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Table 2 Risk factors associated with antibodies a against Toxoplasma gondii among participants ≥6 years old; NHANES 1999–2004, 2009-10 b

From: Drinking water source and human Toxoplasma gondii infection in the United States: a cross-sectional analysis of NHANES data

Variable N IgG positivec Unadjusted ORd Adjusted ORd
   n (%) (95% CI) (95% CI)
Survey year     
 1999-2000 5089 602 (13.3) Ref Ref
 2001-2002 5751 527 (9.3) 0.7 (0.5-0.9) e 0.7 (0.5-0.9)
 2003-2004 5120 434 (10.8) 0.8 (0.6-1.0) 0.8 (0.6-1.1)
 2009-2010 7070 1079 (13.2) 1.0 (0.8-1.2) 0.6 (0.5-0.7)
Age     
Continuous (years) 23030 2642 (11.7) 1.03 (1.03-1.03) 1.03 (1.03-1.04)
Age group (years)     
 6-12 4274 155 (3.5) Ref --
 13-17 4693 279 (4.6) 1.4 (1.03-1.8) --
 18-28 4810 488 (9.2) 2.8 (2.3-3.5) --
 29-43 4799 757 (14.0) 4.5 (3.6-5.8) --
 ≥44 4450 963 (17.7) 6.0 (4.5-8.0) --
Gender     
 Female 11791 1240 (10.8) Ref Ref
 Male 11239 1402 (12.6) 1.2 (1.04-1.4) 1.2 (1.1-1.4)
Race/Ethnicity     
 Non-Hispanic White 8546 854 (9.9) Ref Ref
 Non-Hispanic Black 5535 566 (12.6) 1.3 (1.1-1.6) 1.3 (1.04-1.6)
 Mexican American 6441 749 (13.6) 1.4 (1.2-1.7) 0.5 (0.4-0.7)
 Other Hispanic 1490 366 (24.8) 3.0 (2.3-4.0) 1.6 (1.3-2.1)
 Other, incl. multiracial 1018 107 (12.9) 1.3 (1.02-1.8) 0.7 (0.5-1.0)
Household food securityf     
 Full food security 15104 1593 (10.9) Ref Ref
 Marginally secure or insecure 7212 973 (14.5) 1.4 (1.2-1.6) 1.3 (1.1-1.5)
Smoking statusf,g     
 Non-smoker 18438 1977 (11.0) Ref Ref
 Light smoker/moderate second-hand exposure 1387 194 (13.0) 1.2 (1.0-1.5) 1.1 (0.9-1.4)
 Smoker 3045 447 (14.1) 1.3 (1.1-1.6) 1.2 (1.03-1.5)
Country of originf     
 United States 18358 1401 (8.9) Ref Ref
 Mexico 2661 614 (24.1) 3.2 (2.7-3.9) 6.3 (4.7-8.4)
 Elsewhere 2005 627 (29.2) 4.2 (3.4-5.2) 3.7 (3.0-4.6)
Source and home treatmenth of tap waterf     
 Home-treated private/public water company 4129 420 (9.9) Ref Ref
 Home-untreated private/public water company 16089 1855 (12.1) 1.2 (1.1-1.4) 1.2 (1.003-1.4)
 Home-treated well water 1056 143 (12.7) 1.3 (1.05-1.7) 1.4 (1.1-1.8)
 Home-untreated well water 1107 143 (12.3) 1.3 (0.9-1.8) 1.5 (1.02-2.2)
General health conditionf     
 Excellent 6341 477 (8.5) Ref Ref
 Very good 6306 588 (9.8) 1.2 (1.0-1.4) 1.1 (0.9-1.3)
 Good 7090 920 (13.3) 1.7 (1.4-1.9) 1.2 (1.04-1.4)
 Fair 2835 552 (19.2) 2.6 (2.2-2.9) 1.5 (1.3-1.8)
 Poor 447 103 (25.1) 3.6 (2.6-5.0) 1.9 (1.4-2.7)
Took treatment for anemia in past 3 monthsf     
 No 22397 2526 (11.5) Ref Ref
 Yes 625 113 (18.5) 1.7 (1.3-2.3) 1.4 (1.01-2.0)
Blood eosinophils numberf     
 Continuous (1000 cells/uL) 22940 2629 (11.7) 1.4 (1.02-1.9) 1.3 (1.0-1.7)
  1. aFor Continuous NHANES 1999–2004: IgG ≥10 IU = positive; IgG <10 IU = negative. For Continuous NHANES 2009–2010: IgG ≥33 IU/mL = positive; IgG <33 IU/mL = negative. b T. gondii serology performed only among participants ages 6–49 for 1999–2004 data. cAll prevalence estimates were weighted. dWald Chi-square logistic regression used. eBolded font denotes statistically significant data (P < 0.05). fCovariate has some missing data. gBased on serum cotinine level (ng/mL); nonsmoker <10, light smoker/second-hand exposure 10–99, smoker ≥100. hTypes of home water treatment devices included: Brita® or other pitcher water filter, ceramic or charcoal filter, water softener, aerator, reverse osmosis.