Guide

on Active Epidemiological Investigation
for Public Health Nurses
In Response to COVID-19 in Japan

Regarding this guideThis guide is aimed to support Public Health Nurses (PHNs) who are working on active epidemiologicalinvestigation for COVID-19, especially for those who have urgently been placed as support.
Based on “Guidelines on conducting active epidemiological investigations for COVID-19 patients”
published by National Institute of Infectious Diseases, this document describes the rationale ofidentifying clusters through active epidemiological investigations as well as key points in conducting thesurvey. Please use this document along with the Guidelines.
”Guidelines on conducting active epidemiological investigations for COVID-19 patients” by National
Institute of Infectious Diseases
URL: https://www.niid.go.jp/niid/ ja/diseases/ka/corona-virus/2019-ncov/2484-idsc/9357-2019-ncov-02.html

Quick guide
P3: When the cluster response is positioned in active epidemiological investigation
P5: The steps and overview of active epidemiological investigation
P7: The key points and what to keep in mind when conducting hearings for confirmed cases
P12: How to handle persons who have been in close contact with infected individuals

Table of Contents

1. Position of cluster response in active epidemiological investigation		

3

2. Aim and steps of cluster response in active epidemiological investigation

5

3. Tips for interviews									

74. Handling of persons who had close contact with COVID-19 patients 		

12

Appendix 1: Mental care for persons who are involved in active epidemiologicalinvestigation 		

18

Appendix 2: Guideline for active epidemiological investigation for COVID-19 patients

19

Guide on Active Epidemiological Investigation for Public Health Nurses
In Response to COVID-19 in Japan
Authors
Etsuko Yoshikawa 		

Associate Professor, Japanese Red Cross College of Nursing, Faculty of Nursing

Maiko Fukumoto 		

PHN, Sony Life Insurance Co., Ltd.

Aya Iguchi		

Associate Professor, Japanese Red Cross College of Nursing, Faculty of Nursing

Akane Suzuki		Assistant Professor, International University of Health and Welfare Graduate School

Editorial supervisors
Wada Koji		International University of Health and Welfare, Faculty of Medicine

Tadatsugu Imamura

Japan International Cooperation Agency, Tokyo, Japan

Hitoshi Oshitani		

Tohoku University School of Medicine

Motoi Suzuki		National Institute of Infectious Diseases

Tomoya Saito		

National Institute of Public HealthAcknowledgements
In creating this document, we have received a lot of input from many PHNs.
We appreciate Mieko Kikuchi-Conbere for her translation this Japanese guide into English.
Contact
Etsuko Yoshikawa		

Associate Professor, Japanese Red Cross College of Nursing, Faculty of Nursing

			Email: e-yoshikawa@redcross.ac.jp
Wada Koji 		Professor, International University of Health and Welfare, Japan

			Email: kwada@iuhw.ac.jp

2

1. Positioning of cluster response in active epidemiological investigation

1.

Positioning of cluster response in active
epidemiological investigation

1-1. Characteristics of COVID-19
In Japan, We found that most COVID-19 patients (confirmed cases) are not generating secondary
cases (confirmed cases). We revealed that only about 10-20% of all patients are generating secondary
cases (confirmed cases). This means that most cases do not infect others, while some of the patients
infect many others.

Why is the disease spreading if most of the infected

多くの⼈が誰にも感染させていないのにindividuals are not infecting others?
なぜ流⾏が起こるのか？

infected person
感染者 11R0 = (0+0+0+0+10) ÷ 5 = 2

R0=（0+0+0+0+10)÷5=2

infected person
感染者 22Unless 1 person is infecting many while mostnotinfecting anyone多くの⼈は誰にも感染させない
誰にも感染させない
are not infecting anyone, the spread of theが⼀部に1⼈が多くの⼈に感染

infected person
感染者 33させていると考えないと流⾏がdisease CANNOT be explained.
起きている理由を説明できない

infected person
感染者 44

We defined "cluster" as group of >5 infected
リンクの追えない症例からつながった患者の集積のうち5⼈以
individuals that have been connected from上のものをクラスターとする

infected person
感染者 55
10⼈に感染infecting
10 people

cases without known epidemiological links.

1-2. Why is cluster response necessary?
Major community transmission occurs from chain of clusters or mega clusters, generating highvolume of secondary transmissions. As such, the key to prevent increase in transmissions is a prompt
identification of clusters of cases that have occurred within a region and appropriate response.

1-3. Under what conditions do clusters occur?

Closed spacewith poor
ventilation

Talking or
speaking inclose proximity

Cluster occurence risk ishigher where the 3 conditions
occur simultaneously

3C Conditions(closed, crowded, close contact)

Crowds ofpeople withinarms reach□

Loud voices□

Singing□

Activities that increase breathing□

Close contact with multiple people

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan

3

•
•
•

Chances of forming clusters does not correlate with severity. In fact, the asymptomatic cases arelikely to be more active and increases the likelihood of forming clusters.
Majority of people identified in clusters had only mild symptoms such as sore throat and slight fever
It is possible that broader transmission outside of the expected distance (1-2m) happens in closed
environments.

Please conduct interviews with understanding of the virus’ nature that anyone can be infectedwithout knowing and they can infect others before knowing that they had been infected.
Source: Hitoshi Oshitani, “Overview of Response to COVID-19” Japan Society of Public Health COVID-19 RelatedInformation Page URL: https://www.jhph.jp/covid/files/gainen_0402.pdf

4

2. Aim and steps of cluster response in the active epidemiological investigation

2.

Aim and steps of cluster response in
the active epidemiological investigation

2-1. Aim of the active epidemiological investigation□□

Identify clusters by making presumptions on source of transmission/mode of transmission.
Create a foothold by identifying persons who had close contact with infected individuals and could
be the source of the next cluster.

By isolating patients (confirmed cases) and those who have had close contact with them,further chain of transmissions can be contained.
□

Collect information about patients (first hand) and get it organized.

Sufficient and detailed clinical symptoms and behavior record between before becoming
symptomatic and after becoming symptomatic and getting tested for confirmed cases becomes
the starting point of the active epidemiological investigations.

