Table 1.
General characteristics of scrub typhus cases between January and December 2009 in Korea
| Item | Male | Female | Total | p∗ |
|---|---|---|---|---|
| Age (yr) | ||||
| <50 | 415 (24.8) | 453 (16.3) | 868 (19.5) | <0.001 |
| 50–59 | 342 (20.4) | 600 (21.6) | 942 (21.1) | |
| 60–69 | 431 (25.7) | 741 (26.6) | 1,172 (26.3) | |
| ≥70 | 488 (29.1) | 990 (35.6) | 1,478 (33.1) | |
| Occupation | ||||
| Farmers | 750 (50.4) | 1,232 (47.0) | 1,982 (47.8) | 0.037 |
| Non-farmers | 739 (49.6) | 1,390 (53.0) | 2,129 (52.2) | |
| Region | ||||
| Urban | ||||
| Seoul | 49 (3.1) | 58 (2.2) | 107 (2.5) | |
| Busan | 112 (7.0) | 176 (6.6) | 288 (6.8) | |
| Daegu | 36 (2.3) | 65 (2.4) | 101 (2.4) | |
| Inchon | 32 (2.0) | 47 (1.8) | 79 (1.9) | |
| Gwangju | 41 (2.6) | 52 (2.0) | 93 (2.2) | |
| Daejeon | 73 (4.6) | 95 (3.6) | 168 (3.9) | |
| Ulsan | 68 (4.3) | 124 (4.7) | 192 (4.5) | |
| Sub-total | 411 (25.7) | 617 (23.2) | 1,028 (24.2) | |
| Rural | ||||
| Gangwon | 7 (0.4) | 31 (1.2) | 38 (0.9) | |
| Gyeonggi | 155 (9.7) | 186 (7.0) | 341 (8.0) | |
| Chungbuk | 50 (3.1) | 120 (4.5) | 170 (4.0) | |
| Chungnam | 233 (13.9) | 380 (14.3) | 603 (14.2) | |
| Jeonbuk | 233 (14.6) | 417 (15.7) | 650 (15.3) | |
| Jeonnam | 209 (13.1) | 429 (16.2) | 63 8 (15.0) | |
| Gyeongbuk | 114 (7.1) | 199 (7.5) | 313 (7.4) | |
| Gyeongnam | 192 (12.0) | 268 (10.1) | 460 (10.8) | |
| Jeju | 6 (0.4) | 7 (0.3) | 13 (0.3) | |
| Sub-total | 1,189 (74.3) | 2,037 (76.8) | 3,226 (75.8) | |
| Month | ||||
| January–September | 131 (7.8) | 192 (6.9) | 323 (7.3) | 0.486 |
| October | 907 (54.3) | 1,482 (53.3) | 2,389 (53.7) | |
| November | 600 (35.9) | 1,049 (37.7) | 1,649 (37.0) | |
| December | 33 (2.0) | 58 (2.1) | 91 (2.0) | |
| Infection risk factor | ||||
| Only fieldwork† | 673 (46.3) | 1,135 (46.8) | 1,808 (46.6) | 0.706 |
| Only outdoor activity‡ | 692 (47.7) | 1,161 (47.9) | 1,853 (47.8) | |
| Both fieldwork and outdoor activity | 87 (6.0) | 130 (5.4) | 217 (5.6) | |
| Non-recognized infection risk factor | ||||
| Impossible to estimate | 198 (88.4) | 341 (95.0) | 539 (92.5) | 0.003 |
| Possible to estimate | 26 (11.6) | 18 (5.0) | 44 (7.5) | |
| Major symptoms | ||||
| Fever | 1,450 (86.5) | 2,433 (87.4) | 3,883 (87.0) | — |
| Chill | 1,052 (62.8) | 1,739 (62.4) | 2,791 (62.6) | |
| Eschar | 1,254 (74.8) | 2,167 (77.8) | 3,421 (76.7) | |
Data n (%).
∗
χ2 test.
†
Fieldwork was defined as continuous agricultural, forestry, or stock breeding work, as well as working in vegetable gardens.
‡
Outdoor activity was defined as the activities that non-farmers irregularly participate in, which may be related to agriculture (such as assisting farmer relatives) or leisure (such as climbing, tracking, gathering chestnuts, mowing around graves, etc.).