Molecular epidemiology and immunology of sapovirus infection in infants and children

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10455
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Nihon University
• Principal Investigator: OKITSU Shoko 日本大学, 医学部, 客員研究員 (10082215)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ウイルス性胃腸炎 / サポウイルス / 分子疫学 / 小児 / 感染免疫

Outline of Final Research Achievements

A variety of viruses are known to cause acute gastroenteritis (AGE) in infants and children. In Japan, rotavirus vaccination has been implemented since 2011, and then numbers of rotavirus-induced AGE gradually decreased. Hereafter, the sapovirus-induced AGE seems to increase, therefore, molecular epidemiology and characterization of sapovirus (SaV) genotypes were studied. The prevalence of SaV infection has changed year by year, and was average 5.2%. The predominant genotype was GI.1 and other seven genotypes were detected. In the infected children, genotype-specific immunity was elicited, however, age-dependent antibody titers in the sera were not observed in the healthy subjects using the virus-like particles of SaV. The infants were given passive immunity against SaV from their mothers.
Numbers of collected stool samples in the AGE children and of SaV-positive samples decreased during the COVID-19 epidemic, and the numbers of them increased in the following year.

Free Research Field

公衆衛生学

Academic Significance and Societal Importance of the Research Achievements

小児の急性胃腸炎は日本では死亡者数は少ないものの誰でも罹患する疾患で乳幼児やその家庭における負担となっている。その原因ウイルスは多く、その一つであるロタウイルスに対するワクチンは2020年に日本で定期接種となった。そこで今後どのようなウイルスが流行するか知ることは、感染防御対策を探るために重要である。この研究では原因ウイルスの一つであるサポウイルスを対象として流行疫学とその特徴を調べ、一方で遺伝子型に対する免疫を調べた。ロタウイルスワクチンの影響と新型コロナウイルス感染症流行の影響を考えて継続的な調査が必要である。