Association between carriage of Streptococcus pneumoniae and Staphylococcus aureus in Children.
BACKGROUND
Widespread pneumococcal conjugate vaccination may bring about epidemiologic changes in upper respiratory tract flora of children. Of particular significance may be an interaction between Streptococcus pneumoniae and Staphylococcus aureus, in view of the recent emergence of community-acquired methicillin-resistant S aureus.


OBJECTIVE
To examine the prevalence and risk factors of carriage of S pneumoniae and S aureus in the prevaccination era in young children.


METHODS
Cross-sectional surveillance study of nasopharyngeal carriage of S pneumoniae and nasal carriage of S aureus by 790 children aged 40 months or younger seen at primary care clinics in central Israel during February 2002.


METHODS
Carriage rates of S pneumoniae (by serotype) and S aureus; risk factors associated with carriage of each pathogen.


RESULTS
Among 790 children screened, 43% carried S pneumoniae and 10% carried S aureus. Staphylococcus aureus carriage among S pneumoniae carriers was 6.5% vs 12.9% in S pneumoniae noncarriers. Streptococcus pneumoniae carriage among S aureus carriers was 27.5% vs 44.8% in S aureus noncarriers. Only 2.8% carried both pathogens concomitantly vs 4.3% expected dual carriage (P =.03). Risk factors for S pneumoniae carriage (attending day care, having young siblings, and age older than 3 months) were negatively associated with S aureus carriage.


CONCLUSIONS
Streptococcus pneumoniae carriage, specifically of vaccine-type strains, is negatively associated with S aureus carriage in children. The implications of these findings in the pneumococcal vaccine era require further investigation.
Regev-Yochay
Gili
G
Sheba Medical Center, Tel Hashomer, Israel. gili.regev@sheba.health.gov.il
Dagan
Ron
R
Raz
Meir
M
Carmeli
Yehuda
Y
Shainberg
Bracha
B
Derazne
Estela
E
Rahav
Galia
G
Rubinstein
Ethan
E
D002353:Carrier State / Q000453:epidemiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007557:Israel / Q000453:epidemiology; D009305:Nasopharynx / Q000382:microbiology*; D015995:Prevalence; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D013290:Streptococcal Infections / Q000453:epidemiology*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*