key: cord-0697039-lh4cs5qz
authors: Xie, Qing; Wang, Jing; You, Jianling; Zhu, Shida; Zhou, Rui; Tian, Zhijian; Wu, Hao; Lin, Yang; Chen, Wei; Xiao, Lan; Jin, Xin; Li, Jianjuan; Dong, Jie; Wu, Honglong; Zhang, Wei; Li, Jing; Xu, Xun; Yin, Ye; Mu, Feng; Chen, Weijun; Wang, Jian
title: Effect of large-scale testing platform in prevention and control of the COVID-19 pandemic: an empirical study with a novel numerical model
date: 2020-03-18
journal: nan
DOI: 10.1101/2020.03.15.20036624
sha: 08e53d107d66c898ad147e0100d3a955e40103ac
doc_id: 697039
cord_uid: lh4cs5qz

Background: China adopted an unprecedented province-scale quarantine since January 23rd 2020, after the novel coronavirus (COVID-19) broke out in Wuhan in December 2019. Responding to the challenge of limited testing capacity, large-scale standardized and fully-automated laboratory (Huo-Yan) was built as an ad-hoc measure. There was so far no empirical data or mathematical model to reveal the impact of the testing capacity improvement since the quarantine. Methods: We integrated public data released by the Health Commission of Hubei Province and Huo-Yan Laboratory testing data into a novel differential model with non-linear transfer coefficients and competitive compartments, to evaluate the trends of suspected cases under different nucleic acid testing capacities. Results: Without the establishment of Huo-Yan, the suspected cases would increased by 47% to 33,700, the corresponding cost of the quarantine would be doubled, and the turning point of the increment of suspected cases and the achievement of "daily settlement" (all daily new discovered suspected cases were diagnosed according to the nucleic acid testing results) would be delayed for a whole week and 11 days. If the Huo-Yan Laboratory could ran at its full capacity, the number of suspected cases could started to decrease at least a week earlier, the peak of suspected cases would be reduced by at least 44% and the quarantine cost could be reduced by more than 72%. Ideally, if a daily testing capacity of 10,500 could achieved immediately after the Hubei lockdown, "daily settlement" for all suspected cases would be achieved immediately. Conclusions: Large-scale and standardized clinical testing platform with nucleic acid testing, high-throughput sequencing and immunoprotein assessment capabilities need to be implemented simultaneously in order to maximize the effect of quarantine and minimize the duration and cost. Such infrastructure like Huo-Yan, is of great significance for the early prevention and control of infectious diseases for both common times and emergencies.

nucleic acid testing results) would be delayed for a whole week and 11 days. If the Yan Laboratory could ran at its full capacity, the number of suspected cases could 30 started to decrease at least a week earlier, the peak of suspected cases would be reduced 31 by at least 44% and the quarantine cost could be reduced by more than 72%. Ideally, if 32 a daily testing capacity of 10,500 could achieved immediately after the Hubei lockdown, 33

To cope with that, the Wuhan government made another key strategic decision to build 77 an emergent clinical virus testing infrastructure on Jan 29 th , i.e. the Huo-Yan Laboratory, 78 with a testing capacity over 10,000 per day ( Figure 1 ). Huo-Yan was expanded into a 79 site of 2,000 m 2 within a week from an existing laboratory that continuously delivers 80 testing results. Since Huo-Yan put into use on Feb 5 th , its testing capacity kept stably 81 increasing due to the automated nucleic acid extraction device and optimization of 82 procedure. Then Huo-Yan have achieved 14,000 testing capacity per day on Feb 9 th 83 along with the original site and exceeded 20,000 testing capacity per day on Mar 1 st . 84 . CC-BY-NC-ND 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020 . . https://doi.org/10.1101 /2020 And finally substantially contributed to achieve the "daily settlement" ( is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint According to the modified SEIR model by Yang et al [1] , after taken the whole province 128 quarantine measures in Hubei, the infected cases decreased from 43,000 on Feb 25 th to 129 34,000 on Mar 6 th . The suspected patents were usually with characteristics of fever and 130 and control of COVID-19 ( Figure 3 ). Unlike the common dynamic model used only 141 linear differential equations, this model applied the increasement of testing capacity 142 into account. Since the quarantine measures in Hubei, the contact probability among 143 people was reduced, which significantly reduced the possibility of large-scale 144 transmission. Meanwhile, due to quarantine, people were more alert to fever and other 145 symptoms, leading to more patients surged into the hospital and a continuous 146 increasement suspected cases. The purpose of nucleic acid testing was to 1) identify 147 patients with COVID-19 from the uninfected, and allow them to be hospitalized; 2) 148 after the symptoms disappear, the inpatient with more than twice negative testing results 149 (the interval must be more than 24 hours) could be discharged [3] . 150

The conversion efficiency from suspected to hospital admission depended on the testing 152 capacity (TC(t)), the number of existing and newly discovered the suspected cases, 153 however there was a bottleneck of nucleic acid testing. As soon as the daily testing 154 capacity was greater than the existing suspected plus the newly suspected of the day, 155 the "daily settlement" of suspected cases could be achieved. 156

The differential equation derived from the following models: 158

CC-BY-NC-ND 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint 

The parameters in the model were as is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020 . . https://doi.org/10.1101 /2020 The simulation result corresponded well with the trend of suspected cases by Health 190 Commission of Hubei Province, and the positive rate of the tests per day was around 191 50%, also consistent with the positive rate data from Huo-Yan. The effect of increased 192 testing capacity was significant, which was largely up to the government's decision and 193 the expansion of the hospitals and clinical testing laboratories (Figure 4) . 194 195 Due to the insufficient testing capacity at the beginning of the province-scale quarantine, 196 the number of suspected cases rose to over 23,000, which became a "dammed lake" for 197 delayed diagnosis and led to social panic. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint 11th 2020 by WHO. The quarantine of an entire district, city or a region could be 222 adopted as part of the measures by the government. In Italy, for example, more than 15 223 million people were placed in the country-based quarantine on March 8 th [5] . Timely and 224 accurate clinical test is essential for identifying the infected, cutting off the transmission, 225

and protecting the susceptible. The large-scale, precise, and reliable testing capacity is 226 highly required to reduce the panic accompanied by the drastic quarantine measures. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020 . . https://doi.org/10.1101 /2020 is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted March 18, 2020. The simulation results using the Huo-Yan factual operation data (line, red) corresponds 347

Modified SEIR and AI prediction of the epidemics trend 290 of COVID-19 in China under public health interventions