Epidemics of two Victoria and Yamagata influenza B lineages in Yamagata, Japan

Abstract

We attempted to predict epidemics of influenza B, focusing on B/Victoria/2/87-like (V) and B/Yamagata/16/88-like (Y) lineages, in Yamagata, Japan. We collected 9624 nasopharyngeal swabs for virus isolation from patients with respiratory infections between 1996 and 2003 and 237 sera for seroepidemiological analysis by haemagglutination-inhibition test in 2001. We isolated 424 V-lineage and 246 Y-lineage viruses during the study period. Three herald viruses in the 2000--2001 season enabled us to predict a V-lineage epidemic in the following season. However, another V-lineage epidemic occurred in the 2002--2003 season, although we caught four herald Y-lineage viruses, whose antigenic drift was suggested by seroepidemiological study, at the end of the previous season. Since the epidemiology of the two influenza B lineages remains unclear, a careful watch should be kept on these lineages in order to provide effective public-health strategies against future epidemics.

Pathogenesis and Transmission of Swine-Origin 2009 A(H1N1) Influenza Virus in Ferrets

“…The shedding and transmission data suggested that the 2009 A(H1N1) is sufficiently fit to compete with the seasonal A(H1N1) virus. Because serological cross-reactivity between 2009 A(H1N1) and seasonal H1N1 viruses was found to be negligible (5), and different antigenic variants of influenza B viruses have coexisted for extended periods of time (22), the 2009 A(H1N1) influenza virus should be considered capable of continued cocirculation in the human population with the existing seasonal influenza viruses.…”

Longitudinal Epidemiology of Viral Infectious Diseases Combining Virus Isolation, Antigenic Analysis, and Phylogenetic Analysis as Well as Seroepidemiology in Yamagata, Japan, between 1999 and 2018

“…We published our first paper related to our microplate method focusing on enterovirus isolation in 2003 (18). We then published 3 papers related to Echo13, Ad7, and Flu B using virus isolation and serological techniques such as the NT test and HI test (31)(32)(33). These papers on Echo13 and Ad7 were our first studies related to emerging and re-emerging viral diseases, which later became an important theme in our research.…”