Nasal carriage of Staphylococcus aureus and methicillin-resistant S aureus in the United States, 2001-2002.
OBJECTIVE
Staphylococcus aureus is a common cause of invasive infections, yet most assessments of prevalence are based on health care-based samples. We computed population-based estimates of nasal carriage of S aureus and risk factors for carriage, as well as population-based estimates of nasal carriage of methicillin-resistant S aureus (MRSA).


METHODS
We used the National Health and Nutrition Examination Survey (NHANES) 2001-2002 to estimate carriage of S aureus and MRSA for the non-institutionalized US population including children and adults.


RESULTS
An estimated 86.9 million persons (32.40% of the population) were colonized with S aureus. The prevalence of MRSA among S aureus isolates was 2.58%, for an estimated population carriage of MRSA of 0.84% or 2.2 million persons. Among individuals with S aureus isolates, individuals aged 65 years or older had the highest MRSA prevalence (8.28%). Among all the racial/ethnic groups studied, Hispanics had the highest prevalence of colonization with S aureus but, when colonized, were less likely to have MRSA.


CONCLUSIONS
This first nationally representative assessment of carriage of S aureus indicates that nearly one third of the population is currently colonized by this organism. Although the prevalence of MRSA remains low, more than 2.2 million people carry this resistant organism; thus, vigilance in promoting appropriate microbial transmission protocols should remain a priority.
Mainous
Arch G
AG
Department of Family Medicine, Medical University of South Carolina, Charleston 29425, USA. mainouag@musc.edu
Hueston
William J
WJ
Everett
Charles J
CJ
Diaz
Vanessa A
VA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002353:Carrier State; D002648:Child; D002675:Child, Preschool; D005260:Female; D006306:Health Surveys; D006801:Humans; D007223:Infant; D008297:Male; D016106:Methicillin Resistance / Q000208:ethnology; D008875:Middle Aged; D009296:Nasal Cavity / Q000382:microbiology; D012307:Risk Factors; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity; D014481:United States / Q000453:epidemiology