Infectious Disease Risk Assessment for the Tokyo Olympic andParalympic Games(Updated Version)
Note: This document describes the infectious disease risk assessment and preparedness
to be considered for the Tokyo Olympic and Paralympic Games.
June 23, 2021
National Institute of Infectious Diseases
Center for Emergency Preparedness and Response,
Center for Field Epidemic Intelligence,
Research and Professional Development,
Center for Surveillance, Immunization, and Epidemiologic Research
BackgroundDue to the global pandemic of coronavirus disease 2019 (COVID-19), the Tokyo
Olympic and Paralympic Games ("the Games") were postponed from 2020 to 2021. The
Olympics were rescheduled to the period from Friday, July 23 to Sunday, August 8, 2021
and the Paralympics to the period from Tuesday, August 24 to Sunday, September 5,
2021. As the Games are to be held during the continued global COVID-19 pandemic, it
was decided not to allow foreign spectators to come to Japan. Athletes from more than
200 countries and regions are expected to participate in the Games, and several tens of
thousands of people from abroad, including competition staff, media staff, and sponsors,
are expected to enter the country for the Games. The events are to be held in Tokyo, thehost city, as well as eight other prefectures. The athletes' villages (including branch
villages) are located in three prefectures. All 47 prefectures have host towns and training
camp grounds.
In 2017 and 2018, each related municipality conducted a risk assessment for the
Games and implemented preparedness measures, such as strengthening surveillance andsecuring medical capacity as needed for each municipality. Since the outbreak of COVID19, infectious disease trends have been changing within and outside Japan due to theimplementation of comprehensive infection prevention measures and movement
restrictions. While it is essential to take countermeasures against COVID-19 for the
Games, it is also important to reassess the risks of other infectious diseases and to takeaction to prevent and mitigate their impact if they occur.
This document is an update of the risk assessment of infectious diseases for the Gamesin Japan, based on the risk assessment of infectious diseases for the Tokyo Olympic andParalympic Games (hereinafter referred to as the “Infectious Disease Risk Assessment
for the 2020 Tokyo Olympic and Paralympic Games” (1)) conducted in October 2017.
In this document, parties with their personal information, affiliated organizations, etc.

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registered with the Tokyo Organising Committee of the Olympic and Paralympic Games(“Committee”) are referred to as “registered personnel (accredited personnel).” Other
related persons who are not required to register with the Committee, such as freelance
reporters, host town officials, city volunteers registered with municipalities, andspectators living in Japan, are referred to as “non-registered personnel (non-accredited
personnel).” “Community” in this document refers to persons in areas other than special
controlled areas (“designated areas”) over which the Committee has jurisdiction or withwhich it has a partnership.
Risk assessment and recommended risk control measures
Especially for infectious diseases spread by human-to-human transmission such as
COVID-19, it is important to implement strict control measures, because the Games
involve several hundred to several thousand personnel (both registered and nonregistered) grouped together in sports venues and other facilities, resulting in a risk ofoutbreak. Games personnel are required to thoroughly follow risk control measures andto act in compliance with the Playbooks at all times.
The activities of registered personnel during the 14 days after entry into Japan are, in
general, restricted to the designated areas. However, contact between registered and nonregistered personnel, and between Games personnel (both registered and non-registered)and the community, may occur after moving out of the designated areas. Risk
management based on the possibility of contact with others is important to prevent the
spread of infection from Games personnel to the community. In general, registeredpersonnel from overseas should be restricted to the designated areas during their stay inJapan. In addition, a strict management system is desirable, including the avoidance ofcontact with the community for at least 14 days after moving out of the designated areas.
In particular, it is necessary to establish an appropriate management system that prevents
foreign media staff who may conduct activities over a wide geographical range, as wellas domestic volunteers who may come into contact with registered personnel fromoverseas, from developing infections and transmitting them to the community.
Although the period of stay is limited after moving out of the designated areas, athletes
and other Games personnel may remain in Japan after the end of the Games and directly
visit medical institutions in the community if they develop infectious or other diseases.
During the period from one month before to one month after the Games, athletes andother Games personnel are expected to visit or stay in Japan; the Committee, medical
institutions, and municipal governments should recognize this and be prepared to detect
and respond to infectious disease outbreaks among Games personnel (both registered andnon-registered). In addition, since the Games are an event that attracts wide international
attention, the occurrence of cases/outbreaks among Games personnel, as well as exportof infections from Japan by these personnel, need to be given attention and information
sharing mechanisms should be ensured under the International Health Regulations (IHR)
before the Games begin, with consideration for reputational risks.

