Herpes simplex virus type 1 and type 2 in the Netherlands: seroprevalence, risk factors and changes during a 12-year period

Table 1 Characteristics of the study population (children and adults^a) of Pienter-1 (1995–6) and Pienter-2 (2006–7)

	Children^a				Adults^a
	Pienter-1		Pienter-2		Pienter-1		Pienter-2
	N	%	N	%	N	%	N	%
Total	1403		1484		2253		2023
Gender
Men	755	53.81	754	50.81	1006	44.65	815	40.29
Women	648	46.19	730	49.19	1247	55.35	1208	59.71
Age (median)	5		5		32		30
Ethnicity^b
Native Dutch	1201	85.60	897	60.44	2019	89.61	1689	83.49
Western, other	74	5.27	57	3.84	131	5.81	152	7.51
Moroccan/Turkish	57	4.06	202	13.61	47	2.09	50	2.47
Surinamese/Aruban/Antillean	24	1.71	164	11.05	27	1.20	50	2.47
Non-Western, other	47	3.35	164	11.05	29	1.29	82	4.05
Generation of migrant^b
Native Dutch	1201	85.60	897	60.44	2019	89.61	1689	83.49
1st generation	41	2.92	286	19.27	123	5.46	174	8.60
2nd generation	161	11.48	301	20.28	111	4.93	160	7.91
Degree of urbanization
Very high	160	11.40	416	28.03	233	10.34	379	18.73
Less high	1243	88.60	1068	71.97	2020	89.66	1644	81.27
Education level^c
Moderate or low	955	68.07	1014	68.33	1794	79.63	1396	69.01
High	421	30.01	431	29.04	436	19.35	601	29.71
Unknown	27	1.92	39	2.63	23	1.02	26	1.29
Household
1-2 persons	19	1.35	46	3.10	724	32.13	643	31.78
3-4 persons	852	60.73	888	59.84	1086	48.20	1000	49.43
> = 5 persons	520	37.06	515	34.70	408	18.11	356	17.60
Unknown	12	0.86	35	2.36	35	1.55	24	1.19
Child in household attending day care
No	1193	85.03	1154	77.76	1972	87.53	1694	83.74
Yes	184	13.11	278	18.73	237	10.52	295	14.58
Unknown	26	1.85	52	3.50	44	1.95	34	1.68
Child attending day care
No	1091	77.76	1058	71.29	-	-	-	-
Yes	281	20.03	382	25.74	-	-	-	-
Unknown	31	2.21	44	2.96	-	-	-	-
Ever had sexual intercourse
No	-	-	-	-	206	9.14	266	13.15
Yes	-	-	-	-	1932	85.75	1668	82.45
Unknown	-	-	-	-	115	5.10	89	4.40

Numbers and percentages were unweighted
^aChildren were aged 6 months to 11 years and adults were aged 17 to 44 years in Pienter-1 and 15 to 44 years in Pienter-2
^bIn Pienter-2, migrant populations (people with at least one parent born abroad) were oversampled
^cFor children, the education level of the parents was used

ISSN: 1471-2334