Visual analysis of the prevention and control measures of COVID-19 in Chinese ports

doi:10.21203/rs.3.rs-2479954/v1

In 2022, COVID-19 solutions in China has entered a normal stage, and the solutions imported from ports have been transformed from emergency prevention and control measures to investigative long-term prevention and control measures. Therefore, it is necessary to study solutions for COVID-19 at border ports. In this study, literature related to COVID-19 prevention and control at ports from 2020 to September 2022 in the Wanfang database, CNKI, CQVIP database, and WOS core were searched. Citespace 6.1.R2 software was used for the visual analysis of researchers, research institutions, and keywords. A total of 170 articles were included for analysis. The research teams of the Chinese Academy of Inspection and Quarantine (CAIQ) and Beijing Customs District P.R.CHINA published more articles, and there was less cross-cooperation among research institutions. Keywords such as “COVID-19”, “epidemic prevention and control”, “port”, and “health quarantine” appear frequently. High-frequency clustering words were “#0 COVID-19”, “#1 risk assessment”, “#2 prevention and control mechanism”, “#3 infectious diseases”, “#4 public health”, and so on, indicating that risk assessment and other prevention mechanisms were the hot spots of current research.

COVID-19

Chinese ports

Prevention and control

Measures

CiteSpace

Big data

Visualization

The outbreak of COVID-19 at the end of 2019 has been a global public health emergency with the widest coverage, the largest number of infections, and the longest duration in recent years (Bu Hailong, Liu Guodong et al. 2022). With the emergence of imported variant strains, the overall national prevention and control strategy has been adjusted to “preventing import from the outside and rebound from inside”, and the epidemic prevention and control work has shifted from emergency management to regular and targeted prevention and control (Si Wei, Sun Xiaoling et al. 2021).

There are frequent exchanges of people in Chinese border ports. With the rapid development of the epidemic abroad, the number of high-risk people entering China has surged (Zou, Xu et al. 2021), posing a challenge to the existing epidemic prevention and control system at major ports within China (Han Pengyu, Bi Xiuxin et al. 2020). Since the outbreak of COVID-19, the customs and quarantine department has adjusted the solutions according to the actual work situation, which has prevented the spread of the virus (Deping 2020). In 2021, as the global impact of COVID-19 continues to expand, the number of mutated strains and imported cases continues to increase, and the focus of solutions has shifted to “preventing import from the outside”. All port departments have played an important role in strengthening joint prevention and control cooperation and tightening the closed loop of epidemic prevention and control (Zhang Wei, Song Linghao et al. 2020, Ju Chengfei, Bi Pengfei et al. 2021, Liao, Lyu et al. 2022). In 2022, COVID-19 solutions in China has entered a normal stage, and the solutions imported from ports have been transformed from emergency prevention and control measures to investigative long-term prevention and control measures (Zeng Wenge and Yue 2022).

Therefore, it is necessary to study solutions for COVID-19 at border ports. With the development of digitization, bibliometric analysis has become an important means of data mining and analysis in scientific research. CiteSpace analysis software displays the structure, rule, and distribution of knowledge through a visual atlas, and vividly displays network cooperation, research hotspots, frontiers, and disease development trends, which has important reference significance (Chen Yue, Chen Chaomei et al. 2015, LiZhong 2020). In this study, the bibliometric method was adopted to make a quantitative analysis of Chinese literature in the Wanfang database, CNKI, CQVIP database, and the WOS core collection. CiteSpace software was used to generate a series of visual maps, showing the hot topics and frontiers of literature research on COVID-19 prevention and control in Chinese ports. It also provided evidence for the formulation and implementation of future solutions in the post-epidemic stage at ports.

Data resource

The literature data were obtained from the Wanfang, CNKI, CQVIP databases, and the Web of Science (WOS) core set. The retrieval period was from January 2020 to September 16, 2022.

