摘要
Introduction:On September 11,2024,a school in the Beijing Economic and Technological Development Area(Jingkai area)reported multiple cases of fever.Public health professionals from the local CDC promptly initiated an on-site epidemiological investigation.Methods:We conducted an initial epidemiological assessment and rapidly identified the index case.Simultaneously,we performed active case finding throughout the school.Throat swab samples were collected from symptomatic individuals and submitted to the laboratory for pathogen testing.Real-time RTPCR was used to screen for a comprehensive panel of respiratory pathogens.We established viral cultures and performed PCR to amplify target gene sequences.Molecular characterization was conducted using gene homology analysis and phylogenetic reconstruction.Results:Active case finding identified 15 fever cases(37.8℃-39.9℃),all from two adjacent classes in the school.Case onset was concentrated between September 9 and 11,with 6 males and 9 females,all aged 6 years.Fourteen throat swab samples were collected,with 10 testing positive for HAdV genes.Six viral strains were successfully isolated through cell culture.Sequence analysis revealed 100% gene homology in the hexon Loop2 region,consistent with HAdV-B3.Furthermore,the penton base gene,hexon gene,and fiber gene of all 6 strains exhibited 100% homology.The penton base gene showed 99.2% homology with the HAdV-B7 reference strain,while the hexon and fiber genes demonstrated 99% and 96.8% homology,respectively,with the HAdV-B3 reference strain.The genotype of all 6 strains was P7H3F3,consistent with the HAdV-B114(P7H3F3)genotype,confirming their identification as HAdVB114.Conclusions:This outbreak was caused by a novel recombinant human adenovirus,HAdV-B114.Given the potential for such emerging HAdV strains to trigger infectious disease outbreaks,enhanced surveillance systems and comprehensive molecular characterization are essential for early detection and effective public health response.
