Introduction:In late August 2025,a locally transmitted CHIKF outbreak was detected in Licheng District,Quanzhou City,Fujian Province.On September 3,2025,two locally acquired cases without travel history to Licheng Dis...Introduction:In late August 2025,a locally transmitted CHIKF outbreak was detected in Licheng District,Quanzhou City,Fujian Province.On September 3,2025,two locally acquired cases without travel history to Licheng District were reported in the adjacent Nan’an City,Quanzhou City.This study aimed to identify the infection source of the local chikungunya cases in Nan’an City.Methods:Field epidemiological investigations were conducted to collect case-related information and trace the infection source.Aedes mosquito density was monitored in the core epidemic area.Whole-genome amplification and sequencing were performed on chikungunya virus(CHIKV)in the serum samples of the cases.The obtained sequences were aligned with those from GenBank,and a phylogenetic tree was constructed for viral genotypic analysis.Results:Nine days before the onset of the two local cases,an imported chikungunya case from Licheng District had received treatment at Clinic E near their residential area.Whole-genome sequencing revealed complete identity among the CHIKV strains from the two local cases and the one imported case,all belonging to the ECSA genotype.Conclusion:Epidemiological link between the locally acquired CHIKF cases in Nan’an City,Quanzhou and the imported case from Licheng District,Quanzhou.In a previously CHIKV-free nonendemic area with Aedes mosquitoes,secondary local cases may emerge approximately 9 days after the introduction of imported viremic cases.展开更多
基金Supported by the Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare(No.[2023]2839)the Technology Major Project for the Prevention and Control of Emerging,Sudden,and Major Infectious Diseases(2026ZD01908800).
文摘Introduction:In late August 2025,a locally transmitted CHIKF outbreak was detected in Licheng District,Quanzhou City,Fujian Province.On September 3,2025,two locally acquired cases without travel history to Licheng District were reported in the adjacent Nan’an City,Quanzhou City.This study aimed to identify the infection source of the local chikungunya cases in Nan’an City.Methods:Field epidemiological investigations were conducted to collect case-related information and trace the infection source.Aedes mosquito density was monitored in the core epidemic area.Whole-genome amplification and sequencing were performed on chikungunya virus(CHIKV)in the serum samples of the cases.The obtained sequences were aligned with those from GenBank,and a phylogenetic tree was constructed for viral genotypic analysis.Results:Nine days before the onset of the two local cases,an imported chikungunya case from Licheng District had received treatment at Clinic E near their residential area.Whole-genome sequencing revealed complete identity among the CHIKV strains from the two local cases and the one imported case,all belonging to the ECSA genotype.Conclusion:Epidemiological link between the locally acquired CHIKF cases in Nan’an City,Quanzhou and the imported case from Licheng District,Quanzhou.In a previously CHIKV-free nonendemic area with Aedes mosquitoes,secondary local cases may emerge approximately 9 days after the introduction of imported viremic cases.