2-2. Steps for the active epidemiological investigation
1. Check for incidence report□

Check to see if the case had an identified/assumed contact or connections among patients» Facility transmissions at healthcare facilities and nursing care facilities for elderlies, etc. will
have different response method. Check for appropriate response based on rules put forth byeach municipality.

□

Evaluate and estimate transmission risks from patient’s age, sex, background (job, residence,
range of activity, lifestyle, etc.).

□

There are cases where you would not be able to check for an incidence report and would need to
conduct interviews solely based on incidence information. It would be good to think through what
information needs to be collected prior to conducting the interview.

2. Decide how to communicate with patients□

Decide on interview method (in person, phone, etc.). Consider the risk of transmission andconduct phone interview as much as possible. If it needs to be done in-person, implement
prevention measures for contact and droplet transmissions. (check Appendix 2: Refer to guideline
for active epidemiological investigation).

□

Check where the patient is (self-isolating at home, hospitalized, somewhere else other than home,etc.).

□

There may be reasons, such as severity of symptoms (moderate to severe symptoms), thatprevents patients from being interviewed. Check to see who might be available to be interviewed(someone who is aware of the behavior record of the patient).

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan5

3. Conduct interview with patient (or families, etc.) and enter into necessary
survey forms (check Appendix 2: Refer to guideline for active epidemiologicalinvestigation)
Paperwork that need to be completed (do not aim for 100%, speed is important)
Survey form 1: patient information (basic information, clinical information)• Focus on necessary information and interview while giving considerations to patient’s status.
Survey form 2: Behavior survey between 14 days before developing symptoms and diagnosis• Make assumptions around source of infection (who), mode of transmission (where), exposure torisk factors (3C), and find clusters.
•

Even if survey for the last 14 days isn’t possible, be thorough in asking about “1 week before
developing symptoms” which is when the risk of transmission is higher.

Survey form 3-1: Behavior survey after becoming symptomatic (guidelines published on April 20th
has revised this to 2 days before becoming symptomatic).
• Changes in symptoms, whether or not if they have come into contact with others and how closethe contact was, and identifying those who had close contact (list them on Survey form 3-2).
Survey form 1, 2, 3-1, and 3-2 are available on “Guidelines on conducting active epidemiological investigations for
COVID-19 patients” published by National Institute of Infectious Diseases (https://www.niid.go.jp/niid/ja/diseases/ka/
corona-virus/2019-ncov/2484-idsc/9357-2019-ncov-02.html)

Q&A:

when you are perplexed about a judgment, when you don’t know what to do
Part1: Regarding patient and their families’ words or health/emotions at time of interview

Q1. If you receive abusive language or complaints from the patient
Sometimes, patients and their families may take out their anger or dissatisfaction on you. Whenthey are angry, they are not angry at the PHN. When a patient or a person who had close contact
is showing anger, do not condemn or deny them, and accept their emotions. Once you have shown
sympathy, ask what specifically they need help with.
Prior to visiting patients, agree on steps to take if or when this occurs (example: switch with a malestaff, show help card, etc.). Abusive language and complaints could be as a result of emotional
confusion. In such case, take a deep breath and calm yourself down to handle the situation. Please
do not try to take it all on yourself and handle it as a team.

Q2. If patient asked to cancel the interview because of their health condition
Let’s always remember that pneumonia could be causing difficulty breathing, slug-gishness, or highfever. Long interviews will increase stress on both your mental and physical health. Do not attempt tocollect all information, but rather, see things from the patients’ perspective and ask questions. If they
ask to cancel, decide on additional information collection method or date and do it another time.

Q3. If patient is experiencing deep sadness (suddenly developed severe symptoms,
or handling families of deceased patients, etc.)
It is natural to cry when experiencing loss of something important or someone important. Rather thanproviding a superficial encouragement or consoling, it is important to listen and empathize. However,
it is also important to accomplished the purpose of the interview. Do not try to resolve everything rightthere and then, but handle the situation by introducing ap-propriate support, etc.. Do not get too close
to their emotions and maintain a healthy distance.

63. Tips for interviews

3.

Tips for interviews

Questions should be based on each municipalities specific response policies. Please use this toprevent from forgetting to ask certain questions or leaving something out.

1. Basic principles
Importance in building trusts
In behavior survey, there are times when you have to discuss things that people may not want to talkabout and keep as secret. It would be important to develop trusts within the limited time and given
situation.
Understand the situation the patients are put in
There are cases where time has passed between developing symptoms to getting tested or between
getting tested to getting a diagnosis and memory becomes hazy. There are times when they may not
be in best health conditions and cannot take sufficient time to do the interview. There are also times
when they may have strong opinions (criticisms or complaints, concerns) regarding testing or access tohealthcare and may express them.
Ask for cooperation while sympathizing with their concerns within the limited time available
Show empathy, such as “that must have been difficult” or “it is very worrisome what could happen
going forward”, and ask for cooperation as much as their health allows them.

2. Items to request (introduction)□

I am XXX (name) with XXX (affioiation). How are you feeling?

□

I would like to ask you questions today about your recent activities. Identifying where you could
have gotten infected would be extremely important to prevent the increase in transmissions going
forward. Let’s all work together to prevent the virus from spreading.

□

Let me ask you about who or where you might have contact. We would not contact any persons offacilities without your permission. I would like to discuss with you at the end how to explain to themand how to contact.

3. Identifying the date of onset and progress of conditions
Depending on “when you have had changes in your health condition”, what days I would like to ask
you about your activities will be different. So first, please tell me what date was the first date when
you developed symptoms. The following are examples of the symptoms. What was the date when you
began seeing these symptoms? What kind of symptoms were they? How have your symptoms changed
from then?
Fever (higher than usual, even if lower than 37.5 oC), cough, sluggishness, sore throat, runny nose,
stuffy nose, headaches, diarrhea, joint pains/muscle pains, nausea, redness of eyes, abnormality insense of taste

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan7

By listing specific symptoms, there may be a light bulb moment when the interviewee may
remember something and provide new information. Identifying the date of onset of symptoms
will determine the scope of interview, so do it very carefully.

