Clinical and genetic characterization of severe influenza B-associated diseases during an outbreak in Taiwan.
BACKGROUND
Mismatches between circulating and vaccine strains of influenza virus had been observed in Taiwan. A comprehensive clinical and genetic analysis of influenza B viruses-associated important diseases was lacking.


OBJECTIVE
Clinical and phylogenetic analysis of influenza B viruses during an outbreak in Taiwan.


METHODS
Clinical manifestations of hospitalized, culture-confirmed patients were analyzed from July 2004 to June 2005. Partial genome sequence analysis of hemagglutinin (HA), neuraminidase (NA), and nonstructural (NS) genes were performed in 54 influenza B isolates during the study period, and nine srandomly chosen isolates during 2000 and 2003.


RESULTS
Three specific diseases were found in these patients, including 13 of encephalitis/encephalopathy, 28 of influenza-associated myositis (IAM), and one of acute respiratory distress syndrome (ARDS). Three phylogenetic groups were identified, including reassortant strains-group 1 (Victoria lineage of HA, Yamagata lineage of NA, clade A of NS), group 2 (Yamagata lineage of HA, Yamagata lineage of NA, clade A of NS), and group 3 (Yamagata lineage of HA, Yamagata lineage of NA, clade B of NS).


CONCLUSIONS
Severe influenza B-associated disease in children was not rare and might be fatal. We offered the evidence of co-circulation of the two HA lineages in the same outbreak.
Li
Wen-Chen
WC
Division of Pediatric Infectious Diseases, Chang Gung Children's Hospital, Taoyuan, Taiwan.
Shih
Shin-Ru
SR
Huang
Yhu-Chering
YC
Chen
Guang-Wu
GW
Chang
Shih-Cheng
SC
Hsiao
Mei-Jen
MJ
Tsao
Kuo-Chien
KC
Lin
Tzou-Yien
TY
D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004660:Encephalitis / Q000821:virology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006760:Hospitalization; D006801:Humans; D009981:Influenza B virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology / Q000821:virology*; D008297:Male; D017720:Molecular Epidemiology; D009220:Myositis / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012128:Respiratory Distress Syndrome / Q000821:virology; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology; D017361:Viral Nonstructural Proteins / Q000235:genetics
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins