 By this, we can reflect the potential future influence on the infection spread due to the movements of S and E that are hard to detect by the infection test at the time of immigration .
<clarity>  By this, we can reflect the potential future influence on the infection spread due to the movements of S and E that are hard to detect by the infection test at the time of immigration .
 By this, we can reflect the potential future influence on the infection spread due to the movements of S and E that are hard to detect by testing at the time of immigration .