Background
Methods
Definitions
A confirmed case
A suspected case
An asymptomatic infection
Study protocol
Data management and analysis
Variable | Assignment |
---|---|
Sex | Men = 1, Women = 2 |
Age | 66~86 years old = 1, 56~65 years old =2, 46~55 years old =3, 36~45 years old =4, 26~35 years old =5, 14~25 years old =6, 1~13 years old = 7 |
Education | Primary = 1, Junior = 2, Senior =3, Undergraduate and above =4, Unknown =5, Illiteracy =6 |
Occupation | Farmer and herdsmen =1, Unknown = 2, Nonfarmer and nonherdsmen =3 |
Contact with abortion | Yes = 1, No = 2 |
Contact with fur | Yes = 1, No = 2 |
Contact with feces | Yes = 1, No = 2 |
Contact with dust | Yes = 1, No = 2 |
Family member of infected | Yes = 1, No = 2 |
Results
Baseline characteristics
Confirmed case n (%) | Suspected case n (%) | People without brucellosis n (%) | C vs S vs Pe | C vs S | C vs Pe | S vs Pe | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
X2 | P | X2 | P | X2 | P | X2 | P | |||||||||||
Sex | 89 | .141 | < 0.001 | 3 | .877 | 0.049 | 82 | .664 | < 0.001 | 18 | .482 | < 0.001 | ||||||
Men | 759 | (76.59) | 273 | (71.47) | 1205 | (59.80) | ||||||||||||
Women | 232 | (23.41) | 109 | (28.53) | 810 | (40.20) | ||||||||||||
Age | 64 | .861 | < 0.001 | 10 | .32 | 0.112 | 36 | .423 | < 0.001 | 34 | .573 | < 0.001 | ||||||
≤ 13 | 21 | (2.12) | 6 | (1.57) | 132 | (6.55) | ||||||||||||
14~25 | 99 | (9.99) | 24 | (6.28) | 234 | (11.61) | ||||||||||||
26~35 | 162 | (16.35) | 69 | (18.06) | 364 | (18.06) | ||||||||||||
36~45 | 281 | (28.36) | 128 | (33.51) | 524 | (26.00) | ||||||||||||
46~55 | 271 | (27.35) | 92 | (24.08) | 470 | (23.33) | ||||||||||||
56~65 | 129 | (13.02) | 56 | (14.66) | 225 | (11.17) | ||||||||||||
≥ 66 | 28 | (2.83) | 7 | (1.83) | 66 | (3.28) | ||||||||||||
Education | 21 | .509 | 0.018 | 5 | .452 | 0.340 | 18 | .901 | 0.002 | 3 | .947 | 0.557 | ||||||
Illiteracy | 52 | (5.25) | 15 | (3.93) | 116 | (5.76) | ||||||||||||
Primary edu | 611 | (61.65) | 234 | (61.26) | 1202 | (59.65) | ||||||||||||
Junior edu | 296 | (29.87) | 112 | (29.32) | 559 | (27.74) | ||||||||||||
Senior edu | 27 | (2.72) | 17 | (4.45) | 99 | (4.91) | ||||||||||||
Undergraduate & above | 3 | (0.30) | 3 | (0.79) | 29 | (1.44) | ||||||||||||
Unknown | 2 | (0.20) | 1 | (0.26) | 10 | (0.50) | ||||||||||||
Occupation | 155 | .747 | < 0.001 | 12 | .754 | 0.415 | 123 | .857 | < 0.001 | 54 | .654 | < 0.001 | ||||||
Farmers and herdsmen | 838 | (84.56) | 331 | (86.65) | 1527 | (75.78) | ||||||||||||
Livestock merchant | 6 | (0.61) | 3 | (0.79) | 21 | (1.04) | ||||||||||||
Livestock slaughterer | 9 | (0.91) | 1 | (0.26) | 14 | (0.69) | ||||||||||||
Dairy processor | 6 | (0.61) | 2 | (0.52) | 7 | (0.35) | ||||||||||||
Fur-making worker | 2 | (0.20) | 0 | (0.00) | 2 | (0.10) | ||||||||||||
Other worker | 10 | (1.01) | 4 | (1.05) | 60 | (2.98) | ||||||||||||
