Research Objective and Method

Research Objective

Since December 2019, patients with the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported, among residents of Wuhan, Hubei Province, China. More than 10 million cases of infection and more than 550,000 deaths have been reported worldwide within six months after the first patient was discovered. As a Public Health Emergency of International Concern, this infectious disease calls for immediate and sustainable measures. Japan has resumed its economic and social activities around the time when its first outbreak between April and May 2020 had passed.
In the process, clusters at so-called "nightlife businesses" were reported nationwide. Knowing the scale of spread within these clusters and the risk of infection among individual employees is important in order to achieve the best possible balance between pursuing economic and social activities, and curtailing SARS-CoV-2 outbreaks.
The objective of this study was to understand the current situation in populations that are likely to be at high risk of infection, by combining laboratory data (through PCR and antibody testing) with epidemiological information from interviews, questionnaires, and observations at nightlife businesses (host clubs).

Infectious Agents Surveillance Report (IASR)
Published on December 28, 2020
See below for excerpts and details (in Japanese)

Research Method

●Interviews with representatives of host clubs
We interviewed the representatives of each clubs about their infection prevention measures and the status of business operations prepandemic period and during pandemic (before and after a positive case was found).

●Site visits to the clubs and assessments of current infection prevention measures
We visited the establishments to directly observed their infection prevention measures, and also offered feedback and advice on how to improve.

●Questionnaire surveys to employees (mainly male hosts)
We conducted a self-administered questionnaire on the presence of any symptoms in individual employees, the status of their past COVID-19 tests, daily life, and their prevention measures against infection.

●PCR and antibody tests
We conducted PCR and antibody tests on individual employees to assess the current and past infection status.

Note: Questionnaire surveys and tests were conducted three to four times every other month, with it was considered to be important to assess changes in awareness and status of infection in the long run.