4. Steps in interviewing

Date of onset

Identifying thowe who have
had close contact from
2 days before onset ofsymptoms to today

From 2 days before onset to
14 days before
Estimate source and mode oftransmission identify clusters
2days before onset - 1 week before
is particularly important

We are trying to attain information on both people who have had close contact as well as you (patient)
starting from 2 days prior to onset of symptoms. I will ask questions by using “MM/DD (weekday), when
first symptoms appeared, as date of onset”.
First, I will ask about (1) MM/DD (weekday) (2 days before onset) - date of interview.
Next, I will ask about (2) MM/DD (weekday) (2 days before onset) - MM/DD (weekday) (14 days before
onset). If you remember something in the middle of the interview, please do not hesitate to tell me even
if it’s not in the order.
Do not go through questions rapidly one after another, but verbally acknowledge that you arelistening and repeat things back to the interviewee. Once the interviewee understands how the»interview goes, they may begin to tell the story in order themselves.

[1] Activities between 2 days before onset and now: identifying those who had
close contact Who is “those who have had close contact”“People who have had close contact” are those who had contact with a patient (confirmedcase) during the infectious period the following criteria (from guidelines)•

Have been living with patient (confirmed case) or have had prolonged contact (including riding
in a car or airplane, etc.)•

Have treated, nursed, or cared for a patient (confirmed case) without appropriate personal
protective equipment•

Have high likelihood of having come into direct contact with patient’s (confirmed case) airway
secretions or other contaminants such as bodily fluids•

Other: Have been in contact for more than 15 minutes with patient (confirmed case) without
necessary preventive measures in place at an arms length or face-to-face conversation
distance (about 1m) (comprehensively judge infectiousness of patient from symptoms, etc.)

Check for others around them who are not in good health

8□

Was there anyone that you came into contact with that were not in good health between MM/DD (2days before onset) - MM/DD (today)?

□

Do you live with anyone? How is their health?

3. Tips for interviews

Activities associated with “3C/high transmission risk” environments□

I will ask whether you have gone to any locations or environments that are “3C/high transmissionrisk” between MM/DD (2 days before onset) - MM/DD (today).

Check! Refer to P9, “Environments and activities in high risk of transmission/3C scenes”

Check where they work/study□

Where do you work? (what school do you go to? Do you have other part time jobs?)□

Does your employer/school know your current situation?

□

I will now ask about your activities and who you may have come into contact with at your work/school.

Check! For tips on specific interview, refer to p10 “priorities based on situation”[2] Activities between 2 days before onset and 14 days before onset: Find
the source/mode of transmission, identify clusters
Check for contact with high infection risk environment□

Let me ask you about your recent activities related to going to locations that are considered “highrisk of transmission/3C”. When did you use such facilities between MM/DD (2 days before onset) MM/DD (14 days before onset)?

□

Who else were with you? Have you heard if any of them have become ill since then?

□I would like you to especially remember activities between MM/DD (7 days before onset) until today.
If you have calendars or e-mail/phone/SNS records, please have that handy so you can reference
them. Recent memories are probably more lucid, so I will begin with the date of onset and go backin time. So first, I will ask about your activities on MM/DD (2 days before onset). What did you dothat day? How about MM/DD?

Environments and activities in high risk of transmission/3C scenes•

If you are visiting in person to conduct the survey, visualizing the high risk environments using thefollowing chart makes it easier to remember.

DinnerEvents
LeisureGatherings that include eating/drinking, Japanese style pubs (izakaya), pubs,
dining bars, snacks, bars, night clubs, girls’ clubs, girls’ bars, buffets, etc.
Concert houses, clubs, concert venues, theaters, opera houses, indoor sporting
events (kendo, judo, etc.), festivals, comic markets, meet and greets, photosessions, talk shows, seminars, study groups, exhibitions, etc.
Gyms, karaoke bars, pachinko, mah jong, net cafes, manga cafes, arcades,saunas, bedrock baths, yoga, off-the-clock gatherings, brothels, call girlbusinesses, etc.

TravelBusiness trips, returning home, trips, tours, capsule hotels, hospital visits,
nursing care facilities for elderlies

Other

Religious gatherings, PTA, townhall meetings, lessons, school events, camps,
dorm life, share house or shared office, etc.

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan9

[Example 1] If the patient says they attended a dinner
Which date? Where was the location? How many people did you go with? Do you know how big therestaurant was, and how many people were there? Were you dining in a private room? Was your seatclose to other patrons? How many hours did you spend there? Did you talk to anyone else other thanthose who you went with?
[Example 2] If the patient says they had been to a concert house
Where did you go? What was the maximum capacity at the venue, and how many people were there?
What time did you arrive? How long were you there for? Were you surrounded by people you know?
Was there a photo session or a meet and greet? Did you meet up with anyone before and after the
event and have a meal together? Do you know the schedule of those who were there with you?

Priority based on situation◎

Must be asked

Work related
If there are healthsupport centersat your workplaceof employment, it
may be possible
to ask your work
about the detailsof your activities
for your time
during work hours.
In such cases,
please prioritize
other items.

◎
◎
◎
◎
◎

◎
◎

◎
◎
◎
◎

｜

〇

Ask if possible｜△

Ask if there is time

Where do you work? Where is it located?
What is your job? (mostly desk work, making phones, visit clients, etc.)
Who at your work is most familiar with your situation?
When was the last day when you went into work?
Do you have a health support center at workplace and have an
occupational physician or an occupational health nurse?
(if yes) Can we contact the health support center at your workplace to ask
for the status of your workplace?
(if no) Can you provide contact information for someone we could reachout to regarding the health status of your workplace?
Were there any major events between now and 14 days before onset ofsymptoms?
Even if many people do not congregate, are there areas where multiple
people might get together, such as meetings or assemblies, lunch timecafeteria or break rooms?
Were there business trips for which you used bullet trains or airplanes?
When? Where did you go? With whom?
Have you participated in exhibits or business conferences?
Were there anyone who seemed to be ill around you?
Do you have any part time jobs outside of your normal job? Where were
you working?

