Pathogenetic identification and genetic characteristics of an acute hemorrhagic conjunctivitis outbreak
- Author:
LI Minjie
;
CHEN Qingliang
;
CHI Jing
- Publication Type:Journal Article
- Keywords:
Acute hemorrhagic conjunctivitis;
Coxsackievirus A24 variant;
aggregated outbreak;
evolutionary analysis
- From:
China Tropical Medicine
2024;24(6):702-
- CountryChina
- Language:Chinese
-
Abstract:
Abstract： Objective To identify the pathogenetic characteristics of an aggregated outbreak of acute hemorrhagic conjunctivitis in a school in Bao'an District, Shenzhen in 2023, and to analyze its virological characteristics, providing a reference and basis for the rapid tracing of the source of infection and the handling of such outbreaks. Methods A total of 22 eye swab samples were collected from an AHC cluster in a school in Bao'an District, Shenzhen in 2023. Real-time fluorescence quantitative polymerase chain reaction(PCR) method was used to detect Enterovirus 70 (EV70) and Coxsackievirus A24 (CVA24) viruses in eye swab specimens collected from patients. The positive samples were performed by full sequencing of the viral gene (VP1 nucleotide). The sequenced data was compared with that from different periods and regions for CVA24, analyzing homologies and constructing a phylogenetic tree. Additionally, the nucleotide sequences were translated into amino acid sequences to analyze mutations at the amino acid sites. Results Among the 22 eye swab specimens collected, 16 samples were positive for CVA24 virus as determined by fluorescence quantitative PCR, with a positive rate of 72.73%, while all samples tested negative for EV70. VP1 primers were used to amplify 16 positive specimens, successfully sequencing the complete VP1 sequence from 14 samples. They were determined to be of the CVA24v GⅣ genotype. The genetic evolutionary analysis showed that the 14 CVA24v nucleotide sequences had 100.00% homology with each other, 85.14% homology with the prototype strain EH24/70 of CVA24v, and 77.27% homology with the prototype strain Joseph of CVA24. The phylogenetic tree showed that these isolates and the CVA24v strains circulating in Zhongshan City, Guangdong Province at the same time were on the same evolutionary clade, suggesting a close phylogenetic relationship. Compared with the amino acid sequence of the reference sequence before 2023, the amino acid sequence of the VP1 region of this epidemic strain formed a new mutation at the 16th site, with a substitution from leucine (L) to isoleucine (I). Conclusions The pathogen causing this outbreak of acute hemorrhagic conjunctivitis was the Coxsackievirus A24 variant, presenting a new variant site appears in its amino acid sequence. According to the results of the phylogenetic tree, the strain is presumed to originate from a strain circulating in Guangdong Province during the same period.
- Full text:202506181022075539512.Pathogenetic identification and genetic characteristics of an acute hemorrhagic conjunctivitis outbreak.pdf
