Effectiveness of quarantine measure on transmission dynamics of COVID-19 in Hong Kong

Hsiang-Yu Yuan; Axiu Mao; Guiyuan Han; Hsiangkuo Yuan; Dirk Pfeiffer

the cumulative numbers with a crossover between the local and imported cases ( Figure 1B ) and transient dy-135 namics ( Figure 3 ). The predicted number of imported cases reached to a peak on 26 January ( Figure 3A ). These 136 imported cases immediately caused a wave of local infections. The number of daily newly detected local cases 137 reached to a peak around 2 February and decreased afterward ( Figure 3B ). period of approximately 5 days was reported [16, 19, 20] . We assumed all the infected persons can pass the border 146 before disease onset, which was defined as the incubation time. The results showed that the ratio can be low during the initial period but soon reached saturated values after 3 165 weeks both for imported and local cases ( Figure 6AB ). Generally the detection ratios of the imported cases were 166 higher than the local cases because the number of the imported cases were low. For local cases, 71%(46 − 90) of 167 which were detected, estimated by our model. One day delay of quarantine reduced about 10% of daily detection 168 ratio to 60%(39 − 74) ( Figure 6B ). Only 31%(20 − 39) of them could be detected or quarantined if quarantine 169 was delayed 6 days. The results showed that not only early quarantine can reduce reproductive number, but also 170 has a benefit on increasing overall detection ratio.