○
○
○
○

Who were you with the most at work?
When did you come into contact with external people (clients, customers, etc.)
Where were you eating lunch, and with whom?
Were there any welcome parties or farewell parties? How many people
participated?
○ Do you use a changing room/break room? How many people use it?
○ (if you smoke) Where do you smoke when you are at work?
△△△△

What is your commute route like? What time do you commute?
What are your typical work hours?
Between 14 days before onset and now, what days were your days off?
When you go out to meet clients/customers, do you use trains or a car?
Do you ride in cars with other people?
△ When and in what kind of place did in-person meetings at work take place?
△ Is there a shared calendar that could show your activities?

103. Tips for interviews

School related◎ Where do you go to school? Where is it located?
◎ When was the last time you went to school?
◎ Who would be the best person to contact if we were to reach out to yourschool?
◎ Are you part of a team or an organization? When was the last time you
participated in an activity with them?
◎ Were there any major events where many people congregated at theschool between 14 days before onset and today?
◎ Were there anyone at school who appeared ill (such as coughing)?
◎ Who were you with the most at school?
◎ Who would best know your situation at the school?
○ When and in what kind of place (how many people in the classroom) were
you participating in lessons/lectures?
○ Were there any seminars, labs, exercises, practice, or trainings?
○ (if you smoke) Where do you smoke when you are at school?
○ Where were you eating lunch, and with whom?
○ How frequently were you participating in clubs/organization related
activities?
△△△△

Part-time job
relatedWhat is your school route like? What time do you go to school?
What are your typical school hours?
Between 14 days before onset and now, what days were your days off?
Are there club rooms/organization offices? When did you use them?

◎ What is your part time job? Please describe specifically. (such as, retail,
kitchen staff, cleaning, etc.)◎ How frequently were you going into your part time job?
◎ When was the last time you went to your part time job?
◎ Who were you with the most at your part time job?
◎ Were there anyone who were ill at your part time job?
○ How big is the break room/changing room at your part time job and how
many people use it?
○ (if you smoke) Where do you smoke when you are at your part time job?

Individual
activities/
lifestylebehavior◎ When did you go out to eat? Did you go with anyone else?
◎ Did you go to a healthcare facility, dentist, or a nursing care facility?
◎ Was there someone you saw often or a place you went frequently?
○ Did you go shopping somewhere?
○ Did you go to a salon/barber/massage/acupuncture/esthetician?

5. Request to provide information□

Thank you for your cooperation even though you are not feeling very well.

□Is there anything that you “forgot to mention, and just remembered” at this point?

□

From here, we will begin to check for people who may have gotten infected around the same timeand are already symptomatic as well as those who are still asymptomatic, and ask them to refrainfrom going out and monitor their health based on the information you provided.

□

Could you please share the contact information for those who had contact with you at XXX andXXX?

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan

11

4.

Handling of those who had close contact
with COVID-19 patients

1. Basic principles (purpose)
Request for health monitoring for persons who had close contact and to stay at homeAmong those who had contact with the patient (confirmed case) before 2 days before onset, identify
those who either live with the patient or have had prolonged contact (including those who could develop
symptoms or already have symptoms) and monitor their health and ask to stay at home and isolate (local
public health center will conduct health monitoring for 14 days).
Look for source of transmission and mode of transmission
Look to see if anyone could be identified in the patient’s (confirmed case) surrounding as the source oftransmission based on their activity record.
Interview should be conducted with the mindset to understand the overall environment surrounding thepatient (confirmed case), such as whether the chains of transmissions could already be occurring, hightransmission risk environment existed, who could have been in that environment, and if there may be
people who have had close contact with the patient that may not have been able to be identified by thestatement provided.

When close contact
can be assumed②
When you can identify thecircumstances or environment(work/school, event, etc.)①
When you can identify
the individual(family, colleague, friend, etc.)
Go to ① if you identify
someone who had
close contact

2. How to handle those who had close contact
When you can identify the individual
Preparation□

You will check if patient (confirmed case) has directly notified those who had close contact.

□

You will understand the relationship and contact frequency/status between patient (confirmed case)and those who had close contact.

[If patient (confirmed case) has notified them directly already]□12

You will check for the information provided by patient (confirmed case) or public health center
responsible for that region.

4. Handling of persons who had close contact with COVID-19 patients

Explanation□ You will confirm the contact record and explain that they have been identified as someone who has
had close contact.
[If patient (confirmed case) has notified them directly already]□As you have already heard from XXX (patient or public health center responsible for the region), I
am contacting you because I was told that you had spent time for ____ (frequency, condition) withXXX.

[If patient (confirmed case) has not yet notified them directly already (or cannot contact)]□ Sorry to reach out to you out of the blue. I am XXX (name), a PHNs from ____ public health center.
Do you have some time right not to talk?
□I am reaching out to you because there was someone who had been infected with COVID-19
among those you spent time with at ____ (contact details that you know, such as place, date,meeting/party etc.)□

Mr./Miss. XXX wanted to reach out to you directly, but they are not feeling very well, so we arereaching out to you on their behalf.

[For both cases]□ First, please tell me about your health status.

Priority based on health status◎

Healthmonitoring

Must be asked｜〇

Ask if possible｜△

Ask if there is time

◎ How are you feeling today?
○ Temperature (whether or not they have a fever, is it higher than usual
even if it isn’t higher than 37.5oC)○ Cough○ Difficulty breathing○ Sore throat○ Sluggishness○ Runny nose, stuffy nose
○ Headache○ Diarrhea, nausea, vomiting○ Joint pains, muscle pains○ Redness of eyes
○ Abnormality in sense of taste[If they already have symptoms]◎ When did you begin having symptoms?
○ Have your symptoms gotten worse? Has it gotten better?
◎ Have you sought help from someone, or seen a doctor? What did theysay?

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan

13

Healthmonitoring[If they have been to the Consultation Office for Returnees/People who
had contact]◎ Whether or not they have had a PCR test
If yes, check if they have gotten results.
If no results yet, check when the results will be available.
[If they have not yet sought any help]
Please handle in line with the manual provided by your local municipality
keeping in mind that they have had close contact with a confirmed case.

