Q & A on Coronavirus Disease 2019 (COVID-19)

April 1, 2020 version

Information for the Public

1 Information for all

Q1: How long is the average incubation period? (Is the coronavirus transmitted to others during that period?)

According to the World Health Organization, the incubation period of 2019-nCOV ranges from 1 to 14 days with median estimates of 5 days. It also recommends 14 days of follow-up observation for confirmed cases based on information from other coronavirus diseases.

More information on the coronavirus is available on the National Institute of Infectious Diseases website:  https://www.niid.go.jp/niid/ja/kansennohanashi/9303-coronavirus.html


Q2: Can the 2019 Novel Coronavirus (2019-nCOV) be transmitted from a person who presents no symptoms?

Although the possibility of transmission from an asymptomatic person has been reported (https://www.nejm.org/doi/full/10.1056/NEJMc2001468), little is known on how Coronavirus disease 2019 (COVID-19) spreads from person to person.
Generally speaking, with most respiratory viruses, people are thought to be most contagious when they are most symptomatic. https://www.cdc.gov/coronavirus/2019-ncov/about/transmission.html


Q3: How does human to human transmission of the novel coronavirus (2019-nCOV) happen?

For now, available evidence suggests transmission of 2019-nCOV occurs mostly via droplets which might be inhaled or touched by others.

-Infection by inhaling droplets occurs when an infected person coughs or sneezes. The virus within droplets is carried over a short distance and these droplets can be inhaled through mouths or noses of people around the infected person.
-Infection by contact occurs when an infected person covers coughs or sneezes with their hands and touches objects around them with those hands. The virus within droplets may stuck on the surface and others can be infected by touching their mouths, noses, or possibly, eyes, after touching the surface that has the virus on it. Possible channels of such transmission include hand straps of trains and buses, doorknobs, switches and buttons.


Q4: How can I avoid catching or spreading the coronavirus?

First of all, we advise you to wash your hands with soap and water frequently, or use alcohol-based hand sanitizer gel when soap and water are not available. When you have symptoms such as coughs and sneezes, please cover your mouth and nose properly (called “cough etiquette”, explained below). If you cover coughs and sneezes with your hands and touches objects around you with those hands, there is a chance of spreading virus via those objects. Properly covering coughs and sneezes is particularly important when you are in crowded places such as schools, offices and packed trains.


Q5: What is the “cough etiquette”?

It refers to the way you cover your mouth and nose with a tissue, handkerchief, or the edge of a sleeve to avoid spreading germs to other people. An illustrated description is available on the website:


Q6: When should I wear a facemask?

If you have symptoms such as coughing and sneezing, wearing a facemask is proved to be highly effective in catching the droplets, and therefore might help prevent the spread of viruses.

The effectiveness of wearing a facemask to protect yourself from contracting viruses is thought to be very limited. If you wear a facemask in confined, badly ventilated spaces, it might help avoid catching droplets emitted from others but if you are in an open-air environment, the use of facemask is not very efficient.


Q7: What does “close contact with infected persons” generally mean?

Generally speaking, it means:
- Touching an infected person directly, without anti-infective measures
- Meeting an infected person at a distance of around 2 meters (6 feet) or less
Latest information on the novel coronavirus disease (COVID-19) is available on the website of the National Institute of Infectious Diseases.  https://www.niid.go.jp/niid/ja/diseases/ka/corona-virus/2019-ncov.html


Q8: If it is suspected that I might have been infected with the virus, which medical institution should I consult with to receive testing and treatment?

If you have had cold symptoms or a fever of 37.5°C or over for four days or more, or if you have a strong feeling of weariness (fatigue) or shortness of breath (difficulty breathing), please consult with the consultation center for people with potential exposure to COVID-19 set up at your nearest public health center.
Please also consult with the consultation center if you are a senior citizen, have an underlying disease such as diabetes, heart failure or respiratory disease (e.g., chronic obstructive pulmonary disease) or receive dialysis, or take immunosuppressant drugs or anticancer drugs, and you have had the symptoms mentioned above for about two days. The consultation center for people with potential exposure to COVID-19 introduces people having a fever or cough to a medical institution where medical services for people with potential exposure to COVID-19 are available. The consultation center receives phone calls from people who are suspected to have been infected with the virus, and makes arrangement to ensure that they can see a doctor at a medical institution where medical services for people with potential exposure to COVID-19 are available. Please visit the medical institution you are introduced to, and refrain from visiting other medical institutions.
At present, the vast majority of people who have any of the above symptoms for a period less than the above have some illness other than COVID-19. If you are worried about having the flu or the like, please consult with your regular doctor as usual.
The consultation centers for people with potential exposure to COVID-19 are set up in each prefecture.
For more information, please access the dedicated webpage via the following URL and consult with the center in your area. Top page for information on consultation centers for potential exposure to COVID-19. 


Q9: Is there a cure?

Currently there is no specific antiviral treatment for COVID-19. People with COVID-19 receive supportive care to help relieve symptoms.
For more information, please see the website of the National Institute of Infectious Disease.


Q10: Who is prone to develop severe conditions?

Currently, only limited information is available. The risk is thought to be higher for the elderly and people with chronic medical conditions, as is the case with other types of pneumonia. A report says that approximately one-third to one-half of reported patients had underlying medical comorbidities, including diabetes, hypertension, and cardiovascular disease.
It is advisable for senior citizens and patients with chronic diseases to take extra precautions, such as avoiding public transportation and crowded places, in addition to daily precautionary measures.