The search strategies are as follows: (1) Based on the Wanfang, CNKI, and CQVIP databases, a single Chinese journal search database was established, and an advanced search was conducted with the theme words of “COVID-19”, “prevention and control”, and “port”; The title of the selected literature was exported in Note Express format, including the author, research institution, title, journal, year of publication and other information. (2) Based on the WOS core set, the search topic was set as “COVID-19”, search results were refined to “port” and “prevention and control”, document type was set as article, English was set as the language, China was set as the country/region, and the complete records and references of the selected documents were exported in text format.

Data processing

The literature index that was downloaded from the Wanfang, CNKI, and CQVIP databases was imported into Note Express software for reprocessing, standardization of the name of the organizations, retention of the first-level unit, and filling in the missing information, such as author and unit. Duplicate articles, incomplete information, conference papers, conference abstracts, and other documents were excluded. The data file format could be identified using the CiteSpace software in Note Express. Finally, 163 valid references were included.

Analytical method

Citespace 6.1.R2 software was used to analyze the collaboration networks of authors and institutions, keyword collinearity, and cluster analysis. The analysis period was set from January 2020 to September 2022, with time slicing by year. By default, all the options in the Text Source were selected, the node types such as author, institution, and keywords were selected to run the software, and the relevant parameters were adjusted to optimize the graphs (Zou, Xu et al. 2021).

Literature review

From 2020 to 2022, a total of 170 articles were included for analysis, of which 163 were from the Wanfang, CNKI, and CQVIP databases, and 7 were from the WOS core collection. In the Wanfang, CNKI, and CQVIP databases, 50.92% (83/163) of the literature were supported by research grant funding. The largest number of articles were published in 2020, accounting for 46.01% (75 articles), while articles published in 2021 and 2022 accounted for 30.67% (50 articles) and 23.31% (38 articles), respectively. Among the screened databases, the Wanfang database was the dominant source of literature, accounting for 50.92% (83 articles), the CNKI database accounted for 31.29% (51 articles), and the CQVIP database accounted for 17.79% (29 articles). The most common source journals for the published articles were Chinese Frontier Health Quarantine (15.95%, 26 articles), Port Health Control (13.50%, 22 articles), China Customs (3.07%, 5 articles), and the Chinese Journal of Epidemiology (3.07%, 5 articles). In the WOS core set, all the identified articles (7 articles, 100 %) were supported by research grant funding, among which five articles were published in 2021 and two were published in 2022. The top three WOS theme categories were: Healthcare in Health Care Sciences Services, Health Policy Services, and Public Environmental Occupational Health. The journal sources of the articles were as follows: 2 articles in Healthcare and 1 article in each of the BMC Public Health, Frontiers In Public Health, International Journal of Biological Sciences, and Journal of Water Process Engineering and Sustainability.

Analysis of researcher cooperation network

In Wanfang, CNKI, and CQVIP databases, the scientific research teams that published the most articles were mainly from the Chinese Academy of Inspection and Quarantine (CAIQ, Han Hui et al.) and Beijing Customs District P.R.CHINA(Beijing Customs, Han Hui, et al.). In the WOS core collection, Zhejiang University published 2 articles, and Army Medical University, Chinese Center for Disease Control and Prevention, and Dalian Maritime University each published 1 article, respectively. The top 10 scientific researchers and research institutions in the field of COVID-19 prevention and control in Chinese ports were shown in Table 1.

Researcher analysis

Based on the visualization atlas analysis of literature from the Wanfang, CNKI, and CQVIP databases, the number of nodes generated by the collaborative collinear atlas of researchers was 98, the number of connections was 106, and the density was 0.0223. Research was carried out by groups within research institutions, but there was less cross-cooperation among researchers, and most of the small nodes were scattered, indicating that Chinese scholars should attach importance to academic exchanges and cooperation in this field (Figure 1). Han Hui, Sun Xiaodong, Jia Jiaojiao, and Wu Bo (n ≥ 6) ranked the top in terms of the number of papers issued. According to Price's Law , M_p=2.12, that is, 52 researchers (n ≥ 2) were identified as candidates for active authors in the study of COVID-19 prevention and control measures in Chinese ports.

