{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T16:26:53Z","timestamp":1784824013541,"version":"3.55.0"},"reference-count":39,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,12,9]],"date-time":"2022-12-09T00:00:00Z","timestamp":1670544000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>In May 2021, the SARS-CoV-2 Delta variant led to the first local outbreak in China in Guangzhou City. We explored the epidemiological characteristics and spatial-temporal clustering of this outbreak.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Based on the 153 cases in the SARS-CoV-2 Delta variant outbreak, the Knox test was used to analyze the spatial-temporal clustering of the outbreak. We further explored the spatial-temporal clustering by gender and age groups, as well as compared the changes of clustering strength (S) value between the two outbreaks in Guangzhou.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The result of the Knox analysis showed that the areas at short distances and brief periods presented a relatively high risk. The strength of clustering of male-male pairs was higher. Age groups showed that clustering was concentrated in cases aged \u2264 18 years matched to 18\u201359 years and cases aged 60+ years. The strength of clustering of the outbreak declined after the implementation of public health measures. The change of strength of clustering at time intervals of 1\u20135 days decreased greater in 2021 (S = 129.19, change rate 38.87%) than that in 2020 (S = 83.81, change rate 30.02%).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>The outbreak of SARS-CoV-2 Delta VOC in Guangzhou has obvious spatial-temporal clustering. The timely intervention measures are essential role to contain this outbreak of high transmission.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fpubh.2022.1050096","type":"journal-article","created":{"date-parts":[[2022,12,9]],"date-time":"2022-12-09T08:44:04Z","timestamp":1670575444000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Spatial-temporal clustering of an outbreak of SARS-CoV-2 Delta VOC in Guangzhou, China in 2021"],"prefix":"10.3389","volume":"10","author":[{"given":"Qian","family":"Zhang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meng","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianxiong","family":"Hu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guanhao","family":"He","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuguang","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yali","family":"Zhuang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zuhua","family":"Rong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lihua","family":"Yin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianguo","family":"Zhao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zitong","family":"Huang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weilin","family":"Zeng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xing","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhihua","family":"Zhu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yerong","family":"Tang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Quan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihan","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Di","family":"Fu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianpeng","family":"Xiao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,12,9]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"101129","DOI":"10.1016\/j.eclinm.2021.101129","article-title":"Transmission, viral kinetics and clinical characteristics of the emergent SARS-CoV-2 Delta VOC in Guangzhou, China","volume":"40","author":"Wang","year":"2021","journal-title":"EClinicalMedicine."},{"key":"B2","unstructured":"Update on SARS-CoV-2 Variant Nomenclature"},{"key":"B3","unstructured":"Technical Advisory Group on Virus Evolution. Update on Omicron"},{"key":"B4","doi-asserted-by":"publisher","first-page":"1125","DOI":"10.1111\/jdi.13605","article-title":"The COVID-19 world - Are we there yet?","volume":"12","author":"Hamamoto","year":"2021","journal-title":"J Diabetes Investig."},{"key":"B5","unstructured":"Weekly epidemiological update on COVID-192021"},{"key":"B6","doi-asserted-by":"publisher","first-page":"6551","DOI":"10.1002\/jmv.27210","article-title":"SARS-CoV-2 B1617 Indian variants: are electrostatic potential changes responsible for a higher transmission rate?","volume":"93","author":"Pascarella","year":"2021","journal-title":"J Med Virol."