Veterinarian | 3 | (0.30) | 2 | (0.52) | 7 | (0.35) | ||||||||||||
Doctor or nurse | 0 | (0.00) | 1 | (0.26) | 6 | (0.30) | ||||||||||||
Student | 13 | (1.31) | 7 | (1.83) | 75 | (3.72) | ||||||||||||
Children | 12 | (1.21) | 2 | (0.52) | 79 | (3.92) | ||||||||||||
Unemployed | 3 | (0.30) | 0 | (0.00) | 35 | (1.74) | ||||||||||||
Officer | 0 | (0.00) | 2 | (0.52) | 30 | (1.49) | ||||||||||||
Freelancer | 25 | (2.52) | 7 | (1.83) | 99 | (4.91) | ||||||||||||
Unknown | 64 | (6.46) | 20 | (5.24) | 53 | (2.63) |
Confirmed case n (%) | Suspected case n (%) | People without brucellosis n (%) | C vs S vs Pe | C vs S | C vs Pe | S vs Pe | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
X2 | P | X2 | P | X2 | P | X2 | P | |||||||
Contact with animals | ||||||||||||||
Cattle | 12.891 | 0.002 | 2.486 | 0.115 | 5.338 | 0.021 | 9.601 | 0.002 | ||||||
yes | 85 | (8.58) | 23 | (6.02) | 228 | (11.32) | ||||||||
no | 906 | (91.42) | 359 | (93.98) | 1787 | (88.68) | ||||||||
Sheep | 65.415 | < 0.001 | 1.217 | 0.270 | 58.904 | < 0.001 | 17.383 | < 0.001 | ||||||
yes | 654 | (65.99) | 240 | (62.83) | 1032 | (51.22) | ||||||||
no | 337 | (34.01) | 142 | (37.17) | 983 | (48.78) | ||||||||
Swine | 9.649 | 0.008 | 9.742 | 0.002 | 2.532 | 0.112 | 4.785 | 0.029 | ||||||
yes | 64 | (6.46) | 44 | (11.52) | 163 | (8.09) | ||||||||
no | 927 | (93.54) | 338 | (88.48) | 1852 | (91.91) | ||||||||
Deer | 0.582 | 0.843 | – | – | – | – | – | – | ||||||
yes | 5 | (0.50) | 1 | (0.26) | 7 | (0.35) | ||||||||
no | 986 | (99.50) | 381 | (99.74) | 2008 | (99.65) | ||||||||
Canine | 2.376 | 0.305 | – | – | – | – | – | – | ||||||
yes | 162 | (16.35) | 59 | (15.45) | 287 | (14.24) | ||||||||
no | 829 | (83.65) | 323 | (84.55) | 1728 | (85.76) | ||||||||
Contact with substances | ||||||||||||||
Abortion products | 213.426 | < 0.001 | 1.945 | 0.163 | 194.577 | < 0.001 | 72.951 | < 0.001 | ||||||
yes | 446 | (45.01) | 156 | (40.84) | 414 | (20.55) | ||||||||
no | 545 | (54.99) | 226 | (59.16) | 1601 | (79.45) | ||||||||
Dairy and meat | 4.182 | 0.124 | – | – | – | – | – | – | ||||||
yes | 34 | (3.43) | 15 | (3.93) | 101 | (5.01) | ||||||||
no | 957 | (96.57) | 367 | (96.07) | 1914 | ((94.99) | ||||||||
Fur | 43.090 | < 0.001 | 0.011 | 0.915 | 35.375 | < 0.001 | 16.015 | < 0.001 | ||||||
yes | 649 | (65.49) | 249 | (65.18) | 1090 | (54.09) | ||||||||
no | 342 | (34.51) | 133 | (34.82) | 925 | (45.91) | ||||||||
Feces | 84.272 | < 0.001 | 0.370 | 0.543 | 66.699 | < 0.001 | 45.770 | < 0.001 | ||||||
yes | 231 | (23.31) | 95 | (24.87) | 238 | (11.81) | ||||||||
no | 760 | (76.69) | 287 | (75.13) | 1777 | (88.19) | ||||||||
Dust | 15.424 | < 0.001 | 2.490 | 0.115 | 15.426 | < 0.001 | 0.977 | 0.323 | ||||||
yes | 305 | (30.78) | 101 | (26.44) | 485 | (24.07) | ||||||||
no | 686 | (69.22) | 281 | (73.56) | 1530 | (75.93) |
