Table 1 Distribution (%) of potential risk factors among malaria cases (index and secondary cases), non-cases (screened in RACD), and by Plasmodium types
Variable | Non-cases no. (%) (n = 1489) | Cases no. (%) (n = 43) | P | Cases by Plasmodium type | |||
|---|---|---|---|---|---|---|---|
Pf no. (%) (n = 8) | Pv no. (%) (n = 15) | Pk no. (%) (n = 20) | P | ||||
Detection method | |||||||
 Passive | n/a | 37 (100) | <0.0001 | 6 (16.2) | 12 (32.4) | 19 (51.4) | 0.253 |
 RACD | 1489 (99.6) | 6 (0.4) | 2 (33.3) | 3 (50.0) | 1 (16.7) | ||
Socio-demographic | |||||||
 Age category (years) | |||||||
  ≤15 | 481 (99.6) | 2 (0.4) | <0.0001 | 0 (0.0) | 0 (0.0) | 2 (100) | 0.033 |
  16–30 | 362 (94.3) | 22 (5.7) | 4 (18.2) | 12 (54.6) | 6 (27.3) | ||
  31–45 | 356 (94.9) | 19 (5.1) | 4 (21.0) | 3 (15.8) | 12 (63.2) | ||
  46 + | 290 (100) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | ||
 Gender | |||||||
  Female | 836 (99.6) | 3 (0.4) | <0.0001 | 0 (0.0) | 0 (0.0) | 3 (100) | 0.281 |
  Male | 653 (94.2) | 40 (5.8) | 8 (20.0) | 15 (37.5) | 17 (42.5) | ||
 Education of household head |  | ||||||
  No school | 40 (95.2) | 2 (4.8) | 0.072 | 0 (0.0) | 0 (0.0) | 2 (100) | 0.006 |
  Primary school | 481 (98.0) | 10 (2.0) | 1 (10.0) | 8 (80.0) | 1 (10.0) | ||
  Secondary school | 670 (96.1) | 27 (3.9) | 7 (25.9) | 7 (25.9) | 13 (48.2) | ||
  Tertiary school | 298 (98.7) | 4 (1.3) | 0 (0.0) | 0 (0.0) | 4 (100) | ||
 Occupation category | |||||||
  Unemployed | 281 (99.7) | 1 (0.3) | <0.0001 | 0 (0.0) | 1 (100) | 0 (0.0) | 0.112 |
  Not forest-related job | 847 (98.6) | 12 (1.4) | 1 (8.3) | 2 (16.7) | 9 (75.0) | ||
  Forest-related job | 361 (92.3) | 30 (7.7) | 7 (23.3) | 12 (40.0) | 11 (36.7) | ||
 Wealth index (quintile) | |||||||
  1st | 295 (96.1) | 12 (3.9) | 0.517 | 3 (25.0) | 2 (16.7) | 7 (58.3) | 0.470 |
  2nd | 306 (97.8) | 7 (2.2) | 1 (14.3) | 3 (42.9) | 3 (42.9) | ||
  3rd | 302 (97.4) | 8 (2.6) | 3 (37.5) | 3 (37.5) | 2 (25.0) | ||
  4th | 444 (97.8) | 10 (2.2) | 1 (10.0) | 3 (30.0) | 6 (60.0) | ||
  5th | 142 (95.9) | 6 (4.1) | 0 (0.0) | 4 (66.7) | 2 (33.3) | ||
 Subdistrict | |||||||
  Lembah Seulawah | 525 (97.2) | 15 (2.8) | 0.978 | 2 (13.3) | 1 (6.7) | 12 (80.0) | <0.0001 |
  Kuta Cot Glie | 374 (97.4) | 10 (2.6) | 6 (60.0) | 1 (10.0) | 3 (30.0) | ||
  Lhoong | 511 (97.0) | 16 (3.0) | 0 (0.0) | 12 (75.0) | 4 (25.0) | ||
  Indrapuri | 79 (97.5) | 2 (2.5) | 0 (0.0) | 1 (50.0) | 1 (50.0) | ||
  Lhoknga | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | ||
Prevention and behaviours | |||||||
 Travel | |||||||
  No | 1340 (98.6) | 19 (1.4) | <0.0001 | 1 (5.3) | 6 (31.6) | 12 (63.2) | 0.071 |
  Yes | 149 (86.1) | 24 (13.9) | 7 (29.2) | 9 (37.5) | 8 (33.3) | ||
 ITN ownership | |||||||
  No ITN | 499 (96.2) | 20 (3.8) | 0.119 | 4 (20.0) | 6 (30.0) | 10 (50.0) | 0.911 |
  <1 ITN/2 people | 712 (98.1) | 14 (1.9) | 2 (14.3) | 5 (35.7) | 7 (50.0) | ||
  ≥1 ITN/2 people | 278 (96.9) | 9 (3.1) | 2 (22.2) | 4 (44.4) | 3 (33.3) | ||
 Slept under a bed net previous night | |||||||
  No | 658 (96.0) | 27 (4.0) | 0.016 | 7 (25.9) | 9 (33.3) | 11 (40.7) | 0.264 |
