Prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in the community pediatric population.
BACKGROUND
Reports from various geographic regions indicate that the prevalence of community-acquired methicillin-resistant (MRSA) infection is increasing. The primary reservoir is the anterior nares; nasal carriage is a risk factor for infection in a variety of populations. Little is known about MRSA nasal carriage rates among children in Nashville, TN and the associated likelihood of community MRSA transmission.


METHODS
Nasal swabs were collected from 500 children at well-child visits at either a university hospital pediatric clinic or a private pediatric office. Cultures were plated onto selective staphylococcal media, with or without oxacillin. isolates were confirmed by coagulase tube testing. Antibiotic susceptibilities were determined for suspected methicillin-resistant isolates by standard broth microdilution methods (National Committee for Clinical Laboratory Standards). Pulsed field gel electrophoresis was used to evaluate epidemiologic relatedness. PCR testing was done to assess for the gene. A parent questionnaire was administered regarding MRSA risk factors.


RESULTS
Four patients had oxacillin-resistant isolates (MIC >or= 4 microg/ml), and two had borderline resistant isolates (MICs = 1 and 2 microg/ml). One of the borderline-resistant isolates and one of the MRSA isolates had pulsed field gel electrophoresis typing results indicating close relatedness. The gene was present in all resistant isolates and one of the borderline-resistant isolates. Only having a household member employed in a hospital was associated with a greater risk of MRSA nasal carriage (odds ratio, 9.6; P= 0.008).


CONCLUSIONS
MRSA nasal colonization is present within Nashville's healthy pediatric population. Children with household contacts employed in a hospital are significantly more likely to be colonized.
Nakamura
Mari M
MM
Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Nashville, TN, USA.
Rohling
Kasey L
KL
Shashaty
Michael
M
Lu
Hongzhou
H
Tang
Yi-Wei
YW
Edwards
Kathryn M
KM
D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D009305:Nasopharynx / Q000382:microbiology*; D015995:Prevalence; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*; D013714:Tennessee / Q000453:epidemiology; D014505:Urban Population
D000900:Anti-Bacterial Agents