},{"key":"B7","unstructured":""},{"key":"B8","doi-asserted-by":"publisher","first-page":"410","DOI":"10.1038\/s41586-020-2293-x","article-title":"Effect of non-pharmaceutical interventions to contain COVID-19 in China","volume":"585","author":"Lai","year":"2020","journal-title":"Nature."},{"key":"B9","doi-asserted-by":"publisher","first-page":"2045","DOI":"10.1093\/cid\/ciaa422","article-title":"Population movement, city closure in Wuhan, and geographical expansion of the COVID-19 infection in China in January 2020","volume":"71","author":"Liu","year":"2020","journal-title":"Clin Infect Dis."},{"key":"B10","doi-asserted-by":"publisher","first-page":"493","DOI":"10.1126\/science.abb4218","article-title":"The effect of human mobility and control measures on the COVID-19 epidemic in China","volume":"368","author":"Kraemer","year":"2020","journal-title":"Science."},{"key":"B11","doi-asserted-by":"publisher","first-page":"1","DOI":"10.2807\/1560-7917.ES.2022.27.10.2100815","article-title":"Transmission dynamics and epidemiological characteristics of SARS-CoV-2 Delta variant infections in Guangdong, China, May to June 2021","volume":"27","author":"Kang","year":"2022","journal-title":"Euro Surveill"},{"key":"B12","unstructured":"COVID-19 Situation Update in Guangzhou2021"},{"key":"B13","unstructured":"Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (Trial Version 8)2020"},{"key":"B14","unstructured":"COVID-19 Clinical Management: Living Guidance2021"},{"key":"B15","doi-asserted-by":"publisher","first-page":"1935","DOI":"10.1002\/(SICI)1097-0258(19960930)15:18<1935::AID-SIM406>3.0.CO;2-I","article-title":"A k nearest neighbour test for space-time interaction","volume":"15","author":"Jacquez","year":"1996","journal-title":"Stat Med"},{"key":"B16","doi-asserted-by":"publisher","first-page":"25","DOI":"10.2307\/2985220","article-title":"The detection of space-time interactions","volume":"1964","author":"Knox","year":"1964","journal-title":"Series C Appl Stat."},{"key":"B17","doi-asserted-by":"publisher","first-page":"2302","DOI":"10.1080\/13658816.2016.1174867","article-title":"spatial-temporal analysis of crime by developing a method to detect critical distances for the Knox test","volume":"30","author":"Kalantari","year":"2016","journal-title":"Int J Geogr Inf Sci."},{"key":"B18","doi-asserted-by":"crossref","DOI":"10.1002\/0471662682","volume-title":"Applied Spatial Statistics for Public Health Data","author":"Waller","year":"2004"},{"key":"B19","volume-title":"Statistical Methods in Spatial Epidemiology","author":"Lawson","year":"2013"},{"key":"B20","first-page":"802","article-title":"Study on the appllcation of Knox method to temporal-spatial cluster for infectious disease","volume":"28","author":"Liu","year":"2007","journal-title":"Chin J Epidemiol."},{"key":"B21","doi-asserted-by":"publisher","first-page":"487","DOI":"10.1007\/s00477-007-0132-3","article-title":"An incremental Knox test for the determination of the serial interval between successive cases of an infectious disease","volume":"21","author":"Jared","year":"2007","journal-title":"Stochast Environ Res Risk Assess."},{"key":"B22","doi-asserted-by":"publisher","first-page":"615","DOI":"10.3201\/eid1004.030186","article-title":"Dengue spatial and temporal patterns, French Guiana, 2001","volume":"10","author":"Tran","year":"2004","journal-title":"Emerg Infect Dis."},{"key":"B23","doi-asserted-by":"publisher","first-page":"91","DOI":"10.1016\/S0959-8049(98)00345-1","article-title":"Space-time clustering of acute lymphoblastic leukaemia in parts of the U.K. (1984-1993)","volume":"35","author":"Gilman","year":"1999","journal-title":"Eur J Cancer."},{"key":"B24","doi-asserted-by":"publisher","first-page":"1076","DOI":"10.1111\/j.1365-3156.2012.03040.x","article-title":"Space-time analysis of hospitalised dengue patients in rural Thailand reveals important temporal intervals in the pattern of dengue virus transmission","volume":"17","author":"Aldstadt","year":"2012","journal-title":"Trop Med Int Health."},{"key":"B25","first-page":"209","article-title":"The detection of disease clustering and a generalized regression approach","volume":"27","author":"Mantel","year":"1967","journal-title":"Cancer Res."