Table 1.

Weighted seroprevalence by participant characteristics among nonsmokers, NHANES 1999–2012

Characteristic	H. pylori			T. gondii			Hepatitis B virus
	N	Positive (%)a	P b	N	Positive (%)a	P b	N	Positive (%)a	P b
Total	5994	23.1		18,425	11.0		17,389	4.9
NHANES cycle years
1999–2000	5994	23.1	–	4084	13.5	0.0001	2926	5.0	0.8283
2001–2002	–	–		4669	8.0		2955	4.5
2003–2004	–	–		4089	9.3		2420	5.7
2005–2006	–	–		–	–		2157	5.3
2007–2008	–	–		–	–		2507	4.3
2009–2010	–	–		5583	12.8		2466	5.0
2011–2012	–	–		–			1958	4.9
Age (years)
≤ 13	1721	7.2	<0.0001	5127	3.5	<0.0001	613	0.4	<0.0001
14–40	2307	20.2		9252	10.5		4788	2.9
≥ 41	1966	33.4		4046	16.2		11,988	5.9
Gender
Male	2785	22.7	0.5279	8529	11.5	0.1633	8171	5.5	0.0185
Female	3209	23.5		9896	10.5		9218	4.5
Race
Non-Hispanic White	1912	14.6	<0.0001	6320	9.0	<0.0001	8365	2.6	<0.0001
Non-Hispanic Black	1300	37.2		4313	11.7		3124	13.4
Mexican American	2586	45.2		6967	17.2		5083	4.3
Other	196	31.2		825	12.4		817	27.4
Family income
≥ $20,000	2991	18.3	<0.0001	10,997	9.6	<0.0001	10,661	4.0	<0.0001
< $20,000	2650	31.5		6725	14.3		6027	7.4
Country of birth origin
United States	4675	17.6	<0.0001c	14,417	7.7	<0.0001	12,919	3.2	<0.0001
Other	1314	53.4		4002	27.3		4459	14.0
General health condition
Excellent/very good	3190	17.2	<0.0001	10,634	8.2	<0.0001	7622	3.8	<0.0001
Good	1855	28.0		5452	13.7		5829	5.6
Fair/poor	943	42.0		2330	20.9		3925	7.5
Source of tap water
Municipal	5306	22.9	0.9746	16,294	10.9	0.9501	13,218	5.4	<0.0001
Public/private well	589	23.0		1768	11.0		1962	2.6
Crowded housingd
≤ 1 person/room	4109	20.9	<0.0001	12,739	10.1	<0.0001	12,872	4.8	0.0091
> 1 person/room	1806	34.2		5490	15.7		2401	6.5
Injected drug user
No/unknown	–	–	–	18,377	8.4	0.5850	17,294	4.8	<0.0001
Yes	–	–		48	11.0		95	18.5

^aWeighted percentages

^bRao-Scott chi-square test used

^cUnweighted Wald chi-square used

^dCalculated as total number of individuals living in a household divided by number of rooms in the home (excluding bathroom and kitchen)