Risk fordeveloping
severesymptoms◎ Have you had any major diseases before?
○ Diabetes○ Hypertension○ Cancer○ Cardiovascular disease○ Smoking, COPD
○ Other diseases for which they are receiving treatment◎ How is the status of that disease right now? (treatment details, how it ismanaged, etc.).

Jobs thatare at higher
risk oftransmission
or chances ofcoming into
contact withthose who areat high riskfor developing
severesymptoms◎ What do you for a living? (healthcare worker, caretaker, restaurants, retail,etc.).
◎ Where do you work? Where is it located?
◎ Are you taking care of anyone? (do the ones they are caring for have riskfor developing severe symptoms such as diabetes, high blood pressure,high cholesterol, asthma, cancer, cardiovascular disease, etc.).
◎ When was the last day when you went to work?
→ For those who are working in jobs that have chances of coming into
contact with those who are at high risk for developing severe symptoms, if
deemed necessary, they could be subject for testing.
Check! Refer to guideline for active epidemiological investigation “handlingof those who have had close contact”

Request 1.
Monitor health for
14 days since thelast contact••

Going forward, I have 2 requests for how your activities until MM/DD (14days since the last contact).
First, I would like to check your health status everyday via phone or e-mail(method will follow what is put forward by local municipality).

[If they ask why the health monitoring is necessary]• We are worried about you developing symptoms.
[If they ask you about the possibility of transmission]•

14

Not everyone who has had contact with someone with the virus will get
infected. There are cases where no one around a patient is infected.

4. Handling of persons who had close contact with COVID-19 patients

Request 1.
Monitor health for
14 days since thelast contact•

However, there are also cases where a single patient has transmitted tomultiple people. This is why we need to monitor you to make sure you do
not become symptomatic.

◎ Can we agree on a rough time that I can contact you every day?
◎ Even if it is outside of the time that we agreed on, if you feel any
concerning symptoms, please let me know. My phone number is XXX XXXX - XXXX.

Request 2.

•

Refrain fromgoing out•

Second is to refrain from going out and staying home until MM/DD (14days since the last contact).
One of the characteristics of this COVID-19 is that the relationshipbetween “how severe the symptoms are” and “whether or not you can
infect others” is unclear. In fact, there have been cases where someone
with just a sore throat had infected many others especially since they were••able to remain active.
Please stay at home so that we can minimize the risk of you infecting
others and increase the transmissions.
I would need for you to contact your work/school. Do you have any
concerns?

Check! Refer to “priority based on situation” on P10-11 for interviews bysituation, such as work or school•

While you are staying at home, wash your hands, and use good coughetiquette (if you are living with others).
» Wear a mask (cover mouth/nose)» Cover mouth/nose with a tissue/handkerchief» Cover mouth/nose with a sleeve•

If you have to leave home, please refrain from using public transit andwear a mask if you have one.

[If it is really difficult to get their cooperation to stay home]•

A good example was the crew and customers on the cruise ship andpeople who came home on chartered airplanes. By isolating while
monitoring their health for 14 days after they have had contact withpatients and avoided contacting others, the transmission did not spread.
(Other: healthcare facilities in Wakayama, concert house in Osaka)[If they are seeing the patient (confirmed case) as the perpetrator andseeing themselves as the victim]• XXX and everyone else all got the virus somewhere through contact. No
individual is in the fault.
[If they ask about key things to remember for family members]
MHLW “If your family member is suspected of having COVID-19 What to becareful in the household”
https://www.mhlw.go.jp/content/10900000/000601721.pdf

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan15

Collect additional information◎ Were there others present when you were meeting Mr./Miss. XXX? (or when you were around
Mr./Miss. XXX at the time that you were at ___?)◎ Within the last 14 days, have you been at an event where many people were in attendance?
◎ Within the last 14 days, have you been overseas?
» Check for contact with high risk environment referencing P10-11 based on the subject.
Sharing information□ Information on symptoms of people who have had close contact and others who had contact
should be relayed to the public health center responsible for the region where the patient(confirmed case) resides so that all information can be aggregated.
Cases/organizations for which location or environment can be identified (people who had close
contact will be selected later)
Cases where information on patient (confirmed case) will be disclosed (work, school, etc.)
Preparation□ (To the patient (confirmed case)) Please tell me the contact information, organiza-tion, and nameof someone who would be the point of contact. The point of person is typically someone who works
in the health office (occupational physicians, oc-cupational health nurses), HR, BCP department,or your direct manager (for students, often student affairs or school’s consultation office). Goingforward, we may need to contact them multiple of times and aggregate information, etc. so it would
be ideal to get in touch with someone who we could have smooth contact with.
□

Please inform them that the public health center will be in touch with them.

□

Public health center is planning to reach out to them on MM/DD.

Explanation/investigation□ (To the contact person) As you may have already heard from Mr./Miss. XXX, it has been confirmedthat Mr./Miss. XXX has been infected with COVID-19. As such, we are reaching out to their work/school to understand who they may have had contact with and the health status of people aroundthem.
□

Please let us visit you on-site and ask about contact.

□

When we do so, please provide the seating chart. Also, please list up the names of persons andhow that contact occurred between MM/DD - MM/DD as well as their current health status (whether
or not they have symptoms).

□

From Mr./Miss. XXX, we have been told that they had contact with Mr./Miss. XXX, but please checkto see if others have had contact. Mr./Miss. XXX said that the person who would likely know theiractivities the best would be Mr./Miss. XXX.

Check! Refer to “Work related” for priorities based on situation on P10 for interview items»

It is best to prepare and distribute documents on requests, process of investigation, and sanitization.

Identifying people who had close contact/responding to work place□ Based on information on contact, Mr./Miss. A, B, and C have had close contact with a patient. Since
the last date of contact, which was MM/DD, we thank for you co-operation by allowing them to stay16

4. Handling of persons who had close contact with COVID-19 patientshome and monitor health through 14 days after the last date of contact, which will be MM/DD.
□

For those who have had close contact, we will let you know how to reach them after we provide
information to the public health center in the area where the patient (confirmed case) is residing.
When doing so, we will ask more specifically about Mr./Miss. XXX who has symptoms.