Q11: How can I read the Ministry’s website in English / Chinese / Korean?

When you visit the Ministry’s website, please find the language button placed at the top left. Currently, machine translation system for English, Chinese and Korean is available.



Choose the language then, the notification below will be shown. Click the OK button and wait for a while. ホームページの言語切り替えの手順その3


Q12: Prevention measures taken at social welfare facilities for elderly people

The risk of developing severe symptoms is particularly high among the elderly and patients with underlying diseases. It is important to cut off the transmission of the virus, by not bringing the virus into nor spreading it at elderly care and other facilities. Therefore, the government is working with local municipalities, which have the authority to designate or supervise the respective facilities, and relevant groups, to ensure that preventive measures are thoroughly implemented, providing the points of attention to these facilities nationwide.    
The government urges facilities to take steps for cutting off the transmission, in accordance with the infection control manual released by the Ministry of Health, Labour and Welfare, such as exercising coughing manners, including wearing of facial masks, and hygiene by handwashing or use of hand sanitizer not only by the elderly and staff but also visitors and contractors; and thoroughly ensuring the wearing of masks, aprons, and gloves during service, handwashing before feeding care, and providing meals with clean plates.     
In light of the status of the novel coronavirus outbreaks, we are strongly requesting various measures including:
(1) Ensuring staff measure their body temperature before going to work, and if they have a fever or other symptoms, that they refrain from going to work;
(2) Visits are preferably restricted, except for emergencies and if truly necessary, and should such a visit take place, visitors’ temperatures must be measured and their visits must be refused in cases of fever; and
(3) Pick-up and delivery from contractors and others must be made only in certain parts of the facilities such as the entrance, and when entering the building, their temperature must be measured, and should a fever be found, their entry must be denied.


Q13: The reason for the initial negative results of the PCR tests turning positive (in such cases as the cruise ship)

There are several reasons behind the cases that some passengers have tested positive after disembarking from the cruise ship. For instance, it can be considered that, even if a person is infected with the novel coronavirus, the person might test negative as the number of virus particles has not increased enough to exceed the minimum limit of detection at the initial stage of infection. Therefore, when taking the test again after the number of virus particle has sufficiently increased, that person could be tested positive.


Q14:The rationale and structure of conducting PCR screening in Japan

The government will ensure the sufficient PCR screening capacity so that all patients can receive PCR tests when doctors deem necessary.

The PCR screening capacity has reached around 9,000 samples per day with the cooperation of the National Institute of Infectious Diseases and quarantine stations, as well as Public Health Institutes, private-sector screening companies, and universities.

PCR screening is now covered by health care insurance so as to facilitate the necessary tests for patients. Those who consult the Call Centers for Japanese Returnees and Potential Contacts (available 24 hours) and for whom it is deemed necessary to conduct screening by the respective outpatient facility for returnees and potential contacts, relayed by the call center, are eligible to request a test directly from one of the private-sector screening institutions without going through a public health center.

When medical doctors find necessary to conduct a PCR test, patients will be referred to outpatient facilities for returnees and potential contacts, and undergo screening based on the determination made by the doctors.

Aiming to prevent the refusal of test requests due to limited local screening capacity, the government will more closely facilitate the process to ensure that each area can conduct the necessary tests by sharing diagnostic reagents among wider areas.

At the same time, new rapid diagnostic test kits have been under development that can significantly shorten testing time.


Q15: Reasons for requesting possible patients refraining from immediately consulting medical institutions

First and foremost, most of the symptoms of a common cold, fever, lassitude, or difficulty in breathing, at this moment, are being caused by diseases other than the novel coronavirus disease, such as influenza. If a cold or influenza is suspected, it is advised to consult with a family doctor or other doctors nearby as usual.
Meanwhile, suspected patients of novel coronavirus are visiting outpatient facilities for returnees and potential contacts referred by the Call Centers for Japanese Returnees and Potential Contacts; when a person is not actually infected, visiting those medical institutions, which have outpatient facilities, without proper consultation, just because he or she is concerned about having an infection, will increase the risk of infection.
In the event of concern over infection by the novel coronavirus, it is advised to consult with the Call Centers. The list of medical institutions that have the aforementioned outpatient facilities is not disclosed. This decision is based on lessons learned during the 2009 novel influenza pandemic whereby it took time to provide care to those who needed urgent attention as many people visited certain medical institutions in some prefectures. This is a necessary response to prioritize the provision of care to those who need urgent attention (i.e. patients with severe symptoms who need intensive care). The government asks for the understanding of the public.


2 Information for pregnant women and parents with children

Q1: How 2019-nCoV infection in pregnancy affect the fetus?

If you are pregnant and diagnosed with pneumonia, your symptoms could become more severe than those before you got pregnant. However, such cases have not been confirmed among pregnant women infected with 2019-nCoV even in Hubei Province in China where the largest number of infection cases have been reported. It is not clear how infection in pregnancy will affect the fetus. But again, there are no confirmed cases of the virus causing problems to the fetus. For more information, please look at the following website. Japan society for Infectious Disease in Obstetrics and Gynecology: Coronavirus infection and pregnancy