1912. Epidemiologic comparison of laboratory-confirmed influenza virus B Yamagata and Victoria lineage infections during the 2014-2015 influenza season
Session: Poster Abstract Session: Vaccines: Influenza
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • IDSA IISP B-lineage analysis - Poster 092515.pdf (228.6 kB)
  • Background:   Two distinct genetic lineages of influenza B viruses, Yamagata and Victoria, co-circulate each year in the United States. Although both lineages have been included in quadrivalent influenza vaccine since 2013, few studies have examined lineage-specific epidemiologic characteristics of patients with influenza. 

    Methods:   From August 2014 to May 2015, 34 outpatient providers representing 6 of 8 health departments participating in the Influenza Incidence Surveillance Project (IISP) collected respiratory specimens and clinical data from the first 10 patients presenting each week with acute respiratory illness. Specimens were tested for influenza subtype and lineage using RT-PCR.  We examined Yamagata and Victoria lineage virus circulation patterns and compared characteristics reported during the 2014-15 influenza season.

    Results:   Influenza was detected in 793 (27%) of 2974 specimens collected, including 591 (75%) A viruses and 202 (26%) B viruses (Figure 1A).  The genetic lineage was determined for 197 (98%) B virus detections; 154 (78%) were Yamagata lineage.  From September to December 2014, both B lineages were sporadically detected in approximately equal proportions; in 2015 months, 82% of B detections were Yamagata lineage compared with 17% Victoria lineage (p<0.01 Figure 1B).  Patients with Victoria lineage were significantly younger than those with Yamagata (median age 13 years vs. 33.5 years, respectively p<0.01).  Among children aged <5 years, 56% of influenza B was Victoria lineage compared with 18% among patients aged >5 (p<0.01).  Patients with Yamagata virus were more likely to report sore throat compared with Victoria (57% vs. 38%, respectively p<0.01), but other symptoms did not differ by lineage.    

    Conclusion:   Influenza B Yamagata and Victoria lineage viruses co-circulated during the 2014-15 season with Yamagata predominance apparent only after December 2014. Victoria lineage viruses were much more common among children aged <5 years, throughout the season.  High circulation of Victoria lineage viruses, particularly among young children, emphasizes the potential importance of quadrivalent influenza vaccines, which contain both lineages.

    Ashley Fowlkes, MPH1, Andrea Steffens, MPH1, Jonathan Temte, MD, PhD2, Erik Reisdorf, MPH3, Heather Rubino, PhD4, Karen Martin, MPH5, David Boxrud, MS6, Jason Wotton, MA5, Lesley Brannan, MPH7, Johnathan Ledbetter, MPH7, Christine Selzer, MPH8, Nicole Green, PhD, D(ABMM)9, John Diaz-Decaro, MS9, Steve Di Lonardo, MS10, Jie Fu, PhD11, Stephen Lindstrom, PhD12 and Lea Heberlein-Larson, MPH, SM(ASCP)CM13, (1)Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, (2)Family Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, (3)Communicable Disease Division, Wisconsin State Laboratory of Hygiene, Madison, WI, (4)Florida Department of Health, Tallahassee, FL, (5)Minnesota Department of Health, St. Paul, MN, (6)Public Health Laboratory, Minnesota Department of Health, St. Paul, MN, (7)Texas Department of State Health Services, Austin, TX, (8)Los Angeles County Department of Public Health, Los Angeles, CA, (9)Los Angeles County Department of Public Health, Downey, CA, (10)New York City Department of Health and Mental Hygiene, Long Island City, NY, (11)Bureau of Public Health Laboratory, New York City Department of Health and Mental Hygiene, New York, NY, (12)Centers for Disease Control and Prevention (CDC), Atlanta, GA, (13)Florida Department of Health, Tampa, FL

    Disclosures:

    A. Fowlkes, None

    A. Steffens, None

    J. Temte, None

    E. Reisdorf, None

    H. Rubino, None

    K. Martin, None

    D. Boxrud, None

    J. Wotton, None

    L. Brannan, None

    J. Ledbetter, None

    C. Selzer, None

    N. Green, None

    J. Diaz-Decaro, None

    S. Di Lonardo, None

    J. Fu, None

    S. Lindstrom, None

    L. Heberlein-Larson, None

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