Based on the literature on the WOS core set, the visualization atlas analysis showed that the number of nodes generated by the collaborative collinear atlas of researchers was 39, the number of connections was 117, and the density was 0.1579. Each of the researchers published one paper, and the researchers formed four large-scale collaborative networks, which indicated that Chinese researchers paid more attention to academic teamwork when publishing in foreign journals (Figure 2).

Analysis of research institutions

Based on the literature from the Wanfang, CNKI, and CQVIP databases, the visualization atlas analysis shows that the number of nodes generated by the cooperative collinear atlas of research institutions was 87, the number of links was 43, and the density was 0.0115, indicating that the research groups in COVID-19 prevention and control measures in Chinese ports were scattered, and there was less cross-institutional cooperation. Research institutions such as the CAIQ, Beijing Customs, General Administration of Customs (Beijing) International Travel Healthcare Center (Beijing ITHC), Dalian Maritime University, and Rongcheng Customs District P.R.CHINA published a large number of articles, which were at the forefront of COVID-19 prevention and control measures in Chinese ports (Figure 3).

Based on the literature in the WOS core set, the visualization atlas analysis showed that the number of nodes generated by the cooperative collinear atlas of research institutions was 19, the number of connections was 37, and the density was 0.2146. The research institutions formed two relatively large-scale cooperative networks, including eight research institutions such as Fudan University, Army Medical University, and the Chinese Center for Disease Control and Prevention (Figure S1).

Research hotspot analysis

Keyword collinear network analysis

Based on the visualization atlas analysis of the literature from the Wanfang, CNKI, and CQVIP databases, the keyword atlas of COVID-19 prevention and control measures in Chinese ports formed 109 nodes and 156 lines, with a density of 0.0265 (Figure S2). The nodes of “COVID-19”, “epidemic prevention and control”, “port”, and “health and quarantine” were large and appeared with high frequency throughout the study period, indicating that they were research hotspots in this field.

Based on the literature of the WOS core set, the visualization atlas analysis showed that there were 32 nodes, 87 lines, and a density of 0.1754 in the keyword atlas for the prevention and control measures of COVID-19 at Chinese ports. Due to the limited literature available, the large node was not been formed, and “infectious disease” was more relevant to other keywords (Figure S5).

Keyword clustering analysis

For the keyword cluster analysis of the Wanfang, CNKI, and CQVIP databases, the clustering module value of Modularity (Q value) was 0.7893（Q>0.3), indicating a significant clustering structure. The average clustering contour value (S value) was 0.9471(S>0.7), which indicated good clustering results. The top five high-frequency keywords were clustered into “#0 COVID-19”, “#1 risk assessment”, “#2 prevention and control mechanism”, “#3 infectious diseases” and “#4 public health” (Figure S4 and Table 2).

In 2020, the keywords focused on three clusters: “#0 COVID-19”, “#2 prevention and control mechanism”, and “#3 infectious disease”. The variety of keywords reflected the adoption in China of the “closed-loop management mode of joint prevention and control mechanism at ports”, according to the epidemic situation. The nucleic acid detection information management system played the role of “big data” analysis in nucleic acid sampling, providing accurate data for precise epidemic prevention and control. At the same time, Customs and other institutions strictly prevented the import of COVID-19 from overseas through waterways and land ports. In light of the COVID-19 epidemic, China has been exploring the safety working mechanism of “health quarantine” at border ports and has promoted the transformation of prevention and control methods by combining big data and intelligence analysis of infectious diseases.

In 2021, the type of keyword clusters increased, mainly concentrated in three clusters “#1 risk assessment”, “#4 public health” and “#5 Ministry of Transport”, among which “risk assessment” was the largest number. Some researchers judged the risk level of epidemic input based on the prevalence of virus mutations. The Ministry of Transport has issued regulations on disinfection of cold chain food, and researchers have also put forward effective prevention and control suggestions for problems in international logistics and transportation.

