Pathogen surveillance of acute conjunctivitis reveals recent emergence of coxsackievirus A24 variants and high genotypic diversity of human adenoviruses in Shenzhen, China, 2018-2024.

OBJECTIVES

To investigate the etiological characteristics of acute conjunctivitis in Shenzhen, China.

METHODS

A total of 1234 conjunctival swabs collected between 2018 and 2024 were examined for coxsackievirus A24 variant (CVA24v), enterovirus D70 (EV-D70) and human adenovirus (HAdV). Complete VP1 sequences of CVA24v strains were determined and analyzed. HAdV was genotyped by PCR methods targeting the three genes (penton base, hexon and fiber) and sequencing. SPSS 22.0 software was used for statistical analysis.

RESULTS

CVA24v was first detected in 2023, with a detection rate of 33.3 % (63/189). No EV-D70 was detected in 2018-2024. The annual distributions of HAdV-infected patients were 52.6 % (101/192), 62.7 % (111/177), 21.1 % (37/175), 9.0 % (14/155), 10.5 % (17/162), 15.9 % (30/189) and 21.7 % (40/184), respectively. CVA24v strains from this study clustered in a clade with significant temporal aggregation characteristic within the genotype GIV. Eight amino acid variation sites (T11A, I16L, K20I, L32P, K105R, A146T, R277G and P280S) were observed in VP1 sequences of CVA24v strains from this study when compared to the close strains. Conjunctivitis patients with one of the three symptoms (weakness, fever and blurred vision) had a higher detection rate of HAdV. Eleven known HAdV genotypes (HAdV-B3, -B14, -B21, HAdV-D8, -D37, -D42, -D53, -D64, -D85, -D115 and HAdV-E4) and 7 unknown genotypes were detected in 2020-2024, with HAdV-D37 (30.9 %), HAdV-D115 (21.1 %) and HAdV-B3 (17.1 %) being the three predominant genotypes.

CONCLUSIONS

The unique genetic characteristics were observed in Shenzhen CVA24v strains. HAdVs associated with conjunctivitis exhibited a high degree of genotypic diversity in Shenzhen, and HAdV-D115 related to conjunctivitis was first reported in this study.