},{"key":"B26","doi-asserted-by":"publisher","first-page":"74","DOI":"10.6040\/j.issn.1671-7554.0.2020.0745","article-title":"Epidemiological characteristics and spatial - temporal clustering of COVID-19 in Hebei Province","volume":"58","author":"Liu","year":"2020","journal-title":"J Shandong Univ."},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.11847\/zgggws1137165","article-title":"Spatial-temporal clustering of cases in a COVID-19 outbreak in Guangzhou city","author":"Zhang","year":"2022","journal-title":"Chin J Public Health."},{"key":"B28","doi-asserted-by":"publisher","first-page":"571","DOI":"10.1007\/s00180-007-0074-8","article-title":"Surveillance: an R package for the monitoring of infectious diseases","volume":"22","author":"H\u00f6hle","year":"2007","journal-title":"Comp Stat"},{"key":"B29","doi-asserted-by":"publisher","first-page":"1763","DOI":"10.3760\/cma.j.cn112338-20210613-00472","article-title":"Epidemiological characteristics of local outbreak of COVID-19 caused by SARS-CoV-2 delta variant in Liwan district, Guangzhou","volume":"42","author":"Li","year":"2021","journal-title":"Chin J Epidemiol."},{"key":"B30","doi-asserted-by":"publisher","first-page":"1","DOI":"10.2807\/1560-7917.ES.2021.26.24.2100509","article-title":"Increased transmissibility and global spread of SARS-CoV-2 variants of concern as at June 2021","volume":"26","author":"Campbell","year":"2021","journal-title":"Euro Surveill"},{"key":"B31","doi-asserted-by":"publisher","first-page":"1152","DOI":"10.11816\/cn.ni.2020-200269","article-title":"Epidemiological study of COVID-19 in Shanxi Province","volume":"30","author":"Li","year":"2020","journal-title":"Chin J Nosocomiol."},{"key":"B32","doi-asserted-by":"publisher","first-page":"1708","DOI":"10.1056\/NEJMoa2002032","article-title":"Clinical characteristics of coronavirus disease 2019 in China","volume":"382","author":"Guan WJ Ni","year":"2020","journal-title":"N Engl J Med."},{"key":"B33","doi-asserted-by":"publisher","first-page":"672","DOI":"10.1038\/s41591-020-0869-5","article-title":"Temporal dynamics in viral shedding and transmissibility of COVID-19","volume":"26","author":"He","year":"2020","journal-title":"Nat Med."},{"key":"B34","doi-asserted-by":"publisher","first-page":"1406","DOI":"10.1001\/jama.2020.2565","article-title":"Presumed asymptomatic carrier transmission of COVID-19","volume":"323","author":"Bai","year":"2020","journal-title":"JAMA."},{"key":"B35","doi-asserted-by":"publisher","first-page":"970","DOI":"10.1056\/NEJMc2001468","article-title":"Transmission of 2019-nCoV infection from an asymptomatic contact in Germany","volume":"382","author":"Rothe","year":"2020","journal-title":"N Engl J Med."},{"key":"B36","doi-asserted-by":"publisher","first-page":"n1445","DOI":"10.1136\/bmj.n1445","article-title":"Covid-19: Delta variant is now UK's most dominant strain and spreading through schools","volume":"373","author":"Torjesen","year":"2021","journal-title":"BMJ."},{"key":"B37","doi-asserted-by":"publisher","first-page":"579220","DOI":"10.3389\/fimmu.2020.579220","article-title":"mmunosenescence and inflammaging: risk factors of severe COVID-19 in older people","volume":"11","author":"Pietrobon","year":"2020","journal-title":"Front Immunol."},{"key":"B38","doi-asserted-by":"publisher","first-page":"1214","DOI":"10.3760\/cma.j.cn112338-20200303-00242","article-title":"Comparison of two epidemic patterns of COVID-19 and evaluation of prevention and control effectiveness: an analysis based on Guangzhou andWenzhou","volume":"41","author":"He","year":"2020","journal-title":"Chin J Epidemiol."},{"key":"B39","doi-asserted-by":"publisher","first-page":"584","DOI":"10.46234\/ccdcw2021.148","article-title":"transmission dynamics of an outbreak of the COVID-19 delta variant B.1.617.2 \u2014 Guangdong Province, China, May\u2013June 2021","volume":"3","author":"Zhang","year":"2022","journal-title":"China CDC Wkly"}],"container-title":["Frontiers in Public Health"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2022.1050096\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,9]],"date-time":"2022-12-09T08:44:14Z","timestamp":1670575454000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2022.1050096\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,9]]},"references-count":39,"alternative-id":["10.3389\/fpubh.2022.1050096"],"URL":"https:\/\/doi.org\/10.3389\/fpubh.2022.1050096","relation":{},"ISSN":["2296-2565"],"issn-type":[{"value":"2296-2565","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,9]]},"article-number":"1050096"}}