Presentation Information
[C07-04]The role of quarantine and its effectiveness according to the epidemic season
*Yusuke Asai1 (1. Japan Institute for Health Security (Japan))
Keywords:
quarantine,epidemiology,mathematical model
In recent years, the development of transport networks has dramatically increased the number of people travelling to and from other countries. This has been accompanied by a steady increase in the importation of emerging and re-emerging infectious diseases and their transmission to the public: since 2000 alone, international infectious disease epidemics have occurred, such as SARS, MERS and H1N1 influenza. The COVID-19 pandemic, which began in late 2019, has not ended despite the development of effective drugs and vaccines more than five years after the start of the epidemic.
The first step in preventing an international infectious disease epidemic is to prevent the importation of infectious diseases, and quarantine has been used for many years. Quarantine has played a particularly important role in island countries such as Japan, which are geographically isolated from other countries, and has also been used to buy time until domestic medical facilities can be established.
While effective in controlling the spread of emerging and re-emerging infectious diseases, quarantine also has a significant economic impact on industry, tourism and the food and beverage industry. Quantifying the effectiveness of quarantine and optimising the schedule are therefore important, but have rarely been discussed. Indeed, stopping 10 infected people in airport quarantine may not make much sense when domestic community-acquired infections have started and thousands of people are being infected per day. The role of quarantine may change when 80% of the population has been vaccinated.
In this study, using the COVID-19 epidemic in Japan as an example, we describe the domestic epidemic situation using the SEIR model and estimate the impact of continuous importation from abroad on the final size. In particular, we estimate the effect of imported cases on the spread of infection in three periods: the early stage of the epidemic when the number of infected people in Japan is still small, the middle stage of the epidemic when several thousand people are newly infected per day, and the late stage when most of the population has been vaccinated, and discuss the effect of quarantine in each period.
The first step in preventing an international infectious disease epidemic is to prevent the importation of infectious diseases, and quarantine has been used for many years. Quarantine has played a particularly important role in island countries such as Japan, which are geographically isolated from other countries, and has also been used to buy time until domestic medical facilities can be established.
While effective in controlling the spread of emerging and re-emerging infectious diseases, quarantine also has a significant economic impact on industry, tourism and the food and beverage industry. Quantifying the effectiveness of quarantine and optimising the schedule are therefore important, but have rarely been discussed. Indeed, stopping 10 infected people in airport quarantine may not make much sense when domestic community-acquired infections have started and thousands of people are being infected per day. The role of quarantine may change when 80% of the population has been vaccinated.
In this study, using the COVID-19 epidemic in Japan as an example, we describe the domestic epidemic situation using the SEIR model and estimate the impact of continuous importation from abroad on the final size. In particular, we estimate the effect of imported cases on the spread of infection in three periods: the early stage of the epidemic when the number of infected people in Japan is still small, the middle stage of the epidemic when several thousand people are newly infected per day, and the late stage when most of the population has been vaccinated, and discuss the effect of quarantine in each period.