□

Sanitizing of the building and facilities should be done using cloth with alcohol, etc. mainly where
people touch and where droplets could have been dispersed.

□

For now, the public health center will not issue guidance to close down the facility based on thefact that the patient (confirmed case) began showing symptoms there.

Cases where patient (confirmed case) information will not be disclosed
Explanation□□(For contact person) We have found that someone who uses your facilities have been infected with
SARS-CoV2. Due to the patient’s wishes, we cannot disclose their name, but we do know when
they used your facilities. Can we check the facility and use status by coming directly on-site?
If you can identify people who were using your facility between XX:XX~XX:XX on MM/DD, pleaselist them up. Id you cannot identify, please provide roughly how many people might have been
there.

Deciding how to respond□ Please notify those people who were using the facilities around XX:XX about the potential contact
with an infected person. If contact is not known, please consider posting at the entrance of yourfacility.

Q&A:

when you are perplexed about a judgment, when you don’t know what to doPart 2: Regarding contacting person who had close contact, etc.

Q4. If they refuse to disclose contact information
Please ask for their cooperation by saying, “ By knowing that there is a possibility that you have been
infected, you can refrain from contacting people, monitor health, and change behavior to reduceincrease in transmissions. Please share the contact information so that correct infor-mation could beshared and stop the chain of transmissions.” Please also let them know that the information will behandled with utmost care.

Q5. If they are OK with disclosing contact information but do not want their namedisclosed
Please let them know that it is difficult to identify the people who have had contact without disclosing
their name. If they still refuse, ask for specific time and date of use and location by asking “we cankeep your name discreet to the facility, but will you help to narrow down the people who may have had
contact.”

Q6. If they ask for the public health center to not reach out to people who had
close contact
Say things like “Would you be able to reach out to them directly, and ask to (1) refrain from goingout, (2) reach out to XX as soon as their health condition changes, and keep in close contact? We canmonitor their health through you and ask for necessary information” and creatively ensure that yourcontact with them remains in tact.

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan

17

Appendix 1:
Mental health care for PHNs who are participatingin active epidemiological investigation
Getting a lot of information from someone who you have never met directly (or someone who you aremeeting for the first time) takes a lot of time and effort. Thank you so much for your hard work. It must
be extra stressful to not be able to take time and trying to prevent rapid increase in transmissions while
you might be able to do this with ample time during normal times. Please take care of yourself so thatyou can be in good condition tomorrow.

Self-care
PHNs, who are supporters, are also in the same situation as patients and families

In the midst of working on infectious disease response, there is a lot of confusion and stress. PHNs will
be impacted by stress and is easy to be affected both mentally and physically.

Self-care method

PHNs should know how to “self-care” so that they can prevent stress responses and effectively support
the efforts in infectious disease prevention.

Check!
□ If you see signs of stress, don’t be ashamed and admit to the feelings and what
you are finding stressful.
□ Pass on your responsibilities once you have reported your investigation andfacts quickly.
□ Positively evaluate your work… find meaning in your work.
□ Talk among your team about what you have heard and how you are feelingabout them.
□ Don’t try to do everything yourself. Know your limits, work with your team, andsupport one another.
□ Take breaks. Stretch. Take a deep breath.
□ Cherish the time you can spend with friends and family and rest up when youcan.
□ Think about how you may have grown through this experience.
□ If you feel that your stress level is too high, are drinking more than usual, arefeeling like you have to drink, or are experiencing careless mistakes or feel thatyou are more easily distracted and suffering from remembering things, those aresigns that should not be ignored. Take a break or talk to an expert.

18

Appendix 1: Mental care for persons who are involved in active epidemiological investigation

Organizational response
Clarifying roles and rotations

Clarify term of work, switch timing, responsibilities, and tasks for PHNs who are essential support staff.

Educate regarding stress on PHNs who are also supporters

It is important to educate the organization and workplace that stress that PHNs feel should not be anindividual responsibility but rather something that should be handled as a team. No matter how busy
it gets, try to foster a work environment that ensures that they are taking breaks regularly, talking to
one another, and supporting each other. Have meetings when possible and create opportunities where
small groups can hear opinions so that stress from work can be addressed.

Educate regarding residents’ emotional response

Educate staff ahead of time that it is possible that anger might be directed towards them as a result of
emotional response from residents.

Put value to the work

Someone within the organization with authority should clearly recognize the value of this work andthank the work that has been done.
Source: Tokyo Bureau of Social Welfare and Public Health, Mental Care guideline in disasters (May 2008) revised)
URL: https://www.fukushihoken.metro.lg.jp/tamasou/sonota_jouhou/saigaitaisaku.files/saigai.pdf

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan

19

Appendix 2:
Active epidemiological investigation guidelines
for COVID-19 patients
National Institute of Infectious Diseases, Infectious Disease Surveillance Center
April 20, 2020 ver.

Introduction
This document was created for public health centers to conduct active epidemiological investigations
quickly based on laws around infectious disease prevention and care for patients of infectious diseases
for COVID-19 patients (confirmed cases) that have been identified domestically.
In the “Basic Policy on COVID-19 Response (February 25, 2020)”, it was deemed that there has to bea response measure for isolated cases that are occurring and are not linked to a known cluster aroundthe country. In addition, in “Status of analysis and recom-mendation on COVID-19 Response (March
19, 2020)”, it was emphasized that in parallel to early identification of clusters, “citizens’ behavior
change” in accordance with each region’s status and “refraining from activities” especially for those
activities that are at higher risk would minimize the chain of transmissions and would help to bring eachregions’ trans-missions under control.