2For COVID-19, the risk of spread from imported cases to the local community is
considered to be low if risk management measures are thoroughly implemented andmonitored during the Games. However, if these measures are not properly followed forGames personnel in the designated areas, there is an increased risk of causing spread in
the community after moving out of the designated areas. Therefore, risk management
measures should be thoroughly implemented for athletes and other Games personnel,
including foreign reporters and volunteers. Efforts to reduce human movement, including
strong recommendations for remote work, have been underway in the community.
However, when Games personnel travel domestically during the Games, occasions will
increase for people to gather for cheering, at Games venues, training camps, etc., andthere will be an increase in movement of people within and between jurisdictions, causing
an increased risk of spreading infection within Japan.
Regarding infections other than COVID-19, those that require special attention due toincreased risk of domestic transmission are listed by category and their respective risk
assessment is summarized as indicated in the table below, as per the “Infectious Disease
Risk Assessment for the 2020 Tokyo Olympic and Paralympic Games” (1) conducted in2017. Selected major infectious diseases are those that require attention due to theirassociation with certain risks, including an increased risk of importation, a significant riskof spread among Games personnel and in the community, the potential risk of a largescale epidemic, and high disease severity. Refer to “Infectious Disease Risk Assessment
for the 2020 Tokyo Olympic and Paralympic Games” (1) for the listing methodology.
Infectious diseases listed in the table are those that require caution when implementing
countermeasures, although the rate of risk has been changed for certain diseases* since2017 or other time points before the COVID-19 pandemic, as a result of various measurestaken against COVID-19 in Japan and overseas. In addition to COVID-19, measles,
invasive meningococcal disease, Middle East respiratory syndrome, andenterohemorrhagic Escherichia coli infection require special attention, just as in theprevious risk assessment.
* The risk of spread of respiratory infections such as influenza is lower than that before
the COVID-19 pandemic as a result of measures taken against COVID-19 in Japan andoverseas. The risk of importation of infectious diseases such as dengue fever is also lower
due to a decrease in the number of travelers based on the travel restrictions in many
countries. Conversely, the risks of food-borne diseases caused by enterohemorrhagic
Escherichia coli, norovirus, etc., and sexually transmitted infections have not decreased
compared to before the COVID-19 pandemic.

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Table 1. Infectious diseases thatcountermeasures and risk assessment

requirecautionwhen

implementing

Risk assessment
Vaccinepreventablediseases(VPD)

Measles

Although the epidemic status is low in Japan and overseas,
measles continues to occur in certain overseas areas.
There is a risk of importation and spread to local
populations with a low vaccination rate, which will resultin a high burden on medical institutions, health centers,
etc. in the event of a large outbreak. There is concern overa slight decrease in the vaccination rate in Japan during
the COVID-19 pandemic. There may be gaps in the levelof risk awareness among personnel from countries freefrom the disease.

Rubella

Although the epidemic status is low in Japan and overseas,
there are concerns about imported cases causing infection
clusters in populations with a low vaccination rate,
resulting in the development of congenital rubella
syndrome in infected pregnant women. There may be gaps
in the level of risk awareness among personnel fromcountries free from the disease.

Invasivemeningococcal
diseaseOverseas epidemiological information has not been
sufficiently obtained during the period of the COVID-19
pandemic, though the domestic epidemic status is low.
Although the probability of occurrence may be lower than
before the COVID-19 pandemic, the impact and theburden for the response would be high, particularly if thecases occur among Games personnel.

