Introduction: The rapid production of a large volume of literature during the last 2-3 phases of the Covid-19 disease outbreak created a substantial burden for clinicians and scientists. Therefore, this paper provides a bibliometric overview on the high-cited papers indexed in the ESI database in the field of Covid-19, during 2020-21, focusing on the research domain and keywords, main actors (countries, organizations and authors) and main sources of publications. Methods: The Essential Science Indicators (ESI) database is widely used to assess scientific outputs. ESI include highcited papers that have received enough citations to place them in the top 1% when compared to all other papers published in the same year in the same field. High-cited papers are defined as papers receiving 100 or more citations since their publication. Therefore, high-cited papers included in ESI database are of high-quality in each field and therefore used in this study. A bibliometric analysis based on 848 high-cited papers extracted from the Essential Science Indicators database was carried out to provide insights into performances and research characteristics of Covid-19 literature. Indicators were applied to evaluate the influence of the most productive journals, countries/territories, organizations and authors. Social network analysis was performed to evaluate and visualize the interaction among productive countries/territories, organizations, authors and keywords using VOSviewer software. Results: The results showed that the 848 high-cited papers received 244699 citations were from 9734 authors employed at 2607 organizations based in 101 countries/territories. The papers were published in 369 journals in the field. The top 5 core journals ranked based on: (i) total papers were New England Journal of Medicine (37), Science of the Total Environment (35), Science (28), The Lancet (21) and Nature (18) and (ii) total citations were New England Journal of Medicine (28173), Lancet (17128), JAMA-Journal of the American Medical Association (9603), International Journal of Antimicrobial Agents (5865) and Nature Medicine (5659). The top 5 organizations ranked on (i) total papers were Huazhong University of Science & Technology (42), Harvard Medical School, USA (41), University of Oxford, U.K. (31), University of Cambridge, U.K. (25) and London Global University (UCL)(25) and (ii) total citations were Huazhong University of Science & Technology, China (32563), University of Hong Kong (17868), Tsinghua University, China (15827), University of Oxford (13802) and Guanzhou Medical University, China (13155). The top 5 authors ranked on: (i) total papers were Y. Zhang (15), Y. Hu (14), L. Liu (14), J,. Wang (14) and Y. Liu (13) and (ii) total citations were Y. Liu (23285), J. Xiang (.20391), Y. Hu (18804) and Y. Zhang (16495). The top five countries ranked on : (I) total papers were USA (336), China (222), U.K. (153), Italy (90) and Germany (74) and (ii) total citations were China (114620), USA (88474), U.K. (46535), Italy (24546) and Germany (24028).Based on network map using VOSviewer, there were micro, meso and macro level collaborations based on common interests in a specific topic. Analysis of all keywords showed that the research was distributed into 6 clusters. Conclusion: Results obtained from this study can provide valuable information for researchers to better identify present and future hotspots in Covid-19-related fields. The most relevant literature on the Covid-19 pandemic will also provide information relevant to the evidence-based decision-making process and future studies are essential to gain precise knowledge on Covid-19 infection across various human organs and various sub-fields and sectors.
Key words: Covid-19, High-Cited Papers, ESI, Global Papers, Bibliometrics, Scientometrics.