Confirmed case n (%) | Suspected case n (%) | People without brucellosis n (%) | C vs S vs Pe | C vs S | C vs Pe | S vs Pe | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
X2 | P | X2 | P | X2 | P | X2 | P | ||||||||
Fever | 330 | .505 | < 0.001 | 8.466 | 0.004 | 300.494 | < 0.001 | 86.074 | < 0.001 | ||||||
yes | 732 | (73.86) | 252 | (65.97) | 811 | (40.25) | |||||||||
no | 259 | (26.14) | 130 | (34.03) | 1204 | (59.75) | |||||||||
Chills | 10 | .363 | 0.006 | 0.081 | 0.776 | 9.314 | 0.002 | 3.409 | 0.065 | ||||||
yes | 117 | (11.81) | 43 | (11.26) | 168 | (8.34) | |||||||||
no | 874 | (88.19) | 339 | (88.74) | 1847 | (91.66) | |||||||||
Acratia | 7 | .303 | 0.026 | 0.812 | 0.367 | 7.235 | 0.007 | 0.794 | 0.373 | ||||||
yes | 392 | (39.56) | 141 | (36.91) | 696 | (34.54) | |||||||||
no | 599 | (60.44) | 241 | (63.09) | 1319 | (65.46) | |||||||||
Hyperhidrosis | 119 | .031 | < 0.001 | 3.369 | 0.066 | 113.247 | < 0.001 | 30.548 | < 0.001 | ||||||
yes | 369 | (37.24) | 122 | (31.94) | 389 | (19.31) | |||||||||
no | 622 | (62.76) | 260 | (68.06) | 1626 | (80.69) | |||||||||
Dizziness | 0 | .490 | 0.783 | – | – | – | – | – | – | ||||||
yes | 21 | (2.12) | 8 | (2.09) | 50 | (2.48) | |||||||||
no | 970 | (97.88) | 374 | (97.91) | 1965 | (97.52) | |||||||||
Headache | 57 | .392 | < 0.001 | 0.222 | 0.638 | 51.125 | < 0.001 | 21.371 | < 0.001 | ||||||
yes | 235 | (23.71) | 86 | (22.51) | 269 | (13.35) | |||||||||
no | 756 | (76.29) | 296 | (77.49) | 1746 | (86.65) | |||||||||
Cough | 0 | .153 | 0.926 | – | – | – | – | – | – | ||||||
yes | 20 | (2.02) | 8 | (2.09) | 45 | (2.23) | |||||||||
no | 971 | (97.98) | 374 | (97.91) | 1970 | (97.77) | |||||||||
Joint and muscle pain | 63 | .716 | < 0.001 | 0.158 | 0.691 | 55.357 | < 0.001 | 23.535 | < 0.001 | ||||||
yes | 359 | (36.23) | 134 | (35.08) | 470 | (23.33) | |||||||||
no | 632 | (63.77) | 248 | (64.92) | 1545 | (76.67) | |||||||||
Muscular soreness | 24 | .294 | < 0.001 | 0.387 | 0.534 | 17.532 | < 0.001 | 14.175 | < 0.001 | ||||||
yes | 150 | (15.14) | 63 | (16.49) | 200 | (9.93) | |||||||||
no | 841 | (84.86) | 319 | (83.51) | 1815 | (90.07) | |||||||||
Omalgia | 2 | .676 | 0.262 | – | – | – | – | – | – | ||||||
yes | 43 | (4.34) | 16 | (4.19) | 65 | (3.23) | |||||||||
no | 948 | (95.66) | 366 | (95.81) | 1950 | (96.77) | |||||||||
Wrist pain | 0 | .582 | 0.837 | – | – | – | – | – | – | ||||||
yes | 5 | (0.50) | 1 | (0.26) | 7 | (0.35) | |||||||||
no | 986 | (99.50) | 381 | (99.74) | 2008 | (99.65) | |||||||||
Lumbago | 41 | .410 | < 0.001 | 2.899 | 0.089 | 41.003 | < 0.001 | 6.558 | 0.010 | ||||||
yes | 198 | (19.98) | 61 | (15.97) | 228 | (11.32) | |||||||||
no | 793 | (80.02) | 321 | (84.03) | 1787 | (88.68) | |||||||||
Coxalgia | 19 | .362 | < 0.001 | 0.092 | 0.762 | 15.361 | < 0.001 | 10.847 | 0.001 | ||||||
