Table 3

Univariable analysis for identification of environmental factors associated with a positive diagnosis of Aspergillus species in air samples during the second 12-month period: May 16, 2013 to May 8, 2014

VariableCategoryNegativePositiveCrude OR95% CIp value
N = 415 (100%)N = 110 (100%)
Park geographyWest63 (15)12 (11)1ReferenceNA
Central97 (23)28 (25)1.520.72, 3.200.27
East255 (62)70 (64)1.440.74, 2.820.28
InfrastructureIndoor with HEPA and other infection control measures116 (28)9 (8)1ReferenceNA
Indoor without HEPA and other infection control measures125 (30)50 (45)5.162.43, 10.94< 0.01
Outdoor174 (42)51 (47)3.781.79, 7.96< 0.01
OutdoorNo241 (58)59 (54)1ReferenceNA
Yes174 (42)51 (46)1.20.78, 1.830.4
Outside accessNo125 (30)25 (23)1ReferenceNA
Yes290 (70)85 (77)1.470.90, 2.150.12
Sunlight exposureNo163 (39)37 (34)1ReferenceNA
Yes252 (61)73 (66)1.280.82, 1.980.27
Pool presentNo133 (32)42 (38)1ReferenceNA
Yes282 (68)68 (62)0.760.49, 1.180.22
Substrate humidNo245 (59)65 (59)1ReferenceNA
Yes170 (61)45 (41)10.65, 1.530.99
Fans onNo223 (54)84 (76)1ReferenceNA
Yes192 (46)26 (34)0.360.22, 0.58< 0.01
Substrate typeConcrete352 (85)98 (89)1ReferenceNA
Dirt38 (9)12 (11)1.130.57, 2.250.71
Snow25 (6)0 (0)NDNDND
Organic matter in areaNo256 (62)60 (55)1ReferenceNA
Yes159 (38)50 (45)1.340.88, 2.050.17
Wood substrate in areaNo237 (57)63 (57)1ReferenceNA
Yes178 (43)47 (43)0.990.65, 1.520.97
Construction in areaNo410 (99)109 (99)1ReferenceNA
Yes5 (1)1 (1)0.750.09, 6.510.79
Construction in parkNo364 (88)98 (89)1ReferenceNA
Yes51 (12)12 (11)0.870.45, 1.700.69
Weather variablesNo242 (58)73 (66)1ReferenceNA
Warm monthsYes173 (42)37 (34)0.710.46, 1.100.12
Ave temperature (C)11.7 to 16.740 (10)2 (1)0.130.03, 0.54< 0.01
17.2 to 18.9212 (51)82 (75)1ReferenceNA
19.4 to 25.6163 (39)26 (24)0.410.25, 0.67< 0.01
Ave humidity (%)29 to 64124 (30)44 (40)1.991.21, 3.27< 0.01
65 to 71196 (47)35 (32)1ReferenceNA
72 to 8195 (23)31 (28)1.831.06, 3.140.02
Wind directionOn shore372 (90)90 (82)1ReferenceNA
Along shore43 (10)20 (18)1.921.08, 3.430.02
Wind speed (mph)2 to 5138 (33)30 (17)1ReferenceNA
6 to 12277 (67)80 (73)1.330.83, 2.120.23
Precipitation (inches)0318 (77)81 (75)1ReferenceNA
0.01 to 0.0377 (23)28 (25)1.430.87, 2.340.15
Animals present in areaNo206 (50)49 (45)1ReferenceNA
Yes209 (50)61 (55)1.230.80, 1.870.34
Aspergillosis cases in areaNo396 (95)106 (96)1ReferenceNA
Yes19 (5)4 (4)0.790.26, 2.360.66
Breeding seasonNo347 (84)95 (86)1ReferenceNA
Yes68 (16)15 (14)0.810.44, 1.470.48
  • HEPA, high-efficiency particulate air filtration system; NA, not applicable; ND, not determined.