  Yes | 831 (98.1) | 16 (1.9) | 1 (6.3) | 6 (37.5) | 9 (56.3) | ||
 House sprayed in previous 1 year | |||||||
  No | 1381 (97.2) | 40 (2.8) | 0.945 | 8 (20.0) | 13 (32.5) | 19 (47.5) | 0.575 |
  Yes | 108 (97.3) | 3 (2.7) | 0 (0.0) | 2 (66.7) | 1 (33.3) | ||
 Slept outside house previous night | |||||||
  No | 1459 (97.1) | 43 (2.9) | 0.347 | 8 (18.6) | 15 (34.9) | 20 (46.5) | n/a |
  Yes | 30 (100) | 0 (0.0) |  | 0 (0.0) | 0 (0.0) | 0 (0.0) |  |
Forest exposure and environment | |||||||
 Workplace near or in forest | |||||||
  No | 1027 (99.2) | 8 (0.8) | <0.0001 | 0 (0.0) | 3 (37.5) | 5 (62.5) | 0.401 |
  Yes, overnights not required | 273 (98.6) | 4 (1.4) | 0 (0.0) | 1 (25.0) | 3 (75.0) | ||
  Yes, overnights required | 189 (85.9) | 31 (14.1) | 8 (25.8) | 11 (35.5) | 12 (38.7) | ||
   Distance workplace to forest (km)a | |||||||
    In forest | 209 (87.8) | 29 (12.2) | <0.0001 | 7 (24.1) | 12 (41.4) | 10 (34.5) | 0.373 |
    <1 | 191 (98.0) | 4 (2.0) | 1 (25.0) | 0 (0.0) | 3 (75.0) | ||
    1–5 | 59 (98.3) | 1 (1.7) | 0 (0.0) | 0 (0.0) | 1 (100) | ||
    >5–10 | 3 (75.0) | 1 (25.0) | 0 (0.0) | 0 (0.0) | 1 (100) | ||
 Visited forest in the last month for any reason | |||||||
  No | 1241 (99.0) | 12 (1.0) | <0.0001 | 1 (8.3) | 4 (33.3) | 7 (58.3) | 0.552 |
  Yes | 248 (88.9) | 31 (11.1) | 7 (22.6) | 11 (35.5) | 13 (41.9) | ||
  Main reasonb | |||||||
   Residence | 108 (94.7) | 6 (5.3) | 0.029 | 0 (0.0) | 1 (16.7) | 5 (83.3) | 0.032 |
   Work | 111 (84.1) | 21 (15.9) | 6 (28.6) | 10 (47.6) | 5 (23.8) | ||
   Other reasonc | 29 (87.9) | 4 (12.1) | 1 (25.0) | 0 (0.0) | 3 (75.0) | ||
  Median visit (days), rangeb | 30 (1–30) | 14 (1–30) | 0.002 | 14 (4–30) | 10 (1–30) | 25 (3–30) | 0.603 |
 Malaria transmission season | |||||||
  Low | 717 (97.6) | 18 (2.4) | 0.415 | 3 (16.7) | 6 (33.3) | 9 (50.0) | 0.921 |
  High | 772 (96.9) | 25 (3.1) | 5 (20.0) | 9 (36.0) | 11 (44.0) | ||
 Reported living near water body | |||||||
  No | 633 (98.0) | 13 (2.0) | 0.108 | 3 (23.1) | 2 (15.4) | 8 (61.5) | 0.204 |
  Yes | 856 (96.6) | 30 (3.4) | 5 (16.7) | 13 (43.3) | 12 (40.0) | ||
  Distance living to water bodyd (m) | |||||||
   <100 | 435 (96.0) | 18 (4.0) | 0.609 | 2 (11.1) | 8 (44.4) | 8 (44.4) | 0.563 |
   100–499 | 168 (97.1) | 5 (2.9) | 2 (40.0) | 1 (20.0) | 2 (40.0) | ||
   ≥500 | 253 (97.3) | 7 (2.7) | 1 (14.3) | 4 (57.1) | 2 (28.6) | ||
 Reported living near or in forest | |||||||
  No | 712 (97.4) | 19 (2.6) | 0.638 | 4 (21.1) | 8 (42.1) | 7 (36.8) | 0.566 |
  Yes | 777 (97.0) | 24 (3.0) | 4 (16.7) | 7 (29.2) | 13 (54.2) | ||
  Distance living to foreste (km) | |||||||
   In forest | 147 (96.1) | 6 (3.9) | 0.651 | 0 (0.0) | 1 (16.7) | 5 (83.3) | 0.040 |
   <1 | 440 (96.9) | 14 (3.1) | 3 (21.4) | 3 (21.4) | 8 (57.1) | ||
   1-5 | 170 (98.3) | 3 (1.7) | 0 (0.0) | 3 (100) | 0 (0.0) | ||
   >5 and <10 | 20 (95.2) | 1 (4.8) | 1 (100) | 0 (0.0) | 0 (0.0) | ||
 Housing quality, composite variable | |||||||
  Good | 831 (97.7) | 20 (2.4) | 0.162 | 3 (15.0) | 7 (35.0) | 10 (50.0) | 0.181 |
  Moderate | 335 (95.7) | 15 (4.3) | 1 (6.7) | 7 (46.7) | 7 (46.7) | ||
  Poor | 323 (97.6) | 8 (2.4) | 4 (50.0) | 1 (12.5) | 3 (37.5) | ||