
This report is current as of May 20, 2020.
Introduction
The Field Epidemiology Training Program of Japan (FETP-J) was established in 1999 with the aim of fostering field epidemiologists who can rapidly detect and respond to infectious disease outbreaks. The program is located within the National Institute of Infectious Disease (NIID), and staff from the Infectious Disease Surveillance Center (IDSC), the epidemiology division of NIID, oversee their training.
On February 25, 2020, in response to the outbreak of coronavirus disease 2019 (COVID-19) in Japan, a National COVID-19 Response Team (Response Team) was established in the Ministry of Health, Labor and Welfare (MHLW). Eleven current FETP-J trainees, several FETP-J graduates, and IDSC staff were assigned to the Response Team. The team’s primary focus was to investigate the cause of infections and the transmission routes of the virus, as well as to provide support to outbreak countermeasures. The team was dispatched based on requests from local governments, which were experiencing high numbers of COVID-19 cases, deaths, or an outbreak with major public health significance, such as an outbreak in a hospital setting.
The following is a summary of the FETP-J activities toward COVID-19 response from February 25, 2020 until May 20, 2020.
Activities
According to MHLW, there were 262 COVID-19 outbreaks around the country between February 25 to May 20, 2020, including 93 hospital-related outbreaks, 41 outbreaks in long-term care facilities, and nine outbreaks in facilities for the disabled. FETP-J responded to 74 COVID-19 outbreaks, which is approximately 30 percent of the total outbreaks that occurred in Japan during this period. Dispatch requests were sent from 30, out of a total of 47, prefectures, with a total of 45 people as part of the response team, including 13 FETP trainees and 17 FETP graduates. Of note, there were 13 FETP graduates, who are currently staff at local governments, also engaged in COVID-19 outbreak response efforts. Deployment days per request ranged from one to 54 days (a median of five days).
During the response, the team assisted in epidemiological investigations and had varied responsibilities, such as: data compilation, collection of descriptive epidemiology data, investigation of outbreak risk factors, identification of routes of infection, providing advice on infection control at medical and welfare facilities, as well as coordinating with local governments, other municipalities, and related organizations.

Summary of findings from the field
The team was involved in 36 hospital-related outbreaks (14 outbreaks in hospitals with less than 200 beds, 11 with 200-399 beds, and 11 with 400 or more beds). The median number of COVID-19 cases per facility, as of May 20, 2020, was 25 cases (range: three to 214). The inadequate practice of standard precautions, hand hygiene, zoning, and insufficient use of personal protection equipment (PPE) were the major drivers for hospital outbreaks. In addition, lack of information sharing and communication among stakeholders delayed the detection and response to hospital-based outbreaks.
There were 12 outbreaks at welfare facilities for the elderly, including long-term care facilities, nursing homes and day services. Overall, 408 cases were reported from these facilities, including 59 deaths. Two outbreaks, totaling 158 cases, were reported from facilities for the disabled. The main cause of outbreaks among these facilities was the introduction of the virus by facility users and employees. Compared to medical facilities, staff at these facilities did not have sufficient skills in and knowledge of infection control. The older age of the facility users, which in itself increases the risk of severe illness, was also a contributing factor.
When an outbreak occurred in a hospital or facility, many staff members became infected or were designated as close contacts and isolated from their workplace(s). This made it difficult for hospitals and facilities to maintain their functions. In addition, in many of these hospitals and facilities, employees and their families suffered from discrimination and prejudice due to COVID-19. Consequently, it is of significant importance to educate not only staff at the facilities but also the general public on basic COVID-19 knowledge and infection control in order to be appropriately cautious in their response to the disease.
Regarding outbreaks in community settings, the team responded to 15 outbreaks throughout the country during this period. They worked to support doctors and stakeholders in order to detect index and secondary cases quickly as well as provided them with detailed information on the COVID-19 outbreak in their area, which significantly improved the quality of medical interviews. The risk of a community-based outbreak of COVID-19 increased when individuals were in close contact with each other for long periods of time in densely populated spaces; this was found to be more likely in cases where people removed their masks, such as in a live music clubs, restaurants with meals and entertainment, changing rooms in sports gyms, at karaoke, etc. Despite the heavy burden placed on local governments, with increased activities including coordination of hospitalization of cases, active epidemiological investigations, and laboratory testing; those with successful responses to COVID-19 outbreaks shared important information with all the relevant departments regularly and had strong leadership with a clear command structure.
In addition to field investigations, the Pathogen Genomics Center of the NIID provided genome analysis for available samples. When combined with the corresponding epidemiological information, we found that whole genome sequencing and analysis provided additional understanding of the overall picture of the outbreak, including the sources of infection and the spread of the disease in the region.

Challenges
There were several significant challenges identified during active epidemiological investigations. For instance, getting thorough cooperation from a COVID-19 case was sometimes difficult based on fear of discrimination due to sharing personal information, excessive social harassment, and concerns of the potential impact on their social network, such as family members, colleagues, and friends. Furthermore, due to the lack of personnel to conduct epidemiological investigation, such as close contact tracing at health centers, the sources of infection and identification of close contacts was not well understood. As the number of cases with unknown sources of infection increased, the more difficult it became to accurately understand the spread of the COVID-19 in a given area. In addition, management and sharing of information among stakeholders, including MHLW, did not always function smoothly, which resulted in a lack of appropriate response and control of the outbreaks.
On the other hand, by conducting careful and thorough interviews and collecting information onsite, it was possible to reveal key epidemiological links, which later led to sufficient infection control and managing outbreaks in a short period of time. Thus, to achieve successful field investigations, it is important to secure sufficient, trained personnel who have experience and knowledge in field investigation, in addition to establishing a platform for information sharing with stakeholders.
Conclusion
This is a brief summary of the FETP-J response to the COVID-19 outbreak. In the absence of a reliable treatment or effective vaccine, the only proactive preventive measure is to collect information thoroughly on cases, including past activities and close contacts, in order to be able to identify those who have a high risk of developing COVID-19 and to implement effective infection control measures. Additionally, it is important that the same information be shared quickly between the appropriate stakeholders. Based on the findings of investigations, FETP-J and IDSC have issued several guidelines. As the number of COVID-19 cases resurges in Japan from mid-July, the battle of FETP-J continues.