[Ophthalmologic Sentinel Surveillance Results, 2013-2022]

Korea Disease Control and Prevention Agency has been operating an Ophthalmologic Sentinel Surveillance System since August 2003 to monitor the epidemic of epidemic keratoconjunctivitis (EKC) and acute hemorrhagic conjunctivitis (AHC), both of which are highly contagious eye diseases. From 36 weeks in 2013 to 53 weeks in 2022, the surveillance results showed a significant decrease in the average annual number of suspected cases of EKC, from 22.5 cases per 1,000 outpatients in 2018 to 4.0 in 2022. In particular, EKC showed a seasonal increase during the summer, peaking in August and September. Despite a significant decrease in suspected cases from 2020 to 2022, the seasonal epidemic pattern remained similar to previous years. Furthermore, the peak rate has decreased each year since 2016 (49.7 cases), but increased again in 2022 (9.0 cases). Contrastingly, suspected cases of AHC remained consistently low compared to EKC, without any seasonal epidemic pattern. Both diseases were most reported in the age group 0-6 years, with a significant decrease observed in all age groups after 2020, maintaining lower levels compared to pre-coronavirus disease 2019 (COVID-19) years. This decline is likely attributed to the implementation of COVID-19 control measures such as social distancing. However, as COVID-19-related measures have been gradually lifted, it is anticipated that the occurrence will gradually increase to pre-pandemic levels, emphasizing the importance of continuous monitoring.