"All localities should scientifically and accurately organize nucleic acid testing based on the risk of epidemic situation, and neither increase the code layer by layer nor reduce the code at will." At the press conference of the joint prevention and control mechanism of the State Council held on November 17, Shen Hongbing, deputy director of the National Bureau of Disease Control and Prevention and an academician of the CAE Member, said that 20 optimization and adjustment measures require more scientific, more standardized and faster research and judgment on flow and risk in prevention and control work, Protect people's life safety and health to the greatest extent, and minimize the impact on people's normal production and living order. Only secret contacts will be isolated in a centralized manner. "In the future, when an epidemic occurs in China, only secret contacts will be isolated in a centralized manner." Shen Hongbing said that the cancellation of the judgment and management of secret contacts is a more scientific and accurate prevention and control measure based on the size of infection risk. This kind of people will no longer be isolated in a centralized manner, in order to make more effective use of prevention and control resources and service guarantee resources such as flow adjustment and isolation. "I don't think it is necessary to promote the management and control by directly judging the secret connection as secret connection in some places." Shen Hongbing stressed that while canceling the judgment of secret connection, all places should make quick judgment, quick detection and quick management and control for the secret connector. Once the nucleic acid test of the splicer is positive, the investigation and control of the splicer will be further carried out at the first time, one link at a time, with higher requirements. Optimization of trans provincial tourism management policy: "Twenty measures of the State Council's joint prevention and control mechanism have eliminated the level of medium risk areas, and the scope of high-risk areas is limited to buildings or units." Li Xiaoyong, deputy director of the Department of Market Management of the Ministry of Culture and Tourism, said that the basis of trans provincial tourism linkage management policy has changed. Li Xiaoyong said that the rectification of individual regions with "one size fits all", layer upon layer overweight and random restriction of trans provincial tourism business activities are conducive to the recovery and development of the tourism industry affected by the epidemic. The Ministry of Culture and Tourism issued a notice on November 15, which made it clear that cross provincial tourism business activities will no longer implement linkage management with risk areas. Cross provincial tourists need to take cross provincial transportation vehicles with a negative nucleic acid test certificate within 48 hours, and carry out "landing inspection" for cross provincial floating personnel. Travel agencies should actively guide tourists to take the initiative to conduct nucleic acid testing, and promote the forward movement of prevention and control checkpoints. Travel agencies and online tourism enterprises continue to suspend the business of inbound and outbound team travel and "air ticket+hotel", and the business of team travel in land border port cities will not resume temporarily. "Since the policy was released, the industry has responded positively and the public has paid wide attention to it. The local cultural and tourism departments will strengthen the management of key links in accordance with the principle of territorial management, and promote the epidemic prevention and control work and the development of tourism as a whole." Li Xiaoyong said. The frequency of nucleic acid detection has clearly stipulated 20 optimization and adjustment measures, which have clearly stipulated the normalization of nucleic acid detection and the regional nucleic acid detection after the occurrence of the local epidemic. Guo Yanhong, Director of the Medical Emergency Response Department of the National Health Commission, introduced that "according to the optimization measures for nucleic acid testing in the 20 measures, when an aggregated epidemic occurs, only when the source of infection and the transmission chain are unclear, when community transmission occurs and the epidemic base is unclear, will the regional full staff nucleic acid testing be carried out." Shen Hongbing explained that in areas where there is no epidemic, normal nucleic acid testing is for risk posts