373. Transmission of Staphylococcus Aureus among the Households of CA-MRSA Infected Cases: a Pooled Analysis of Primary Data from 3 Studies across International Settings
Session: Poster Abstract Session: MRSA, MSSA, Enterococci
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • IDWeek Poster 130924 PDF.pdf (616.7 kB)
  • Background:

    While the household (HH) is a recognized reservoir for community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA), there is limited understanding of how it spreads among people within HHs. We compared CA-MRSA HH transmission using pooled primary data from 3 similar studies conducted in New York, US, Breda, NL, and Melbourne, AU.

    Methods:

    In all 3 studies, following CA-MRSA infection of the index, HH members answered a questionnaire and nasal swabs were collected during a home visit. Swabs positive for SA were genotyped by spa-sequencing, PFGE or MLST. HH transmission of the clinical isolate was defined as colonization of a non-index HH member with the same spa- or PFGE-type as the index. HH transmission of all SA was defined as ≥2 HH members colonized with the same spa- or PFGE-type or HH transmission of the clinical isolate.

    Results:

    Study sites differed by predominant clinical strain, strain type variability (see figure 1) and by multiple variables (see table 1). When comparing HH transmission in multivariate models, the index being colonized with the clinical isolate at the time of the home visit and the percentage of children <18 years in the HH were independently associated with HH transmission of the clinical strain (see figure 2) and with HH transmission of all SA (see figure 3).

    Conclusion:

    Pooled data from 3 international studies revealed common risk factors for CA-MRSA HH transmission. The percentage of children in the HH is a risk for SA spread. These findings suggest that decolonization strategies could be used across diverse geographic settings to limit HH transmission of CA-MRSA.


    Table 1: Comparison of HH characteristics and transmission by study site

    Total (N= 296)

    US (N= 139)

    NL (N= 61)

    AU (N= 96)

    median

    IQR

    median

    IQR

    median

    IQR

    median

    IQR

    p

    HH size

    3

    2-5

    4

    3-5

    2

    2-4

    3

    2-4

    <.001

    Percentage of children <18 in HH

    25

    0-50

    33

    33-50

    0

    0-50

    0

    0-50

    <.001

    N

    %

    N

    %

    N

    %

    N

    %

    p

    Index male

    131

    44

    51

    37

    29

    48

    51

    53

    0.04

    Index <18 years

    70

    24

    41

    29

    9

    15

    20

    21

    0.06

    Index colonized with clinical isolate

    81

    27

    21

    15

    37

    61

    23

    24

    <.001

    Any HH member colonized with MRSA

    115

    39

    52

    37

    25

    41

    38

    40

    0.88

    HH transmission of clinical isolate

    67

    23

    37

    27

    13

    21

    17

    18

    0.27

    HH transmission of all SA

    96

    32

    55

    40

    15

    25

    26

    27

    0.04

    Justin Knox, MPH1, Miranda van Rijen2, Anne-Catrin Uhlemann, MD, PhD1, Cory Hafer1, Glenny Vasquez3, Peter Vavagiakis4, Qiuhu Shi, PhD5, Paul Johnson, MBBS, FRACP, PhD6, Geoffrey Coombs, BApplSc PGDip(Biomed)7, Marjolein Kluytmans - Van Den Bergh2, Jan Kluytmans, MD, PhD8, Catherine Bennett, BSc(Hons), MApplEpid, PhD9 and Franklin Lowy, MD10, (1)Columbia University Medical Center, New York, NY, (2)Amphia Hospital, Breda, Netherlands, (3)Columbia University Medical Center, NY, NY, (4)Panna Tech, Brooklyn, NY, (5)New York Medical College, Valhalla, NY, (6)Austin Hospital, Heidelberg, Australia, (7)PathWest Laboratory Medicine - WA, Perth, Western Australia, Australia, (8)Amphia Hospital Breda, Breda, Netherlands, (9)The University of Melbourne, Melbourne, Australia, (10)Columbia University, New York, NY

    Disclosures:

    J. Knox, None

    M. van Rijen, None

    A. C. Uhlemann, None

    C. Hafer, None

    G. Vasquez, None

    P. Vavagiakis, None

    Q. Shi, None

    P. Johnson, None

    G. Coombs, None

    M. Kluytmans - Van Den Bergh, None

    J. Kluytmans, None

    C. Bennett, None

    F. Lowy, None

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