Overview of Cluster Response for COVID-19
Cluster Response that have been implemented in various parts of the country is centered aroundretrospective survey in identifying source of transmission and identifying those who had close contact
and monitoring (limiting activities), which are both traditional methods. If the source of cluster is obvious
and listing up the people who had close contact is easy to do, clusters will occur in an already limited
scope, thus will not lead to further chain of clusters.
However, SARS-CoV2, which causes COVID-19, causes many asymptomatic and cases with mild
symptoms, especially among younger generations. This makes it so that invisible clusters can occur
undetected and widely. It also makes it so that once such invisible clusters jump to high risk populations,such as the elderly, there is a risk that large mega clusters could occur simultaneously. That could be amajor threat to public health and healthcare. Increase in pa-tients will likely occur regionally or at a citylevel rather than nationally. This means that it would be important for regional and metropolitan publichealth centers and municipalities to be prepared, analyze the trends of this infectious disease, andconfront this disease.
If patients occur (especially ones with severe symptoms) at the scale that could com-promise thehealthcare system of the region, or that is a possible outcome, regional social activities must be shut
down and disable person to person transmissions forcibly; meaning, a measure must be implemented
to enforce social distancing. Under such measures to cut off modes of transmissions, cluster busting to
cut off each cluster do not make much sense. However, once the level of new cases decline to a certain
level, cluster response should be reimple-mented.
As of end of March, 2020, cases of COVID-19 is rising globally. In many countries, the number of cases
are seeing an upward trend. Going forward, even if domestic cases are under control and new cases
begin to decline, new clusters could form originating from imported cases. This means that cluster
response measures are necessary as long as there is COVID-19 some-where in the world.

20

Appendix 2: Guideline for active epidemiological investigation for COVID-19 patients

Positioning of this document
This document is an explanation of active epidemiological investigation which should be implemented
when cluster response is still meaningful. Meaning that, this is for when “isolated cases are occurringwith unknown links to clusters and in some regions there are small scale clusters” “before massive
increase in number of cases or after the number of new cases decline below a certain level”.
This document will provide information on identification and handling of patient clusters as indicatedby earlier overview. In addition, it also changed the definition of infectious period to the following forpatients (confirmed cases) related to those who had close contact:•

Period between 2 days before symptoms (suspected COVID-19 symptoms such as fever, acuterespiratory symptoms such as cough and difficulty breathing) through beginning of isolation»

Fever, cough, difficulty breathing, sluggishness, sore throat, runny nose, stuffy nose, headache,joint/muscle pains, diarrhea, nausea, vomiting, etc.

How to think about the active epidemiological investigation
Each municipality should be able to implement active epidemiological investigation efficiently, identify
individual patients and find clusters to determine the source of transmis-sions, know and manage
those who had close contact (enclosure), or implement measures to ask to stop operation of highrisk facilities or ask to refrain from high risk activities so that next cluster chain can be prevented andstop transmissions with support of experts of Cluster Re-sponse Taskforce put in place by MHLW on
February 25 and experts from National Institute of Infectious Diseases.
Contact person at municipalities for COVID-19 response support will be centralized under the Cluster
Response Taskforce for a while, but request for support and coordinating for local epidemiologicalsurvey will continue to be also done through NIID Infectious Disease Surveillance Center and FETP
(Field Epidemiological Training Program). NIID and Cluster Re-sponse Taskforce will closely collaborate
and work to contain transmissions as quickly as possible.
Definitions•“Patient (confirmed case)” is someone who was “suspected of having COVID-19 based on clinicalsymptoms and was diagnosed as COVID-19 through diagnostic testing”•“Patients with similar symptoms” is someone who was “suspected of having COVID-19 based onclinical symptoms and was diagnosed to have non-COVID-19”•“Infectious period for patients (confirmed case)” is 2 days before onset of suspected COVID-19
symptoms such as fever and acute respiratory symptoms such as cough and difficulty breathing
through beginning of isolation.
»•

Fever, cough, difficulty breathing, sluggishness, sore throat, runny nose, stuffy nose, headache,joint/muscle pains, diarrhea, nausea, vomiting, etc.

“Persons who had close contact” is those who meet the following criteria among those who cameinto contact with “patient (confirmed case)” during the infectious period»

Have been living with patient (confirmed case) or have had prolonged contact (including riding
in a car or airplane, etc.)»

Have treated, nursed, or cared for a patient (confirmed case) without appro-priate personal
protective equipment»

Have high likelihood of having come into direct contact with patient’s (con-firmed case) airway

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan21

secretions or other contaminants such as bodily fluids»•

Other: Have been in contact for more than 15 minutes with patient (confirmed case) without
necessary preventive measures in place at an arms length or face-to-face conversation
distance (about 1m) (comprehensively judge infec-tiousness of patient from symptoms, etc.)“Patient cluster” is group of patients who could potentially lead to series of clusters (continuous
chain of clusters) and could lead to a mega cluster. Up to this point in Japan, not all infected
persons have created secondary transmission cases. About 10~20% of all patients are likely
contributing to occurrence of secondary transmissions. Based on this knowledge, early identificationof this cluster and responding quickly is the key to prevent increase in transmissions.

Subject of active epidemiological investigation•

Those who will be subject of active epidemiological investigation are “patients (confirmed cases)”and “Persons who had close contact”. If the likelihood of “patients with similar symptoms” becoming
a confirmed case is high, assume that they will become a confirmed case and consider them asubject for active epidemiological investigation.

•

For some reason, if someone is prescribed a diagnostics test while having no symptoms and weredeemed to be “asymptomatic pathogen carrier (do not have clinical symptoms but was diagnosed
as COVID-19 through a test)”, based on sample collection timing and epidemiological information,
evaluate the likelihood of developing symptoms as well as the size of impact of transmission for
those who had come into contact. Then determine the necessity of contact tracing on a case bycase basis.

Understanding regional transmission status•

Public health centers will analyze information such as reports of “patients (confirmed cases)” or“patients with similar symptoms”, number of consultations at Consultation Office for Returnees andPeople Who Had Contact, and information on people who came back from abroad so that they canassess the cluster occurrence risk for that region.

•

Understand the number of PCR tests, number of confirmed cases, trend in positive rate, andnumber of isolated cases without known links to other clusters at municipalities. Especially therate of isolated cases without known links is important. When this rate becomes high, the cluster
risk in that region is becoming high, and will be considered as high importance region for cluster
response.

•

Also it would be important to understand the COVID-19 occurrence across the country andcompare commonality across various regions. By aggregating virus information broadly for genome
analysis that is being conducted by NIID Genome Analysis Center as part of administrative
investigation, it could be useful in explicating epidemiological links.

