title: Risk factors for household transmission of community-associated methicillin-resistant Staphylococcus aureus.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a community pathogen. Community-associated (CA) MRSA infections have occurred among multiple members of a household. We describe the incidence of and risk factors for MRSA colonization among household contacts of children with CA-MRSA infections.
  
  
  METHODS
  MRSA-infected children <18 years of age who lacked established healthcare-associated MRSA risk factors were identified through surveillance at 12 Minnesota hospital laboratories. Nasal swab specimens and information on medical history and hygiene behaviors were collected from case-patients and enrolled household contacts during home visits. S. aureus isolates obtained from nasal cultures were screened for oxacillin resistance.
  
  
  RESULTS
  In all, 236 households consisting of 236 case-patients and 712 household contacts were enrolled. Home visits were conducted on an average of 69 days after the onset of symptom in case-patients (range: 16-178 days). Twenty-nine (13%) case-patients and 82 (12%) household contacts had MRSA nasal colonization. Nasal MRSA colonization in ≥ 1 household contact occurred in 58 (25%) households. Household contacts who assisted the case-patient to bathe or who shared balms/ointments/lotion with the case-patient were more likely to be colonized (P < 0.01, P < 0.05), whereas those who reported using antibacterial versus nonantibacterial soap for hand washing were less likely to be colonized (P < 0.05) with MRSA clonally related to the case-patient infection isolate.
  
  
  CONCLUSIONS
  Only 13% of case-patients had MRSA nasal colonization on an average of 69 days after their initial MRSA infection. CA-MRSA colonization may be short-lived or may occur at non-nasal sites. One quarter of households had at least one household contact colonized with MRSA. Modifiable behaviors, such as sharing personal items, may contribute to transmission.
authors: Minnesota Department of Health, Infectious Disease Epidemiology Prevention and Control Section, St. Paul, MN 55164, USA. jessica.nerby@allina.com
authors: Jessica M
authors: JM
authors: Nerby
authors: Rachel
authors: R
authors: Gorwitz
authors: Lindsey
authors: L
authors: Lesher
authors: Billie
authors: B
authors: Juni
authors: Selina
authors: S
authors: Jawahir
authors: Ruth
authors: R
authors: Lynfield
authors: Kathleen
authors: K
authors: Harriman