32 malaria cases reported in Seoul this year

1 in 5 patients last year fell ill in September–October

Disease-carrying mosquitoes found in 16 of Seoul's 25 districts

City runs mosquito forecast system, plans alerts through health app

With mosquito activity expected to rebound as the heat wave subsides, the Seoul Metropolitan Government has announced plans to strengthen surveillance of mosquito-borne diseases including malaria through the fall. [Herald DB]
With mosquito activity expected to rebound as the heat wave subsides, the Seoul Metropolitan Government has announced plans to strengthen surveillance of mosquito-borne diseases including malaria through the fall. [Herald DB]

Seoul has recorded more than 30 malaria cases this year, and city health officials are warning that the threat is far from over. With mosquito activity expected to rebound as temperatures ease following the summer heat wave, the Seoul Metropolitan Government said it will maintain heightened surveillance of malaria and other mosquito-borne diseases through the autumn months.

As of the end of last month, Seoul had logged 32 malaria cases this year, according to the Seoul Metropolitan Government and the Korea Disease Control and Prevention Agency. Cases in June and July — 8 and 10, respectively — accounted for 56.3 percent of the total, reflecting the peak summer transmission season.

Last year, Seoul recorded 70 malaria cases in total, with 45 cases, or 64.3 percent, concentrated in the summer months of June through August. Even so, 13 cases — 18.6 percent — emerged in September and October. A Seoul city official said residents should remain on guard against malaria even in the relatively cooler autumn.

Mosquito trap data collected by the city last year using digital mosquito monitoring systems illustrates the pattern: 62,351 mosquitoes were caught in June, 69,536 in July, 60,531 in August, 59,026 in September and 43,455 in October. While numbers declined after the summer peak, the figures show that mosquito activity remains substantial well into the fall.

The city operates a mosquito forecast system using 55 digital monitoring units installed across Seoul, providing residents with regular updates on mosquito activity. It also plans to distribute the information through "Sonmok Doctor 9988," a city-run mobile health management application, to make the alerts more accessible in daily life.

Disease-carrying mosquitoes were confirmed in 16 of Seoul's 25 districts — about 64 percent, or roughly two in every three districts — indicating a broad geographic spread across the city. Malaria-carrying mosquitoes were found in 14 districts, while dengue-carrying mosquitoes were detected in five.

Because the Seoul Metropolitan Government Institute of Health and Environment collects mosquitoes only at specific sites within each district, the possibility that these mosquitoes are present in all 25 districts cannot be ruled out. The city urged particular caution as recent drops in peak temperatures have allowed mosquito activity to pick up again after the heat wave.

An analysis of mosquito collection data for the fourth week of June — obtained by Seoul Metropolitan Council lawmaker Oh Geum-ran of the Democratic Party of Korea from the Seoul Metropolitan Government Institute of Health and Environment — found that both the Anopheles mosquito, which carries malaria, and the Asian tiger mosquito, which carries dengue fever, were caught in 16 of the city's 25 districts. The institute has been collecting mosquitoes every year since March.

A total of 41 Anopheles mosquitoes were caught. Yongsan-gu recorded the highest count with 10, followed by Songpa-gu with 5, Jungnang-gu and Gangdong-gu with 4 each, Guro-gu and Geumcheon-gu with 3 each, and Dobong-gu, Yangcheon-gu, Yeongdeungpo-gu and Gangnam-gu with 2 each. Jung-gu, Dongdaemun-gu, Gangbuk-gu and Gangseo-gu each yielded one.

Seven Asian tiger mosquitoes were collected in total. Gwangjin-gu had the highest count with 3, while Dobong-gu, Eunpyeong-gu, Yeongdeungpo-gu and Geumcheon-gu each recorded one.

The city urged residents to take personal precautions against mosquito bites during outdoor activities in the fall, including minimizing exposed skin and using insect repellent. A city official advised that anyone who develops symptoms such as fever, chills or headache after visiting a country where malaria is endemic or a domestic high-risk area should visit a nearby public health center or medical facility for testing.

The Seoul Metropolitan Government Institute of Health and Environment also called for preventive measures, noting that mosquito activity is expected to intensify as the heat wave eases. An institute official said residents should remove standing water near their homes, wear long-sleeved shirts and long pants when going outdoors, and use mosquito repellent.


ken@heraldcorp.com
ikson@heraldcorp.com