Guidance for the Prevention of Influenza

  • Date:

Simple hygiene practices such as gargling and hand washing, as well as adequate sleep, nutrition and rest are the principal means of preventing the transmission of disease.

It is preferable that the group activity is suspended as early as possible (when more than two persons are absent due to influenza in the same period). However, an absence rate of 10% or 20% could be the threshold to suspend the group activity depending on cases. Please read the following information for details.

Report when infected with an infectious disease

Basic Measures to Prevent Infection and its Spread

  • Wash your hands and gargle regularly (when arriving at home or work, before eating, etc.)
  • Observance of a cough etiquette
    Wear a mask if you have any one of the following symptoms: coughing, sneezing, runny nose, sore throat, fever, nausea or vomiting. Until you wear a mask, cover your nose and mouth with a tissue when coughing/sneezing or cough/sneeze into your sleeve to avoid respiratory droplets being passed through the air (if you coughed/sneezed into your hands, wash them before touching anything).
  • Get sufficient sleep and practice other good health habits to stay fit.
  • The influenza vaccination can reduce the risk of flu illness by about 50-80% among the overall population during seasons when the influenza vaccine is matched to circulating viruses. There are the pros and cons of vaccination. However, if not contraindicated, the influenza vaccination is recommended since that brings many medical benefits to people. Influenza viruses are constantly changing, so the vaccine is updated each year based on which influenza viruses are making people sick, how those viruses are spreading, and how well the previous season's vaccine protects against those viruses. Therefore the influenza vaccination is needed every year. The 2017-2018 influenza vaccine is made to protect against the four viruses (two A viruses and two B viruses). It takes about 2-4 months after vaccination for antibodies developed in the body to provide strong protection against influenza virus infection. Considering influenza activity peaks in the Tokyo area, it is best that people get vaccinated between October and mid-December. To prevent side effects or complications caused by influenza vaccines, please consult your primary care doctor and receive influenza vaccination.

Student Group Activities
(Academic, Athletic League Activities, Student Circles, Seminars, Research Activities, etc.)

Prevention of Group Infection

In order to continue group activities without the risk of becoming infected, it is important that each member of the group take responsibility for their own health and that of others. It is advisable that all individuals take their body temperature (without the administration of antipyretic medications) before leaving home, let alone when they are sick. For fever over 37 degrees Celsius, the individual should take extreme precautions (e.g. wear a mask when going out, take temperatures regularly, etc.), and for fever over 37.5 degrees Celsius the individual should refrain from participating in any activities and seek medical attention. This will greatly reduce the risk of group infection.

Understanding the Progress of Group Infection and Taking Steps

It is important to know the spread of group infection at an early stage as possible when it occurs. When more than two persons are infected within the same group in the same period (the incubation period of influenza is usually 2 or 3 days), it is indicative that group infection has occurred and preventive measures must be taken. If more than ten persons are showing symptoms of fever above 38 degrees Celsius accompanied by acute respiratory symptoms (either a runny nose, stuffy nose, sore throat or cough) within seven days, it is indicative that the infection has spread within the group.

The supervisor in charge of the activity in such event must report to the Health Center, either online or by fax.

Measures to Control the Spread of Group Infection

The effective way to stop the spread of group infection is to suspend the group activity for a fixed period of time (for approximately one week from the time period when infection occurred) and to avoid contacts (including personal contacts) with other members of the group.

It is advisable to suspend the group activity as early as possible (when more than two persons are infected in the same period) to prevent the infection from spreading further and to reduce health risks. However, in circumstances where suspension of activities would have a significant social effect and cannot easily be imposed, the supervisor may choose to postpone the suspension and enforce precautionary measures such as temperature checks and other infection control. Academic activity is a matter of highest priority for students, and the reason school and class closures are decided based on absence rates (10% or 20%) is to minimize the potential effect on such academic activities. However, since delaying the suspension heightens the possibility of increasing the number of infected individuals at an accelerated rate, it is important that any sign of infection receives medical attention without delay. The Health Center provides consultations for supervisors to give careful consideration to the objectives of the activity and to take appropriate actions. Please bear in mind that the most important consideration for infection control is to reduce human health risks and take necessary steps in promoting prevention methods such as self-care practices (observations of symptoms, early intervention and treatment), in addition to adjusting group activity plans.

Alert for Severe complications

  • Although over 90% of the patients affected by influenza are cured , it is a viral infection with a high risk of severity, with some deaths reported every year. Regardless of whether the individual has a pre-existing condition, be alert to any signs of influenza and any signs of worsening should receive medical attention immediately.
  • Signs of increase in severity include breathing difficulties (even without fever), shortness of breath, continuing chest pain, vomiting and diarrhea, fever lasting for over three days and worsening of other symptoms. In cases of infants, such signs also include fast breathing, paleness, inadequate fluid intake, inadequate communication and grumpiness.
  • Below are the underlying diseases and conditions that are reported to have high severity risk when affected by Influenza.
・Chronic respiratory diseases [asthma, chronic obstructive pulmonary disease (COPD), etc.]
・Chronic cardiac diseases [congenital cardiac disease, coronary artery disease, etc.]Smokers are often unaware of having signs of COPD or coronary artery disease.
・Metabolic diseases such as diabetes and obesity
Kidney failures [chronic renal failure, dialysis/transplant patients, etc.]
・Other diseases that may compromise immune systems and those who are under such treatment.
・1-year-old to preschool children, persons who are over 65 year old or pregnant.