ResearchArticle Investigation of the First African Swine Fever Outbreak in a Domestic Pig Farm in Hong Kong YunYoungGo , 1 JeremyH.P.Ho , 2 KarinaW.S.Tam, 2 Maedeh Kamali, 3 Yiwen Zhang, 1 Candy C. Y. Lau, 2 Song Hao Li, 3 Michael T. Wilson , 3 Zhihao Guo , 1 Runsheng Li , 1 Guoqian Gu , 1 May P. Y. Tse, 4 Fraser I. Hill, 4 Carrie Batten, 5 Amanda Corla, 5 John Flannery, 5 Anne Conan, 3 Christopher J. Brackman , 2 and Dirk U. Pfeifer 1,3 1 Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, CityUniversityofHongKong,HongKongSAR,China 2 Agriculture, Fisheries and Conservation Department, Government of the Hong Kong Special Administrative Region, HongKongSAR,China 3 CentreforAppliedOneHealthResearchandPolicyAdvice,CityUniversityofHongKong,HongKongSAR,China 4 CityU Veterinary Diagnostic Laboratory, City University of Hong Kong, Hong Kong SAR, China 5 Te Pirbright Institute, Ash Road, Woking, Surrey, UK Correspondence should be addressed to Yun Young Go; yunygo@cityu.edu.hk Received 26 October 2022; Revised 27 April 2023; Accepted 5 May 2023; Published 18 May 2023 Academic Editor: Lin•Zhu Ren Copyright©2023YunYoungGoetal.TisisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Inthisstudy,wedescribetheepidemiologicalinvestigationofthe frstAfricanswinefever(ASF)outbreakinalocaldomesticpig farmintheNewTerritoriesofHongKongin2021.Intheoutbreakfarm,severalafectedpigspresentedclinicalandpathological signs consistent with ASF, while the remaining pigs showed nonspecifc clinical signs or did not exhibit any clinical signs. Te relative low morbidity and mortality of ASF on this farm resulted in delayed detection and implementation of the control response.Despitethisdelay,nofurtherspreadofthediseasefromthisfarmtootherfarmsorwildboarswasobserved.Teclinical presentationofASFintermsofmorbidityandmortalityonthisfarmindicatedthatitisessentialforefectivesurveillanceaimedat early detection for farmers, veterinarians, and pathologists to be educated about the diferent ways ASF can express itself in domestic pig populations. Epidemiological investigations consisted of feld inspection, interviews with farm personnel to assess the management and biosecurity practices within the farm, and laboratory testing of animal and environmental samples. In addition,thecompletegenomeofASFVwasobtaineddirectlyfromthetissuesofaninfectedpigtofacilitatetheepidemiological investigation. Te genetic relationship at the whole genome level indicated that the isolate shared the highest level of similarity withgenotypeIIASFVs,includinga2019isolatefromGuangdongprovince,China(GD2019).Overall,theinformationpresented herefromtheon•farminvestigationwiththatfromdiagnostictestingandmolecularanalysesprovidesabasisforinformedactions topreventfutureincidentsinfarmswithsimilarcharacteristics.Furthermore,thisstudyhighlightedtheneedtoincreasecurrent knowledge about the molecular diversity amongst circulating viruses and potentially trace the source of infection. 1. Introduction Africanswinefever(ASF)isacontagioushemorrhagicviral disease afecting domestic pigs and wild boars [1]. Te diseaseiscausedbyAfricanswinefevervirus(ASFV),andit isonthelistofnotifablediseasesoftheWorldOrganisation for Animal Health (WOAH) due to its high mortality rate and signifcant socioeconomic impact on pork production and trade in afected countries [2–5]. Morbidity and mor• tality for ASF can reach up to 100% in na¨ ıve domestic pig populations[6].Teclinicalsignscanvaryinseverity,from acute to chronic disease, depending on the complex in• teractionsbetweenvirusandhostfactors.Peracuteandacute presentations are the most common forms of the disease, Hindawi Transboundary and Emerging Diseases Volume 2023, Article ID 1720474, 15 pages https://doi.org/10.1155/2023/1720474