Staphylococcus aureus nasal colonization among pediatric cystic fibrosis patients and their household contacts.
BACKGROUND
Little is known about the prevalence of Staphylococcus aureus nasal colonization and the epidemiology of methicillin-susceptible and methicillin-resistant S. aureus (MRSA) among cystic fibrosis (CF) patients and their household members.


OBJECTIVE
We sought to determine the epidemiology of S. aureus among children and adolescents with CF and their household members.


METHODS
Three CF centers enrolled case subjects with at least 1 MRSA-positive respiratory tract culture from 2001 to 2006 and control subjects with MRSA-negative cultures. S. aureus isolates from the anterior nares of CF subjects and their household members were assessed for staphylococcal chromosomal cassette (SCC) mec type. Strain similarity was determined by pulsed-field gel electrophoresis.


RESULTS
S. aureus nasal colonization occurred in 52.4% (22/42), 27.0% (17/63), and 25.0% (72/288) of case, control, and household participants, respectively. Case subjects and their contacts were more likely to harbor MRSA in their nares and be from a multipatient CF family. Of 31 MRSA strains, 10 (32.3%) were SCCmec type IVa, associated with community-acquisition. Overall, 27.6% of 98 households had > or =2 members colonized with closely related isolates. Household members were equally likely to be colonized with closely related strains of MRSA (20/31, 65%) versus MSSA (38/80, 48%).


CONCLUSIONS
This study demonstrated that household members of CF children harbor both MSSA and MRSA, including CA-MRSA, and that S. aureus is transmitted within CF households. Carriage of S. aureus by household members of CF children may have implications for infection control and treatment strategies. Future studies should monitor the distribution and virulence of SCCmecA types in patients with CF.
Division of Pediatric Pulmonology, Department of Pediatrics, Columbia University, New York, NY, USA. ans9079@med.cornell.edu
Anne
A
Stone
Lynne
L
Quittell
Juyan
J
Zhou
Luis
L
Alba
Meera
M
Bhat
Joan
J
DeCelie-Germana
Sujatha
S
Rajan
Lynn
L
Bonitz
John J
JJ
Welter
Allen J
AJ
Dozor
Ingrid
I
Gherson
Franklin D
FD
Lowy
Lisa
L
Saiman
D000293:Adolescent; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology* / Q000635:transmission; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D003550:Cystic Fibrosis / Q000150:complications*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005191:Family Characteristics; D005192:Family Health; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D009297:Nasal Mucosa / Q000382:microbiology*; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000635:transmission; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
D004269:DNA, Bacterial