In 2022, the keywords focused on “#6 normalization”. Active surveillance of key population groups was an effective way to detect the epidemic as early as possible after the routine prevention and control stage. By optimizing data analysis and strengthening risk assessment of the imported epidemic, researchers could accurately adjust prevention and control measures. In the post-epidemic era, the question of how to meet the requirements of emergency working mechanisms and balance the relationship between emergency health quarantine and normal working mode must be studied and investigated by researchers.

The keyword cluster analysis based on the literature of the WOS core set showed that six clusters were formed by the keywords, among which the two clusters of “#1 infectious disease” and “#2 COVID-19” had a better clustering effect, with the module value Q=0.7196 and the average contour value S=0.9330 (Figure S5).

In this study, the bibliometrics method was adopted to analyze the hot spots and frontiers of COVID-19 prevention and control measures in Chinese ports during 2020-2022 by searching relevant literature from the Wanfang, CNKI, and CQVIP databases, along with the WOS core. The results showed that some research institutions, and researchers pointed out the direction for port epidemic prevention and control in the post-epidemic period using aspects of prevention and control measures, precise policy implementation, joint prevention and control, risk assessment, and biosecurity.

The COVID-19 epidemic has been a once-in-a-century public health emergency. In 2020, a total of 75 articles (46.01%) related to port epidemic prevention and control were retrieved from the Wanfang, CNKI, and CQVIP databases. The abundant literature in the early stage of the epidemic provided scientific guidance and implementation norms for epidemic prevention and control at the port. A total of 45 articles were retrieved from the Wanfang, CNKI, and CQVIP databases and WOS core set in 2021, and 34 articles were retrieved from the 4 databases from January to September 2022, indicating that the number of published studies decreased and became more consistent after the COVID-19 epidemic became relatively stable. Through the analysis of the cooperation network map of researchers and institutions, it was found that there was less cross-regional cooperation among research institutions in the Wanfang, CNKI, and CQVIP database, and relatively stable cooperation groups had not been formed among the researchers, indicating that Chinese scholars in this field need to take note of cross-regional academic exchanges and cooperation. The institutions engaged in the research were relatively concentrated, with the institute of Inspection and Quarantine Science and Customs as the main research force. Han Hui's team at CAIQ published the most articles, followed by Sun Xiaodong's team at Beijing Customs. They formed a scientific research cooperation network and made more contributions to the risk assessment of COVID-19 in China. Beijing Customs and other institutions relied on port health and quarantine work to obtain more on-the-spot data, which resulted in certain advantages in carrying out a risk assessment of imported COVID-19 cases. In the WOS core set, researchers and research institutions formed a certain scale of cooperation networks. Although researchers published few papers, four large-scale cooperation networks had been formed, and research institutions such as Fudan University also had two large-scale cooperation networks. This suggested that Chinese researchers paid more attention to academic exchanges and teamwork when publishing in foreign journals, and multi-departmental cooperative research achieved preliminary results.

The port is the frontline of “preventing the import from outside” (Jingru 2021). The key word analysis of the collinear network graph showed that the content and fields involved in the prevention and control measures of COVID-19 at ports were relatively limited, mainly focusing on “COVID-19”, “epidemic prevention and control”, “health quarantine”, and “port”. “COVID-19”, “epidemic prevention and control”, “health quarantine”, “risk assessment” and “public health emergencies” were ongoing research hotspots. “Overseas import” indicated that trade and population mobility have brought an increased risk of imported COVID-19 infection. In addition, extended research has been conducted on big data community, risk classification, biosafety, virus variation, and gene sequencing, providing a regular guarantee for epidemic prevention and control in the post-epidemic period.

