Influenza B Viruses in the Population of Province of Vojvodina during the 2012/2013 Season: Differentiation of B/Yamagata and B/Victoria Lineages by Real-time RT-PCR, Antigenic and Phylogenetic Characterization.
BACKGROUND
At present, two phylogenetically distinct influenza B virus lineages, B/Yamagata and B/ Victoria, co-circulate worldwide and can cause significant morbidity and mortality.


OBJECTIVE
The aim of this study was to determine the prevalences of two influenza B virus lineages in the population of Vojvodina and to identify their antigenic and phylogenetic properties.


METHODS
A total of 369 and 334 nasopharyngeal, or nasal/throat swab samples, collected during the 2012/2013 and 2013/2014 seasons, respectively, were tested using specific singleplex influenza A, influenza B, influenza B/Yamagata and influenza B/Victoria real-time reverse transcription polymerase chain reaction (RT-PCR) assays. Antigenic and genetic testing were done by hemagglutination inhibition assay and hemagglutinin and neuraminidase gene sequence analysis, respectively.


RESULTS
During the 2012/2013 season, influenza B viruses were present in 53.4% (101/189) of influenza positive samples.The B/Yamagata-like viruses (81.2%) significantly predominated over the B/Victoria-like viruses (18.8%). Comparing to B/Victoria-like positive patients, among B/Yamagata-like positive patients, children 5-14 years of age were significantly more represented (5.3% vs. 35.4%, respectively), as well as patients with mild form of illness (15.8% vs. 45.1%, respectively). The results of sequence analysis and antigenic testing showed that tested viruses were not closely related to B/Wisconsin/1/2010, the vaccine virus for 2012/2013. During the 2013/2014 season influenza B viruses were not detected.


CONCLUSIONS
The results of this study confirmed the health significance of influenza B viruses and indicated that B/Yamagata-like viruses were significantly more prevalent than B/Victoria lineage viruses, during the 2012/2013 season. They also showed a sub-optimal match between the tested viruses and the vaccine virus for season 2012/2013.
Jelena
J
Radovanov
Vesna
V
Milošević
Ivana Hrnjaković
IH
Cvjetković
Mioljub
M
Ristić
Milan
M
Djilas
Nataša
N
Nikolić
Aleksandra
A
Patić
Gordana
G
Kovačević
Aleksandra Jovanović
AJ
Galović
Tamaš
T
Petrović
Sandra Stefan
SS
Mikić
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D014644:Genetic Variation; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D009981:Influenza B virus / Q000145:classification* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008297:Male; D010802:Phylogeny; D011159:Population Surveillance; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012621:Seasons; D014739:Victoria; D015022:Yugoslavia / Q000453:epidemiology