Molecular epidemiologic and clinical characteristics of influenza B-associated complications among hospitalized patients during an outbreak in Taiwan.
OBJECTIVE
To study the resurgence of influenza B/Yam in Taiwan and summarize clinical findings of influenza B-associated complications among hospitalized patients, in particular the link between clinical and molecular epidemiologic characteristics.


METHODS
Clinical information and isolates were collected through the national surveillance system of the Taiwan Centers for Disease Control. Potential risk factors associated with severe illness were analyzed. Antigenic and genetic analysis of representative hemagglutinin (HA) nucleotide sequences was performed.


RESULTS
Of 326 patients admitted to the intensive care unit (ICU), 63.2% were aged ≤18 years or ≥65 years and 12.9% were adults aged 19-49 years. Most of the cases had underlying medical conditions before admission, and more fatal cases had chronic medical conditions than those who convalesced in the ICU. Results of the phylogenetic analysis showed that the majority of isolates from fatal cases in Taiwan were in group 2 (represented by B/Massachusetts/2/2012-like) rather than group 3, which was the predominant group of strains circulating in other Asian countries.


CONCLUSIONS
Our findings suggest a regional trend of influenza B viruses and showed that new phylogenetic lineages and antigenic variants emerging in neighboring countries were likely to be the progenitors of the epidemic strains in the following seasons.
Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kung-Yang St., Taipei 11513, Taiwan.
Shu-Chun
SC
Chiu
Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kung-Yang St., Taipei 11513, Taiwan; National Influenza Center, Centers for Disease Control, Taipei, Taiwan. Electronic address: jeffy320@cdc.gov.tw.
Jih-Hui
JH
Lin
Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kung-Yang St., Taipei 11513, Taiwan; National Influenza Center, Centers for Disease Control, Taipei, Taiwan.
Hsiao-Chi
HC
Wang
Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kung-Yang St., Taipei 11513, Taiwan; National Influenza Center, Centers for Disease Control, Taipei, Taiwan; School of Medical Laboratory Science and Biotechnology, Taipei Medical University, Taipei, Taiwan.
Ho-Sheng
HS
Wu
Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, No. 161, Kung-Yang St., Taipei 11513, Taiwan.
Hui-Wen
HW
Chang
Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
Yung-Cheng
YC
Lin
Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan; Department of Medical Research, Mackay Memorial Hospital, New Taipei City, Taiwan; Institute of Public Health, National Yang-Ming University, Taipei, Taiwan; Center for General Education, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
Hsin-Fu
HF
Liu
D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D014644:Genetic Variation; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D009981:Influenza B virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D012307:Risk Factors; D012621:Seasons; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
D000998:Antiviral Agents
Hospitalized patients; Influenza virus; Influenza-associated complications; Molecular epidemiology; Taiwan