Influenza

Although the epidemic status is low in Japan and overseas,
epidemics have been observed in certain tropical andsubtropical regions. During the Games, seasonal increaseis expected in the southern hemisphere. There is apossibility of spread from imported cases among Games
personnel.

Pertussis

The epidemic status in Japan is low. There is a possibilityof spread from imported cases among Games personnel.

Middle East
respiratory
syndrome

The current epidemic status in the Middle East is low, butthere is a risk of importation by personnel visiting Japan
from the regions in which the cases have been reported. In
the event of occurrence among Games personnel, theburden of contact tracing and risk communication would
be high. There is concern about relatively lower awarenessof this disease due to the COVID-19 pandemic.

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Food-borne
infections†

OthersMosquito-borne
infections(dengue fever,chikungunya fever,
Zika virus infection)

Although there are overseas regions with a high epidemic
status, the numbers of imported cases have markedly
decreased due to the decreased number of travelers. Thereis a risk of importation from endemic areas. The burden of
vector control measures would be high in the case ofcluster infection in an athletes’ village or training camp.

Enterohemorrhagic
Escherichia coli
infection

In Japan, reported cases increase from June to September
every year. Caution must be taken to avoid the spread by
food-borne transmission among Games personnel.

Shigellosis

There are risks of importation and spread by food-borne
transmission among Games personnel.

Hepatitis A

There are risks of importation and spread by food-borne
transmission among Games personnel. Even if infection
spreads in association with the Games, the disease may be
detected after the end of the Games due to its relatively
long incubation period.

Hepatitis E

There are risks of importation and spread by food-borne
transmission among Games personnel. Even if infection
spreads in association with the Games, the disease may be
detected after the end of the Games due to its relatively
long incubation period.

Infectious
gastroenteritis(including norovirus
infection,
salmonellosis, andcampylobacter
infection)

Although incidence is expected to be low during theperiod of the Games according to seasonality, attention
should be paid because sporadic cases of norovirus
infection have been reported during previous Summer
Games and cluster infections have been reported among
personnel during previous Winter Games.

Tuberculosis

There are risks of importation and spread of infection
among Games personnel. Even if infection spreads inassociation with the Games, it may be detected after the
Games.

Syphilis

There is concern that infection may spread to Games
personnel through sexual intercourse. Even if infection
spreads in association with the Games, it is likely to be
detected after the Games.

HIV/AIDS

There are risks of importation and spread of infection
among Games personnel. Even if infection spreads inassociation with the Games, it is likely to be detected after
the Games.
†
Transmission pathways other than food-borne transmission are also possible.

5Infection prevention and control measures to be strengthened or added for theGames
First, regarding COVID-19 infection, it is necessary that the Committee ensures theimplementation of risk control measures, including vaccination among Games
personnel prior to the Games, and that the rules and regulations for infection
prevention and control are strictly followed by Games personnel. In addition, it isextremely important that the national and municipal governments prepare forincreased occurrence of COVID-19 infections, including strengthening of systems tosecure necessary human resources for immediate response to possible scenarios. For
infectious diseases other than COVID-19, it is necessary to be aware of theirepidemic statuses overseas, re-check the vaccination rate for local vaccinepreventable diseases and promote vaccination, and make medical institutions awareof the need to differentiate between COVID-19 and other important diseases, withreference to the results of the risk assessments performed by each municipal
government before the postponement of the Games. In addition, in order to enable
the early detection of serious infectious illness of unknown causes, it is desirable thatthe municipalities make local medical institutions aware of necessity of reporting to
the Undiagnosed Serious Infectious Illness Surveillance (2) revised in 2019. Infection
prevention and control measures to be strengthened or added by residents and thenational and municipal governments for the Games are listed below.
 Thorough implementation of measures to prevent the spread of infection among
spectators at sports venues, etc.
- Persons with symptoms and signs (based on body temperature check) should refrainfrom attending the Games- Ensure the proper use of facemasks (combined with measures against heat stroke,
avoidance of yelling, etc.)- Avoid the three Cs (close-contact settings, crowded places, and closed spaces) andmaintain physical distance- Ensure hand washing and sanitization- Ensure ventilation as much as possible- When making decisions about going out, traveling across jurisdictions, or participatingin activities where people may congregate, carefully consider the local COVID-19
situation and medical capacity level, based on official information such as those
provided by local government authorities- Ensure recommended doses of COVID-19 vaccinations (promotion of reliablevaccination in the target population and prompt expansion of the target population as
appropriate) Enhanced surveillance of infectious diseases and information sharing among6