Cluster analysis showed that the high-frequency keywords in the Wanfang, CNKI, and CQVIP databases were mainly concentrated in “#0 COVID-19”, “#1 risk assessment”, “#2 prevention and control mechanism”, “#3 infectious diseases”, and “#4 public health”. The keywords with good clustering effect in the WOS core cluster were “#1 infectious diseases” and “#2 COVID-19”. In 2020, the Chinese “port joint prevention and control mechanism closed-loop management model” achieved remarkable results in the detection and management of imported cases (Fang Qiwen, Gong Xiaohuan et al. 2020). The nucleic acid detection information management system plays the role of “big data” analysis in large-scale nucleic acid screening and mobile sampling, providing accurate data for epidemic prevention and control (Wang Zhihong, Mo Hongmei et al. 2021). At the same time, “customs” and other institutions made scientific arrangements for epidemic prevention and control, accurately implemented health and quarantine policies, and strictly prevented the importation of overseas epidemic diseases through water transport ports (Junhui 2020). Land ports carried out “driving on behalf” to guarantee port cargo transportation, standardized quarantine management of entry personnel, and achieve “people are under control and goods are released” to prevent the importation of COVID-19 through land ports (Zhang Meiling, Fu Xiaoqing et al. 2022). Combined with the intelligence analysis of big data on infectious diseases, researchers continued to explore the supervision mechanism of safety and epidemic prevention at border ports and made responses to varying degrees according to the epidemic situation of virus variants, the nature and severity of public health events at border ports (An 2020).

Preventing imported cases was the main task of epidemic prevention and control in China in 2021. Chinese epidemic prevention policy at that time could have well controlled the development of the epidemic situation. For the port with a large population imported from epidemic areas, effective screening and necessary isolation were important means to prevent the continuation of imported cases (Jiwei Jia, Siyu Liu et al. 2021). Some scholars studied and assessed the risk level of imported COVID-19 by using expert consultation and risk matrix methods, which provided targeted suggestions for the prevention and control of imported COVID-19 at ports (Han Hui, Wu Bo et al. 2021). Meanwhile, in order to reduce the risk of the novel coronavirus entering the country through imported cold chain food, the Ministry of Transport explicitly required comprehensive disinfection of the transportation and packaging of imported cold chain food. Researchers also put forward some effective suggestions for the problems existing in international cold food chain logistics (Chang Yutong, Liu Lijuan et al. 2021). They have made many contributions in the process of constantly exploring COVID-19 prevention and management strategies at airports and seaports, in order to achieve the best prevention and control effect with the most accurate and effective management strategies (Zhang Yi, Sun XiaoDong et al. 2022).

In 2022, COVID-19 was still prevalent all over the world, and the Chinese epidemic prevention policy at that time could have well controlled the spread of the epidemic situation. Epidemic prevention and control had been under the pressure to “prevent the external import and internal diffusion” for a long time. After entering the normal phase of prevention and control, active monitoring of key populations was an effective way to detect the epidemic early (Yan, Jianpeng et al. 2022). By taking a series of comprehensive prevention and control measures, such as large-scale nucleic acid screening, tracing and isolating close contacts and strict travel management, most local epidemics were controlled quickly and effectively, accumulating valuable experience for epidemic prevention and control (Yan, Jianpeng et al. 2022). Researchers optimized data analysis, strengthened the construction of the risk governance community, and created a new mode of port control for entry and exit management to deal with the entry of foreigners in the post-epidemic era (Weiran and Qiang 2022). With the change in epidemic prevention and control, in the post-epidemic era, researchers have conducted further research and reflections on how to adapt health quarantine work to the requirements of emergency and normalization, and how to balance the relationship between emergency and normalization work modes of health quarantine, so as to strengthen the capacity building of health quarantine and meet the needs of safeguarding national security (Qiang 2022).

In this study, CiteSpace software was used to draw a visualization map of researchers' cooperation network, research institution network, keyword collinear network, and keyword cluster analysis, and a preliminary analysis was made on the map, reflecting the hot spots and research trends in the process of solutions at Chinese ports. There may be some errors due to subjective factors when removing irrelevant papers manually. In addition, the number of papers contained in the WOS core set was relatively small, so further collection and analysis are needed to make it more representative. Considering the comprehensive and authoritative literature of the Wanfang, CNKI, CQVIP database, and the WOS core set, this study can be considered to present the main scientific research forces, research frontiers, and hot spots in this field in the last three years. It also represents a good reference value for the prevention and control measures of COVID-19 in Chinese ports.

