Causing Dengue Outbreak in Kathmandu

Abstract

Background: The most dengue cases ever recorded in Nepal were reported in 2019, the greatest number to date. The incidence of dengue infections in Kathmandu is examined from an epidemiological standpoint in this paper. Since its initial introduction in 2004, dengue cases—including some significant outbreaks—have been consistently reported in Nepal. The purpose of this study was to identify and characterise the dengue virus (DENV) at the molecular level in dengue patients.
Methods: This study had 579 patients in all. Dengue patients who visited the National Public Health Laboratory provided demographic, clinical, and laboratory data. RT-PCR analysis was performed after immunochromatographic detection assays to confirm dengue infection.
Results: By immunochromatographic screening, 234 (40.41%) of the 579 patients tested positive for the Dengue virus. Of them, 185 (79.05%) samples tested positive for the NS1 antigen, 36 (15.38%) tested positive for IgM, and 1 (0.42%) tested positive for IgG. Remarkably, 345 samples tested negative for dengue virus, while 12 (5.12%) tested positive for both NS1 and IgM. 93 of the 185 NS1-positive samples underwent real-time PCR characterisation. We discovered that the most common serotype causing the 2019 outbreak was DENV-2, 90 (96.77%). Interestingly, co-infection with DENV 1 and DENV 3 was reported in one patient, while two samples tested negative for the Dengue virus.
Conclusions: According to our research, the main serotype responsible for the significant epidemic in Nepal in 2019 was DENV 2. Programs for disease control will benefit from this knowledge as it helps them comprehend molecular characterisation and its evolving trend.
Keywords: Dengue; DENV 2; Kathmandu; RT-PCR; serotype.