Virus Research Center, Clinical Research Division, Sendai Medical Center, Miyagino-ku, Sendai, Miyagi, 983-8520, Japan; Department of Respiratory Medicine, The First People's Hospital of Yunnan Province, 650022, Kunming, PR China.
Virus Research Center, Clinical Research Division, Sendai Medical Center, Miyagino-ku, Sendai, Miyagi, 983-8520, Japan.
J Clin Virol. 2020 Dec;133:104662. doi: 10.1016/j.jcv.2020.104662. Epub 2020 Oct 18.
Influenza C virus causes mild respiratory diseases in humans. Previous studies suggested that the predominant hemagglutinin-esterase gene lineage circulating in children might be selected among the adult population, yet the prevalence of influenza C virus in adults has not been described.
To evaluate the frequency of influenza C virus infection in adults.
We performed hemagglutination inhibition assays of serum samples collected at periodic occupational medical checkups from employees of a hospital. A total of 679 serum samples were collected from 57 subjects who participated in biannual medical checkups between 2011 and 2016 as part of a longitudinal series. Titers of antibodies against the C/Kanagawa and C/Sao Paulo lineage viruses were detected.
Ten serum sample pairs from among the 57 subjects showed at least a four-fold increase in influenza C antibody titers. Samples from three subjects exhibited antibody titer increases for both the C/Kanagawa and C/Sao Paulo lineages, four subjects showed an increased titer against the C/Sao Paulo lineage, and three subjects showed an increased titer against the C/Kanagawa lineage. Half of the antibody titer increases for the C/Kanagawa lineage were detected in May 2014, while the increases for the C/Sao Paulo lineage were detected from 2011 to 2016.
The 5-year influenza C virus infection rate was estimated at 17.5 %. There were antibodies that cross-reacted with the C/Sao Paulo and C/Kanagawa lineages. The results suggest that C/Sao Paulo was the main lineage in the adult population of this area, with cocirculation of the C/Kanagawa lineage.
C 型流感病毒可引起人类轻度呼吸道疾病。既往研究提示，在儿童中流行的主要血凝素-神经氨酸酶基因谱系可能是在成年人群中选择的，但尚未描述成年人中 C 型流感病毒的流行情况。
评估成人中 C 型流感病毒感染的频率。
我们对医院定期职业体检的员工血清样本进行血凝抑制检测。2011 年至 2016 年，作为一项纵向研究的一部分，共有 57 名参与者参加了每两年一次的体检，共采集了 679 份血清样本。检测了针对 C/Kanagawa 和 C/Sao Paulo 谱系病毒的抗体滴度。
在 57 名参与者的 10 对血清样本中，至少有 4 倍的 C 型流感病毒抗体滴度升高。有 3 名参与者的血清样本同时出现了对 C/Kanagawa 和 C/Sao Paulo 谱系的抗体滴度升高，4 名参与者的 C/Sao Paulo 谱系抗体滴度升高，3 名参与者的 C/Kanagawa 谱系抗体滴度升高。C/Kanagawa 谱系的半数抗体滴度升高发生在 2014 年 5 月，而 C/Sao Paulo 谱系的抗体滴度升高则发生在 2011 年至 2016 年期间。
5 年的 C 型流感病毒感染率估计为 17.5%。存在与 C/Sao Paulo 和 C/Kanagawa 谱系交叉反应的抗体。结果表明，C/Sao Paulo 是该地区成年人群中的主要谱系，同时存在 C/Kanagawa 谱系的共同流行。
