Follow-up evaluation for norovirus asymptomatic infection among healthy adults: A prospective matched cohort study

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K17358
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Tokyo Medical University (2021); St. Luke's International University (2018-2020)
• Principal Investigator: Kobayashi Daiki 東京医科大学, 医学部, 准教授 (30769617)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: ノロウイルス / 不顕性感染 / 前向きコホート

Outline of Final Research Achievements

This prospective age- and sex-matched cohort study included apparently healthy asymptomatic adults with a positive norovirus result and those with a negative result (ratio 1:3) during the 2016 to 2017 screening. The primary outcome was real-time reverse-transcription polymerase chain reaction-confirmed norovirus in stool specimens. Of 288 participants, 73 were positive for norovirus previously, while 215 were negative. After a median of 599 days between baseline screening and follow-up, 14 tested positive for norovirus (2.7% and 5.6% among positive- and negative-norovirus groups at baseline, respectively). Among previously norovirus-negative participants, being older, having elevated blood pressure and hemoglobin A1c level, and drinking Japanese sake at baseline were associated with positive results at follow-up. There may be higher risks of future asymptomatic norovirus infection in previously no-norovirus asymptomatic infection people with specific lifestyles or medical histories.

Free Research Field

疫学

Academic Significance and Societal Importance of the Research Achievements

本研究は、健常者を対象としたノロウイルス不顕性感染の前向き研究として、最大規模であり他に類を見ないものである。現在までの研究は横断研究が主であり、現在の感染を評価するのみであった。しかしながら本研究は前向き研究であり、過去に不顕性感染を起こしたものと、起こしていないものの双方の感染のリスクを評価した点でユニークである。