Abstract
Background: At the campus of Japan Coast Academy in January 2017, 37 of 150 students developed influenza (situation A). Besides, 18 of 56 students at the training ship and 13 of 109 students at the campus of the academy developed influenza in January 2019 at same time (situation B and C). The rare data of the three situations including behavioral history data of students, daily clinical data of influenza-positive students and social contact data of students were collected and directly analyzed. Then, using a proposed spatio-temporal Susceptible – Exposed – Pre-infectious – Infectious – Recovered (SEPIR) model, the incubation period and the infectivity rate from asymptomatic people were calculated. And multiagent simulation (MAS) of influenza epidemic has been performed using spatio-temporal SEPIR model and has been validated.
Aim: Effective non-pharmaceutical interventions to prevent influenza epidemic is described.
Methods: The epidemic is defined using ratio of daily patients in the community. Then, situation A and B are classified as epidemics, but situation C is not. Using the validated MAS, three measures of infection control (preventive measure such as wearing mask, school closure when 20 % of patients are discovered and that when first patients are discovered) against influenza in the two epidemic situations A and B are evaluated. The criteria for evaluation are the frequency of epidemic and the ratio of total patients.
Results: The frequency of epidemic by the school closures as infection control measure is 100 %, whereas, those by the preventive measure are low (4.5 % and 22.9 %) in two epidemic situations. The ratio of total patients by the school closures are above 80 % and those by the preventive measure are low (7.6 % and 23.0 %) in two epidemic situations.
Conclusions: MAS suggests that the preventive measure such as wearing masks, washing hands and better ventilating rooms is useful. Then, the preventive measure is recommended after winter vacation or three-day weekend in January not school closure.