Table 1 Bivariate analyses of risk factors associated with outbreak cases (May–July 2017) compared to cases reported in the previous year (May–July 2016)
Characteristics | Outbreak cases (n = 422) | Cases from the previous year (n = 50) | OR [95% CI] | p-value |
|---|---|---|---|---|
Species | ||||
Plasmodium vivax | 308 (73) | 27 (54) | 2.32 [1.27, 4.22] | 0.006 |
Plasmodium falciparum | 113 (27) | 23 (46) | Ref | |
Mixed | 1 (0.002) | 0 (0) | –a | < 0.001 |
District of residence, n (%) b | ||||
Kantharalak | 92 (22) | 10 (20) | 1.12 [0.54, 2.32] | 0.77 |
Khun Han | 191 (45) | 32 (64) | 0.47 [0.25, 0.85] | 0.014 |
Phu Sing | 116 (28) | 5 (10) | 3.41 [1.32, 8.81] | 0.011 |
Other | 23 (5) | 3 (6) | 0.90 [0.26, 3.12] | 0.87 |
Nationality, n (%) | ||||
Thai | 412 (98) | 49 (98) | Ref | |
Cambodian | 10 (2) | 1 (2) | 1.19 [0.15, 9.50] | 0.87 |
Gender, n (%) | ||||
Male | 368 (87) | 48 (96) | Ref | |
Female | 54 (13) | 2 (4) | 3.52 [0.83, 14.91] | 0.087 |
Age in years, n (%) b | ||||
0–14 | 18 (4) | 0 (0) | --a | -- |
15–59 | 386 (91) | 48 (96) | 0.45 [0.10, 1.91] | 0.28 |
≥ 60 | 18 (4) | 2 (4) | 1.07 [0.24, 4.75] | 0.93 |
Travel history b | ||||
No travel | 15 (4) | 8 (16) | 0.19 [0.08, 0.48] | < 0.001 |
Within Thailand | 285 (68) | 33 (66) | 1.07 [0.58, 1.99] | 0.83 |
Outside Thailand | 122 (29) | 9 (18) | 1.85 [0.87, 3.93] | 0.11 |
Main occupation b | ||||
Rubber tapper | 263 (62) | 5 (10) | 14.89 [5.79, 38.29] | < 0.001 |
Soldier/police | 62 (15) | 11 (22) | 0.61 [0.30, 1.26] | 0.18 |
Child/student | 25 (6) | 2 (4) | 1.51 [0.35, 6.58] | 0.58 |
Rice farmer | 15 (4) | 23 (46) | 0.04 [0.02, 0.09] | < 0.001 |
Other | 57 (14) | 9 (18) | 0.71 [0.33, 1.54] | 0.39 |