Staphylococcus aureus Nasal Colonization in Spanish Children. The COSACO Nationwide Surveillance Study

Figures & data

Table 1 Epidemiological and Clinical Characteristics of the Study Cohort (n=1876)

		n (%)
Age group (years)	0–4	651 (34.7)
	5–9	647 (34.5)
	10–14	578 (30.8)
Mean age in years (SD)*		7.01 (4.38)
Female gender		946 (50.4)
Child’s origin	Foreign	77 (4.1)
	Spanish	1799 (95.9)
Mother’s origin	Foreign	387 (20.6)
	Spanish	1489 (79.4)
Father’s origin	Foreign	357 (19)
	Spanish	1519 (81)
Number of siblings	0	517 (27.5)
	1	1016 (54.2)
	2	252 (13.5)
	3	59 (3.2)
	≥4	32 (1.7)
Mean number of individuals per household (SD)		4.01 (0.99)
Habitat type	Rural	296 (15.8)
	Urban	1188 (64.3)
	Mixed	392 (20.9)
Livestock exposure		192 (10.2)
Pets at home		867 (46.2)
School or daycare attendance		1539 (82)
Antibiotic treatment in the previous month		105 (5.6)
Previous skin infection	Yes	361 (19.2)
	No	1418 (75.6)
	Unknown	97 (5.2)
Other household members with previous skin infections	Yes	94 (5)
	No	1720 (91.6)
	Unknown	62 (3.3)
Hospital admission in the last year		97 (5.2)
Underlying chronic disease	Atopic dermatitis (with no other atopic manifestations)	316 (16.8%)
	Asthma and/or allergies	208 (11.1%)
	Others	109 (5.8%)

Abbreviation: SD, standard deviation.

Table 2 Variables Analyzed as Possible Risk Factors for S. aureus Colonization

Total Population (n=1876)		S. aureus Colonized (n=619) n (%) (95% CI) or Mean (SD)	Magnitude (CI 95%)
Age group (years)	0–4 (n=651)	122 (18.7) (15.7–21.7)	OR 5–14 years: 2.96 (2.36–3.72)*
	5–9 (n=647)	263 (40.7) (36.9–44.4)
	10–14 (n=578)	234 (40.5) (36.5–44.5)
Mean age (years)	Colonized	8.19 (3.96)	MD: 1.75 (1.35–2.15)*
	Not colonized	6.44 (4.50)
Gender	Male (n=930)	339 (36.5) (33.4–39.5)	OR male: 1.36 (1.12–1.66)*
	Female (n=946)	280 (29.6) (26.7–32.1)
Child’s origin	Foreign (n=77)	26 (33.8) (23.2–44.3)	OR: 1.04 (0.64–1.68)
	Spanish (n=1799)	591 (32.8) (30.8–35.1)
Mother’s origin	Foreign (n=387)	115 (29.7) (25.2–34.3)	OR: 0.83 (0.65–1.05)
	Spanish (n=1489)	502 (33.7) (31.4–36.2)
Father’s origin	Foreign (n=357)	123 (34.5) (29.5–39.4)	OR: 1.09 (0.85–1.38)
	Spanish (n=1519)	494 (32.5) (30.3–35.0)
Number of siblings	Colonized	2.00 (0.98)	MD: 0.03 (−0.07–0.13)
	Not colonized	1.97 (1.01)
People per household	Colonized	4.03 (0.95)	MD: 0.03 (−0.06–0.12)
	Not colonized	4.00 (1.01)
Habitat	Urban (n=1580)	538 (34) (31.7–36.4)	OR urban: 1.37 (1.03–1.81)*
	Rural (n=296)	81 (27.4) (22.3–32.4)
Livestock exposure	Yes (n=192)	66 (34.4) (27.7–44.1)	OR: 1.07 (0.78–1.47)
	No (n=1679)	553 (32.9) (30.6–35.1)
Pets at home	Yes (n=867)	282 (32.5) (29.4–35.6)	OR: 0.97 (0.80–1.18)
	No (n=1002)	333 (33.2) (30.3–36.2)
School/daycare attendance	Yes (n=1539)	551 (35.8) (33.4–38.2)	OR 2.19 (1.65–2.92)*
	No (n=336)	68 (20.2) (16.0–24.5)
Previous antibiotic treatment	Yes (n=105)	28 (56.7) (18.2–35.1)	OR no antibiotic: 1.38 (0.88–2.15)
	No (n=1761)	588 (33.4) (31.2–35.6)
Previous skin infection	Yes (n=361)	136 (37.7) (32.8–42.8)	OR: 1.29 (1.01–1.63)*
	No (n=1418)	455 (32,1) (29.7–34.6)
Hospital admission last year	Yes (n=97)	26 (26.8) (18.0–35.6)	OR: 1.36 (0.86–2.16)
	No (n=1774)	591 (33.3) (31.1–35.5)
Underlying chronic disease	Yes (n=633)	242 (38.2) (34.7–42.3)	OR: 1.44 (1.18–1.76)*
	No (n=1240)	375 (30.2) (27.7–32.8)
MULTIVARIATE ANALYSIS
Age			OR: 1.10 (1.07–1.12)*
Male gender			OR: 1.43 (1.17–1.76)*
Urban habitat			OR: 1.46 (1.08–1.97)*
Underlying chronic disease			OR: 1.27 (1.02–1.57)*

Note: *Significant results are represented in bold letters.

Abbreviations: SD, standard deviation; MD, mean difference; OR, odds ratio; CI, confidence interval.

Figure 1 Antibiotic susceptibility results of methicillin-susceptible S. aureus (A) and methicillin-resistant strains (B).