municipal governments
Since there is a possibility of cluster infection across jurisdictions, it is necessary
to establish a system for reporting and information sharing as specified below,
and to secure human resources.
- Mandatory reporting of confirmed cases of infection (including suspected cases forcertain diseases) among Games personnel by medical institutions (enter the key word“Games personnel”); utilization of the Health Center Real-time Information-sharing
System (HER-SYS) for COVID-19 and the National Epidemiological Surveillance ofInfectious Diseases (NESID) system for other infections- Cooperation with quarantine stations for the detection and response to cases ofinfectious diseases among Games personnel- Mandatory reporting of severe infections of unknown causes to the Undiagnosed
Serious Infectious Illness surveillance system (including information on Games
personnel)- Thorough checking and verifying of information on Games personnel by public healthcenters, local health institutes, the National Institute of Infectious Diseases, and theMinistry of Health, Labour and Welfare, for the registration of confirmed cases ofinfection (including suspected cases for certain diseases)- Routine information sharing through daily reports on the incidence of infectious
diseases in Japan and overseas and risk assessments related to the Games from thenational government to the municipalities and the Committee- Timely information sharing among the Committee, related municipal governments, andnational government regarding performance of testing, including the number of tests forand incidence of infectious diseases among Games personnel (by sharing respective
daily reports, etc.)- Timely sharing of the findings of epidemiological investigations conducted bymunicipal governments with the national government and the Committee in the eventof infection among Games personnel
 Testing system- Establishment of a system for testing, reporting, and confirmation that can promptly
present the local infectious diseases epidemiologic situation, especially in areas withsports venues and training camp grounds for athletes Strengthening of response to outbreaks and securing of medical services andcapacity- Establishment of a response system assuming for outbreaks of infectious diseases,
including cluster infections of disease and local outbreaks of COVID-19 associated with
the Games, strengthening of the cooperative response system among organizations (thenational government, municipal governments, and the Committee), and securing offacilities for hospitalization and recuperation

7 Communication- Dissemination of consistent information, both domestically and internationally, atroutine intervals (including reports of zero cases/clusters) and in the event ofcases/clusters among Games personnel- Timely communication with international organizations and IHR National Focal Points
in relevant countries through an IHR mechanism, in the notifiable event of cases/clusters
associated with the Games that may affect other countries- Strengthening of information collection systems in other countries for cases/clusters
detected overseas in association with the Games After-Action Review for the Games- Because the Games are to be held during the COVID-19 pandemic, it is necessary to
conduct an after-action review to evaluate the domestic and international impact after
the Games
References
1) Office Memorandum from the Tuberculosis and Infectious Diseases Control Division,
Health Service Bureau, Ministry of Health, Labour and Welfare. Dated October 5,
2017. “Risk Assessment of Infections for the 2020 Tokyo Olympic and Paralympic
Games
Proceduresfor
Municipalities”.
(inJapanese)https://www.mhlw.go.jp/file/05-Shingikai-10601000-DaijinkanboukouseikagakukaKouseikagakuka/sanko10.pdf
2) Ministry of Health, Labour and Welfare. Revised on February 21, 2019.
“Undiagnosed Serious Infectious Illness Specified in the MHLW Ordinance set forthin Article 14, Paragraph 1 of the Act on the Prevention of Infectious Diseases andMedical Care for Patients with Infectious Diseases (the Infectious Diseases ControlLaw)”.
(inJapanese)https://www.mhlw.go.jp/bunya/kenkou/kekkakukansenshou11/01-07-01.html

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