•

The guidance to reach out to Consultation Office for Returnees/People Who Had Close Contact will
be as follows as of February 17:
1. Have cold symptoms or fever above 37.5oC has lasted for more than 4 days (including those
who are taking antipyretics)
2. Have sluggishness or difficulty breathing
3. Have high risk of developing severe symptoms (elderly, people with underlying conditions suchas diabetes/heart failure/respiratory diseases, people who are on di-alysis, people who areusing immunosuppressants or anti-cancer drugs) and symptoms in 1) and 2) persists for morethan 2 days

22

Appendix 2: Guideline for active epidemiological investigation for COVID-19 patients

Investigation details•

Collect necessary information such as basic information, clinical information, suspected source oftransmission, people who had contact, etc. (Survey form 1, 2, 3-1, 3-2)•

For suspected source of transmission, when there are multiple “patients (confirmed cases)”, searchacross shared exposure source, identify risk factors of transmission, and implement appropriate
measures to prevent increase in transmissions (including warning those who may have been
exposed from common source).

•

As you search for “people who had contact” with “patients (confirmed cases)”, if there are those
who have higher risk of developing severe symptoms among candidates (example: elderly,
immunocompromised, etc.), “patient (confirmed case)’s” activity record needs to be examined more
carefully.

•

In estimating the source of transmission, from the viewpoint of identifying patient cluster, it should
be assumed that there are clusters around isolated cases, especially in regions where there are
multiple isolated case. Then investigate common exposure sources retrospectively. The necessityof this cannot be overstated. This is directly connected to not only that region, but also Japan’scontainment of increase in trans-missions.

•

In order to conduct active epidemiological investigations, subjects need to be narrowed carefully
based on information on “patient (confirmed case)’s” activity survey. Especially those who wereinvolved in activities that have multiple people talking (singing or chatting, etc.) in a closed
environment, including face to face, for some amount of time (crowded), in closed poor ventilated
space, are more at risk of creating secondary transmission cases.

•

As examples of such spaces, concert houses, boats, gyms have been named. Contact within suchindoor spaces will be investigated thoroughly for cases in addition to more traditional healthcare
facilities, social service facilities, work places, and schools.

•

However, in order to optimize and reduce burden of those who are conducting the survey,
information on risk factors that become available every day will be shared by Cluster Response
Taskforce and NIID proactively to make the investigation more effi-cient.

•

As we work to prevent cluster chains as a nation, families and others who are household membersof “patient (confirmed case)” among “those who had close contact” and had prolonged contact
period may need to be just asked to monitor health and refrain from certain activities, and publichealth centers may need to preserve their capacity for investigation for identifying other patients’clusters. Experts from NIID and COVID-19 Cluster Response Taskforce can support with evaluationand provide advice.

•

For “people who had close contact” who are subject of investigation as “patient (con-firmed case)”,health should be monitored with extra caution for 14 days of infectious period starting with the dateof exposure. As a prospective follow up, ask to contact the public health center prior to going to a
hospital if symptoms such as fever, respiratory symptoms, or sluggishness begin to occur. (Survey
form 3-3)•

For the daily follow up of “people who had close contact”, operation necessary between publichealth center and subject when contacting should be simplified as much as possible and reduceburden. (Example: instead of phone calls, use email)•“People who had close contact” would be considered as survey subjects if they develop a fever
or respiratory symptoms. This would be symptom development for someone who is at high riskof transmission. Since the goal is to contain transmission at the cluster level, regardless of theseverity of symptoms, necessity of testing would be judged by the treating physician.

Guide on Active Epidemiological Investigation for Public Health Nurses In Response to COVID-19 in Japan23

•

As a general rule, “people who had close contact” but are asymptomatic who are under healthmonitoring would not be subject for COVID-19 testing (exemptions will be noted later). Healthmonitoring will be done with measures to reduce transmission risk in place, such as isolating at
home.

•

If you are going to test those who are asymptomatic, it should be explained to the subject that thetest would not directly translate to a response measure because even if the virus is present, it is
not known at what timing it could be detected, negative test result does not rule out infection, andfurther measures to reduce transmission risks must be continued such as staying at home andmonitoring health status. It is important to gain understanding for reasons why testing may not be
carried out. It should be noted that for “people who had close contact” and are at higher risk ofdeveloping severe symptoms, their health status should be monitored closely.

Preventive measures for transmission during investigation•

If face to face interview is to be conducted by a PHN conducting active epidemiologicalinvestigation, it is necessary to wear a surgical mask and ensure appropriate hand washing, etc. is
done.

•

If interview must be conducted to a subject who has symptoms such as a cough, get the patient
to wear a surgical mask. In addition to the surgical mask and hand washing, the PHN should also
wear eye protective gear (goggles or face shield).

Handling of people who had close contact

24•

Public health center should issue guidance that people who had close contact should follow good
cough etiquette and hand washing during the period when their health is monitored and to pay
attention to their health status. Avoid going out unless essential. If they must go out, ask to avoid
public transit. Also ask to wear mask when going out and make sure to keep hands sanitized.

•

As mentioned above, as a general rule, “people who had close contact” but are asymptomatic who
are under health monitoring would not be subject for COVID-19 testing. However, if the “person
who had close contact” is a healthcare worker or working in jobs that has contact with high risk
populations and would necessitate the evaluation of transmission status or if clusters are occurringin succession and epidemiological survey is deemed necessary, they could become subject totesting.

•

Those who are living with “people who had close contact” should be told to wear masks andsanitize hands.

•

Refer to “If you suspect COVID-19 for your family Things you need to be aware - 8 key points -”https://www.mhlw.go.jp/cotent/10900000/000601721.pdf•

Discarding trash and washing linens and clothes for those who had close contact should be done
as usual.

•

If someone who had close contact has a small child, refer to “How to deal with students who havecome from abroad due to COVID-19 (as of 3/26) (notice) (March 26, 2020)” released by Ministry of
Education https://www.mext.go.jp/content/20200326-mxt_kouhou01-000004520_3.pdf•

To ship samples from healthcare facilities, refer to “Manual for sample collection/shipment for 2019nCoV (SARS-CoV2) infection”