yes | 63 | (6.36) | 26 | (6.81) | 66 | (3.28) | |||||||||
no | 928 | (93.64) | 356 | (93.19) | 1949 | (96.72) | |||||||||
Sacroiliac pain | 0 | .925 | 0.738 | – | – | – | – | – | – | ||||||
yes | 3 | (0.30) | 2 | (0.52) | 6 | (0.30) | |||||||||
no | 988 | (99.70) | 380 | (99.48) | 2009 | (99.70) | |||||||||
Gonalgia | 10 | .661 | 0.005 | 0.748 | 0.387 | 6.065 | 0.014 | 7.560 | 0.006 | ||||||
yes | 140 | (14.13) | 61 | (15.97) | 222 | (11.02) | |||||||||
no | 851 | (85.87) | 321 | (84.03) | 1793 | (88.98) | |||||||||
Dolor vagus | 27 | .616 | < 0.001 | 0.143 | 0.705 | 21.253 | < 0.001 | 13.960 | < 0.001 | ||||||
yes | 224 | (22.60) | 90 | (23.56) | 317 | (15.73) | |||||||||
no | 767 | (77.40) | 292 | (76.44) | 1698 | (84.27) | |||||||||
Lymphatic swelling | 4 | .580 | 0.079 | – | – | – | – | – | – | ||||||
yes | 2 | (0.20) | 3 | (0.79) | 3 | (0.15) | |||||||||
no | 989 | (99.80) | 379 | (99.21) | 2012 | (99.85) | |||||||||
Enlargement of testis | 21 | .422 | < 0.001 | 0.232 | 0.630 | 20.433 | < 0.001 | 7.883 | 0.005 | ||||||
yes | 42 | (4.24) | 14 | (3.66) | 31 | (1.54) | |||||||||
no | 949 | (95.76) | 368 | (96.34) | 1984 | (98.46) |
Analysis of risk factors of brucellosis
Group | Influencing factor | B | Std. Error | Wald | Sig. | Exp(B) | 95% CI for Exp(B) | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Lower | Upper | ||||||||||||||
Confirmed case | Sex | 0 | .810 | 0 | .096 | 71 | .773 | 0 | .000 | 2 | .249 | 1 | .864 | 2 | .712 |
Age | |||||||||||||||
14~25-years-old | 0 | .652 | 0 | .327 | 3 | .966 | 0 | .046 | 1 | .920 | 1 | .010 | 3 | .647 | |
26~35-years-old | 0 | .674 | 0 | .323 | 4 | .351 | 0 | .037 | 1 | .963 | 1 | .042 | 3 | .700 | |
36~45-years-old | 0 | .790 | 0 | .316 | 6 | .269 | 0 | .012 | 2 | .204 | 1 | .187 | 4 | .091 | |
46~55-years-old | 0 | .889 | 0 | .315 | 7 | .966 | 0 | .005 | 2 | .432 | 1 | .312 | 4 | .507 | |
56~65-years-old | 0 | .917 | 0 | .325 | 7 | .947 | 0 | .005 | 2 | .501 | 1 | .322 | 4 | .730 | |
66~86-years-old | 0 | .782 | 0 | .381 | 4 | .224 | 0 | .040 | 2 | .186 | 1 | .037 | 4 | .608 | |
Farmers and herdsmen | 0 | .360 | 0 | .158 | 5 | .218 | 0 | .022 | 1 | .434 | 1 | .052 | 1 | .953 | |
Unspecified occupation | 1 | .624 | 0 | .253 | 41 | .333 | 0 | .000 | 5 | .071 | 3 | .091 | 8 | .319 | |
Abortion products | 0 | .922 | 0 | .106 | 75 | .005 | 0 | .000 | 2 | .513 | 2 | .040 | 3 | .096 | |
Suspected case | Sex | 0 | .502 | 0 | .129 | 15 | .240 | 0 | .000 | 1 | .652 | 1 | .284 | 2 | .126 |
Farmers and herdsmen | 0 | .639 | 0 | .235 | 7 | .388 | 0 | .007 | 1 | .895 | 1 | .195 | 3 | .004 | |
Unspecified occupation | 1 | .536 | 0 | .350 | 19 | .288 | 0 | .000 | 4 | .646 | 2 | .341 | 9 | .220 | |
Abortion products | 0 | .714 | 0 | .144 | 24 | .629 | 0 | .000 | 2 | .043 | 1 | .541 | 2 | .708 | |
Feces | 0 | .409 | 0 | .189 | 4 | .670 | 0 | .031 | 1 | .506 | 1 | .039 | 2 | .183 |