If you have a black scab where something bit you and a fever right now, stop reading and go to a clinic or public health centre. The Korea Disease Control and Prevention Agency (KDCA) urges anyone who finds an eschar, or develops fever or a rash, within 10 days of outdoor activity to suspect scrub typhus and seek care promptly.
After Chuseok comes grave tidying, harvest and autumn-foliage hiking in Korea. This is when scrub typhus (tsutsugamushi disease) quietly rises. The KDCA announced that it will monitor the chigger mites that carry it at 18 sites nationwide for 16 weeks, from 26 August to 16 December 2026. We carry over the figures and precautions in that release as written and set out what should send you to a doctor.
1. Cases cluster in October and November. Korea records roughly 3,000 to 6,000 cases a year, concentrated in October and November when chigger larvae are most active.
2. Fever within 10 days and a black scab are the signals. Fever, headache, chills, rash and swollen lymph nodes usually appear within 10 days of infection, and an eschar (black scab) at the bite is the hallmark.
3. Larvae are 0.3 mm or smaller. You will not see them, so the advice comes down to two things: avoid bites, and check for a scab in the shower when you get home.
What the disease is
Scrub typhus is caught from the bite of chigger larvae carrying Orientia tsutsugamushi. Chiggers feed on people and animals only as larvae. Larvae hatched from eggs laid in summer appear from early autumn, and their density rises as autumn temperatures change — which is why the season overlaps with farm work, harvest and hiking.
Eight vector chigger species have been reported in Korea, and the dominant species varies by region. In the 2025 surveillance, Leptotrombidium scutellare dominated in the south (such as South Gyeongsang and South Jeolla) and parts of Gyeonggi, and L. pallidum in northern Gangwon and South Chungcheong.
Symptoms — what should send you to a doctor
| What | When | How to check |
|---|---|---|
| Fever, headache, chills | Usually within 10 days of outdoor activity | Even if it starts like a cold, think back to recent time in grass |
| Rash, swollen lymph nodes | As above | Red spots on the trunk; lumps in armpits or groin |
| Eschar (black scab) | At the bite | In the shower, check skin folds such as armpits, waistline and the backs of knees |
The symptom list, “within 10 days” and “the eschar is a key feature” come from the KDCA release; the body areas to check are our additions. When you see a doctor, say first when and where you were outdoors — the KDCA stresses that early detection and proper treatment matter.
Prevention — the KDCA’s three rules
- Do not linger in grass. Stay out of grass above ankle height, and use a mat when you sit or lie down.
- Long clothes and repellent. Wear long sleeves and trousers, long socks, gloves and a hat, and apply tick repellent to shoes, socks and trousers at suitable intervals.
- Wash and check when you get back. Bathe or shower, looking for attached mites and bite marks such as black scabs. Shake out and wash your clothes as soon as you get home.
The release notes that chigger larvae are 0.3 mm or smaller and hard to see with the naked eye. That is why the test should be “was I in the grass?” rather than “did I see a mite?”
Checklist — before and after grave visits and hikes
- ☐ Long sleeves and trousers, long socks, gloves, a hat
- ☐ Tick repellent on shoes, socks and trousers
- ☐ A mat — do not sit directly on grass
- ☐ Shake out and wash clothes on arrival; look for black scabs in the shower
- ☐ For the next 10 days, if fever or rash appears, see a doctor and mention the outdoor activity
Questions that remain
Is there a vaccine?
The release’s prevention measures are avoiding bites and early treatment; it gives no vaccine guidance. Japanese encephalitis, spread by mosquitoes in the same season, is different because an effective vaccine exists.
How many chiggers are there in my area?
The KDCA says weekly surveillance results are published in the “weekly vector surveillance newsletter” on its infectious disease portal. We did not reproduce weekly figures, so check the latest issue.
I am also worried about accidents during grave tidying.
Emergency-call and accident figures around the Chuseok holiday are in Chuseok safety accidents.
Sources
- KDCA press release — “Scrub typhus season approaches: nationwide chigger surveillance begins” (26 August 2026; checked 29 September 2026). Source for 16 weeks and 18 sites, roughly 3,000 to 6,000 cases a year, the October–November peak, symptoms within 10 days and the eschar, eight vector species and their 2025 distribution, larvae of 0.3 mm or less, and the prevention rules.
- Our own arrangement. The “how to check” column and the checklist break the release’s advice into actions.
Where to check further
- Weekly chigger surveillance — the KDCA infectious disease portal’s weekly vector surveillance newsletter.
- If you have symptoms — a nearby clinic or public health centre.
Written on 29 September 2026. Figures and advice are from the KDCA release as written; the tables are ours. This article is not a substitute for medical care.
