tetano
Editor, Senior Moderator
Euro Surveill
. 2020 Oct;25(41).
doi: 10.2807/1560-7917.ES.2020.25.41.1900652.
Detection and discrimination of influenza B Victoria lineage deletion variant viruses by real-time RT-PCR
Bo Shu[SUP] 1 [/SUP], Marie K Kirby[SUP] 2 1 [/SUP], Christine Warnes[SUP] 1 [/SUP], Wendy M Sessions[SUP] 1 [/SUP], William G Davis[SUP] 2 1 [/SUP], Ji Liu[SUP] 3 1 [/SUP], Malania M Wilson[SUP] 1 [/SUP], Stephen Lindstrom[SUP] 4 [/SUP], David E Wentworth[SUP] 1 [/SUP], John R Barnes[SUP] 1 [/SUP]
Affiliations
Abstract
BackgroundDuring the 2016/17 influenza season, influenza B/VIC lineage variant viruses emerged with two (K[SUB]162[/SUB]N[SUB]163[/SUB]) or three (K[SUB]162[/SUB]N[SUB]163[/SUB]D[SUB]164[/SUB]) amino acid (aa) deletions in the haemagglutinin (HA) protein. There are currently five antigenically distinct HA proteins expressed by co-circulating influenza B viruses: B/YAM, B/VIC V1A (no deletion), B/VIC V1A-2DEL (2 aa deletion) and two antigenically distinguishable groups of B/VIC V1A-3DEL (3 aa deletion). The prevalence of these viruses differs across geographical regions, making it critical to have a sensitive, rapid diagnostic assay that detects and distinguishes these influenza B variant viruses during surveillance.AimOur objective was to develop a real-time RT-PCR (rRT-PCR) assay for detection and discrimination of influenza B/VIC lineage variant viruses.MethodsWe designed a diagnostic assay with one pair of conserved primers and three probes specific to each genetic group. We used propagated influenza B/VIC variant viruses and clinical specimens to assess assay performance.ResultsThis rRT-PCR assay detects and distinguishes the influenza B/VIC V1A, B/VIC V1A-2DEL, and B/VIC V1A-3DEL variant viruses, with no cross-reactivity. This assay can be run as a multiplex reaction, allowing for increased testing efficiency and reduced cost.ConclusionCoupling this assay with the Centers for Disease Control and Prevention's Human Influenza Virus Real-Time RT-PCR Diagnostic Panel Influenza B Lineage Genotyping Kit results in rapid detection and characterisation of circulating influenza B viruses. Detailed surveillance information on these distinct influenza B variant viruses will provide insight into their prevalence and geographical distribution and could aid in vaccine recommendations.
Keywords: B/Victoria lineage; deletion variant virus; real-time RT-PCR.
. 2020 Oct;25(41).
doi: 10.2807/1560-7917.ES.2020.25.41.1900652.
Detection and discrimination of influenza B Victoria lineage deletion variant viruses by real-time RT-PCR
Bo Shu[SUP] 1 [/SUP], Marie K Kirby[SUP] 2 1 [/SUP], Christine Warnes[SUP] 1 [/SUP], Wendy M Sessions[SUP] 1 [/SUP], William G Davis[SUP] 2 1 [/SUP], Ji Liu[SUP] 3 1 [/SUP], Malania M Wilson[SUP] 1 [/SUP], Stephen Lindstrom[SUP] 4 [/SUP], David E Wentworth[SUP] 1 [/SUP], John R Barnes[SUP] 1 [/SUP]
Affiliations
- PMID: 33063654
- DOI: 10.2807/1560-7917.ES.2020.25.41.1900652
Abstract
BackgroundDuring the 2016/17 influenza season, influenza B/VIC lineage variant viruses emerged with two (K[SUB]162[/SUB]N[SUB]163[/SUB]) or three (K[SUB]162[/SUB]N[SUB]163[/SUB]D[SUB]164[/SUB]) amino acid (aa) deletions in the haemagglutinin (HA) protein. There are currently five antigenically distinct HA proteins expressed by co-circulating influenza B viruses: B/YAM, B/VIC V1A (no deletion), B/VIC V1A-2DEL (2 aa deletion) and two antigenically distinguishable groups of B/VIC V1A-3DEL (3 aa deletion). The prevalence of these viruses differs across geographical regions, making it critical to have a sensitive, rapid diagnostic assay that detects and distinguishes these influenza B variant viruses during surveillance.AimOur objective was to develop a real-time RT-PCR (rRT-PCR) assay for detection and discrimination of influenza B/VIC lineage variant viruses.MethodsWe designed a diagnostic assay with one pair of conserved primers and three probes specific to each genetic group. We used propagated influenza B/VIC variant viruses and clinical specimens to assess assay performance.ResultsThis rRT-PCR assay detects and distinguishes the influenza B/VIC V1A, B/VIC V1A-2DEL, and B/VIC V1A-3DEL variant viruses, with no cross-reactivity. This assay can be run as a multiplex reaction, allowing for increased testing efficiency and reduced cost.ConclusionCoupling this assay with the Centers for Disease Control and Prevention's Human Influenza Virus Real-Time RT-PCR Diagnostic Panel Influenza B Lineage Genotyping Kit results in rapid detection and characterisation of circulating influenza B viruses. Detailed surveillance information on these distinct influenza B variant viruses will provide insight into their prevalence and geographical distribution and could aid in vaccine recommendations.
Keywords: B/Victoria lineage; deletion variant virus; real-time RT-PCR.