The number of malaria patients spiked this year, likely due to an increase in people's outdoor activities amid a lifting of social distancing regulations.

According to the Korea Disease Control and Prevention Agency(KDCA) on Tuesday, there were 349 reported cases of the mosquito-borne infectious disease between January and September this year, up 27-point-eight percent on-year.

The January-to-September tally is 55 higher compared to the 294 reported cases last year.

Authorities have cited climate change, as well as the lifting of social distancing as factors that led to the hike in infections.

Between 2017 and 2019, prior to the COVID-19 outbreak, annual cases of malaria ranged in the 500s. The figure markedly dropped to 385 in 2020 and 294 in 2021 following the enforcement of pandemic-triggered social distancing.