Although China has achieved a phased victory in the fight against COVID-19, the epidemic is not over yet (Zeng Wenge and Yue 2022). In the post-epidemic period, it is important to strengthen the management of solutions at the port. We hope to strengthen cooperation between research institutions and scholars, and strengthen the early warning risk and voluntary disclosure of passenger health (2022) based on epidemiological investigation at ports, so as to identify high-risk passengers in advance. This will provide a strong reference for on-site customs officers to implement precision quarantine, and provide scientific guidance and technical support in order “prevent import from the outside".

CiteSpace software displayed the research hotspots of COVID-19 solutions at domestic ports in the form of an atlas, which was in line with the characteristics of current prevention and control work. In the post-epidemic period, epidemic management at ports should be strengthened and targeted epidemic prevention should be maintained.

Authors' contributions

Fei He designed the study. Chunyan Huang performed the analysis. Yuanming Qiu and Yiliang Fang contributed to interpretation of the results. Guangmin Chen checked the data. Chunyan Huang, Yuanming Qiu and Jianfeng Xie drafted the manuscript. Zhijian Hu and Kuicheng Zheng contributed to critical revision of the manuscript for important intellectual content. Fei He and Xinying Xuapproved the final version of the manuscript. All authors approved the submitted version.

Funding

This study was supported by The Major Health Research Project of Fujian Province (No. 2021ZD01001).

Data availability

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval Not applicable.

Consent to participate Not applicable.

Consent for publication All authors agreed to publish.

Conflict of interest The authors declare no competing interests.

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Table 1 Top 10 researchers and institutions on prevention and control measures of the COVID-19 epidemic

Sort	Researchers		Institutions
Sort	Names	Number	Names	Number	Study subjects
1	Han Hui	8	Chinese Academy of Inspection and Quarantine	10	SARS-CoV-2; Port; Risk assessment
2	Sun Xiaodong	6	Beijing Customs District P.R.CHINA	6	COVID-19; Input; Health quarantine
3	Jia Jiaojiao	6	Dalian Maritime University	5	Cruise based outbreaks; Outbreak control; Hygiene measures
4	Wu Bo	6	General Administration of Customs (Beijing) International Travel Healthcare Center	4	COVID-19; Input; Risk assessment
5	Ju Chengfei	4	Rongcheng Customs District P.R.CHINA	4	COVID-19; Crew; Seaport
6	Tian Rui	4	China People's Police University	3	entry; Risk prevention and control; Post epidemic Era
7	Liu Yi	4	Beijing Emergency Medical Center	3	Public health emergencies; Prehospital emergency; transport
8	Zhang Yi	4	People's Public Security University of China	3	Health quarantine; Border ports
9	Song Yajing	4	Qingdao Customs District P.R.CHINA	3	COVID-19; Outbreak control; Health quarantine
10	Liu Lijuan	4	Fujian Provincial Center for Disease Control and Prevention	2	SARS-CoV-2; Delta variants; Imported cases

Table 2 Keywords clustering results of research on prevention and control measures for new coronal pneumonia in Chinese ports on Wanfang database, CNKI, CQVIP database

Cluster	Size	Silhouette	Mean	Top terms (LLR)
#0	16	1.000	2020	COVID-19; Central European column; health quarantine; customs; outbreak control
#1	13	0.948	2021	Risk assessment; risk assessment; input; port site; mutans; epidemiology
#2	10	0.938	2020	Prevention and control mechanisms; COVID-19; health quarantine; impacts and countermeasures; entry
#3	10	0.900	2020	Infectious diseases; super communicators; big data; situational analysis; intelligence
#4	6	0.894	2021	Public health; new crown pneumonia outbreak; population movements; crisis management; international co-operation
#5	4	0.991	2021	Department of transportation; road ports; partition grading; airport; international logistic transport
#6	4	0.911	2022	Standardization; meet an emergency; working mechanism; migration management; health quarantine

Visual analysis of the prevention and control measures of COVID-19 in Chinese ports

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