Status of Vector Surveillance for Infectious Diseases in Quarantine Areas at International Points of Entry, 2025

This study aims to prevent the introduction and establishment of overseas-origin infectious disease vectors associated with climate change and increasing international travel and trade by assessing the current status of vector surveillance at international points of entry in the Republic of Korea (ROK).

Mosquito surveillance was conducted at 40 major international airports and seaports in the ROK across 16 collection cycles from March to November 2025. Adult mosquitoes were collected using Biogents (BG)-Sentinel traps, light-emitting diode (LED) black-light traps, and Gravid traps. All specimens were morphologically identified to the species level and subsequently screened for six major viral pathogens using multiplex real-time reverse transcription polymerase chain reaction.

A total of 37,544 mosquitoes representing 18 species were collected during the surveillance period. Although the overall mosquito population decreased by 21.6% compared with the previous year, species diversity increased by the detection of three additional species. Culex pipiens was the dominant species, accounting for 64.4% of all collected specimens, with its peak annual density observed in September (28.8%). Regional analysis showed that the highest Trap Index (T.I.) was recorded in the Capital region (104.6), whereas species richness was greatest in Gyeongnam Province (15 species). With respect to trapping efficiency, the BG-Sentinel trap (T.I.=75) demonstrated a significantly higher capture performance the than LED black-light traps. None of the mosquito samples tested positive for any of the six targeted viral pathogens.

The observed increase in mosquito species diversity at airports suggests a higher risk of invasive vector introduction through air travel. Accordingly, differentiated surveillance strategies are required: seaports should prioritize monitoring population density trends, whereas airports should focus on the early of invasive mosquito species at points of entry, thereby strengthening national preparedness against the spread of vector-borne diseases.