Publication: Characterization of Seasonal Influenza Virus Type and Subtypes Isolated from Influenza Like Illness Cases of 2012
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Kathmandu University
Abstract
ABSTRACT
Background
Seasonal influenza is one of the increasing public health burdens in Nepal.
Objective
The objective of this study was to isolate and characterize the influenza virus type
and subtypes of Nepal.
Method
A total of 1536 throat swab specimens were collected from January to December
2012. Total ribonucleic acid was extracted using Qiagen viral nucleic acid extraction
kit and polymerase chain reaction assay was performed following the US; CDC Real-
time PCR protocol. Ten percent of positive specimens were inoculated onto Madin-
Darby Canine Kidney cells. Isolates were characterized by using reference ferret
antisera.
Result
Of the total specimens (n=1536), influenza virus type A was detected in 196 (22%)
cases; of which 194 (99%) were influenza A (H1N1) pdm09 and 2 (1 %) were influenza
A/H3 subtype. Influenza B was detected in 684 (76.9%) cases. Influenza A (H1N1)
pdm09, A/H3 and influenza B virus were antigenically similar to the recommended
influenza virus vaccine candidate of the year 2012. Although sporadic cases of
influenza were observed throughout the year, peak was observed during July to
November.
Conclusion
Similar to other tropical countries, A (H1N1) pdm09, A/H3 and influenza B viruses
were co-circulated in Nepal.
KEY WORDS
A (H1N1) Pdm09, influenza, real time PCR
Description
Upadhyay BP,1 Ghimire P,1 Tashiro M,2 Banjara MR1
1Department of Microbiology
National Public Health Laboratory
Tribhuvan University, Kathmandu, Nepal.
2National Institute of Infectious Disease
Tokyo, Japan
Keywords
A (H1N1) Pdm09, influenza, real time PCR