[Construction of a tool for risk assessment of infectious diseases in a workplace--as a primary precaution]

We describe here a tool for risk assessment and management of infectious diseases in a workplace. This was constructed as a primary precaution for the prevention of infectious diseases in a workplace, not to be used as a countermeasure of diseases in the time of or after an occurrence. The tool grades risk levels of each of the factors influencing infectious diseases in the workplace and an assessment based on the total point are given. Ordinary workplaces should be chosen, such as factories and office buildings, not places where medical experts or hygienists work, such as hospitals, schools and concessionaries, etc. Three risk factors for infection are pathogens, route and human host. The factor of a pathogen is divided into two groups, spreadable (from human to human) and non-spreadable. The risk of spreadable pathogens is assessed by the ages of workers, CO2 concentration and air volume, and the combination of the existence of common places and collaborative work. The risk of non spreadable pathogens is evaluated by the ages of workers, air current and air volume, and existence of equipment generating aerosol. In cases where the total point is over 7, the risk is assessed as high level (group A) and daily measures must be taken, such as ensuring proper operation of the infection control committee, education, management of working conditions and management of working environments. In cases where the score is 5 or 6, the risk is assessed as intermediate level (group B) and daily measures are recommended, such as ensuring proper operation of the infection control committee and education. In the case of a score less than 4, the risk is assessed as low level (group C) and these daily measures are not necessary. Instead, an infection control committee should be organized and concrete measures should be taken upon an outbreak of an infectious disease.