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Detailed contact data and the dissemination of Staphylococcus aureus in hospitals.

Obadia T, Silhol R, Opatowski L, Temime L, Legrand J, Thiébaut AC, Herrmann JL, Fleury É, Guillemot D, Boëlle PY, I-Bird Study Gro - PLoS Comput. Biol. (2015)

Bottom Line: In the broad diversity of isolated S. aureus strains, 173 transmission events were observed between participants.Additional analyses revealed a higher dissemination risk between patients via healthcare workers than via other patients.In conclusion, S. aureus transmission was consistent with contacts defined by electronically collected CPIs, illustrating their potential as a tool to control hospital-acquired infections and help direct surveillance.

View Article: PubMed Central - PubMed

Affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France; INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France.

ABSTRACT
Close proximity interactions (CPIs) measured by wireless electronic devices are increasingly used in epidemiological models. However, no evidence supports that electronically collected CPIs inform on the contacts leading to transmission. Here, we analyzed Staphylococcus aureus carriage and CPIs recorded simultaneously in a long-term care facility for 4 months in 329 patients and 261 healthcare workers to test this hypothesis. In the broad diversity of isolated S. aureus strains, 173 transmission events were observed between participants. The joint analysis of carriage and CPIs showed that CPI paths linking incident cases to other individuals carrying the same strain (i.e. possible infectors) had fewer intermediaries than predicted by chance (P < 0.001), a feature that simulations showed to be the signature of transmission along CPIs. Additional analyses revealed a higher dissemination risk between patients via healthcare workers than via other patients. In conclusion, S. aureus transmission was consistent with contacts defined by electronically collected CPIs, illustrating their potential as a tool to control hospital-acquired infections and help direct surveillance.

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Related in: MedlinePlus

CPI supported transmitters.(Top) CPI-supported transmitters were selected among carriers of the same strain (green) as the incident case (yellow) who were the closest in the CPI network. Here, P1 and H1 are two CPI-supported transmitters in the incident case’s 2-hop neighborhood, but not P2 who is further away (3-hop neighborhood). Patients are shown as triangles and HCWs as diamonds. (Bottom left) Comparison of the distance distribution between CPI-supported transmitters and incident cases in the data (black) and with random permutations of carriage data (white) in the simulation study. (Bottom right) Comparison of the distance between CPI-supported transmitters and incident cases in the original data.
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pcbi.1004170.g003: CPI supported transmitters.(Top) CPI-supported transmitters were selected among carriers of the same strain (green) as the incident case (yellow) who were the closest in the CPI network. Here, P1 and H1 are two CPI-supported transmitters in the incident case’s 2-hop neighborhood, but not P2 who is further away (3-hop neighborhood). Patients are shown as triangles and HCWs as diamonds. (Bottom left) Comparison of the distance distribution between CPI-supported transmitters and incident cases in the data (black) and with random permutations of carriage data (white) in the simulation study. (Bottom right) Comparison of the distance between CPI-supported transmitters and incident cases in the original data.

Mentions: We investigated all 153 incident colonization episodes detected from longitudinal swab data. As expected from the simulations, a CPI path existed between the candidate transmitter and the incident case in almost all instances (97%, Table 3). The characteristics of the shortest CPI paths lengths from candidate transmitter to incident case were in favor of transmission along CPIs, with shorter paths in the original data than after random permutations (Fig. 3, Strategy S3: P < 0.001). This was therefore the sign that S. aureus transmissions detected from the I-Bird swabs were driven by CPIs.


Detailed contact data and the dissemination of Staphylococcus aureus in hospitals.

Obadia T, Silhol R, Opatowski L, Temime L, Legrand J, Thiébaut AC, Herrmann JL, Fleury É, Guillemot D, Boëlle PY, I-Bird Study Gro - PLoS Comput. Biol. (2015)

CPI supported transmitters.(Top) CPI-supported transmitters were selected among carriers of the same strain (green) as the incident case (yellow) who were the closest in the CPI network. Here, P1 and H1 are two CPI-supported transmitters in the incident case’s 2-hop neighborhood, but not P2 who is further away (3-hop neighborhood). Patients are shown as triangles and HCWs as diamonds. (Bottom left) Comparison of the distance distribution between CPI-supported transmitters and incident cases in the data (black) and with random permutations of carriage data (white) in the simulation study. (Bottom right) Comparison of the distance between CPI-supported transmitters and incident cases in the original data.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4366219&req=5

pcbi.1004170.g003: CPI supported transmitters.(Top) CPI-supported transmitters were selected among carriers of the same strain (green) as the incident case (yellow) who were the closest in the CPI network. Here, P1 and H1 are two CPI-supported transmitters in the incident case’s 2-hop neighborhood, but not P2 who is further away (3-hop neighborhood). Patients are shown as triangles and HCWs as diamonds. (Bottom left) Comparison of the distance distribution between CPI-supported transmitters and incident cases in the data (black) and with random permutations of carriage data (white) in the simulation study. (Bottom right) Comparison of the distance between CPI-supported transmitters and incident cases in the original data.
Mentions: We investigated all 153 incident colonization episodes detected from longitudinal swab data. As expected from the simulations, a CPI path existed between the candidate transmitter and the incident case in almost all instances (97%, Table 3). The characteristics of the shortest CPI paths lengths from candidate transmitter to incident case were in favor of transmission along CPIs, with shorter paths in the original data than after random permutations (Fig. 3, Strategy S3: P < 0.001). This was therefore the sign that S. aureus transmissions detected from the I-Bird swabs were driven by CPIs.

Bottom Line: In the broad diversity of isolated S. aureus strains, 173 transmission events were observed between participants.Additional analyses revealed a higher dissemination risk between patients via healthcare workers than via other patients.In conclusion, S. aureus transmission was consistent with contacts defined by electronically collected CPIs, illustrating their potential as a tool to control hospital-acquired infections and help direct surveillance.

View Article: PubMed Central - PubMed

Affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France; INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France.

ABSTRACT
Close proximity interactions (CPIs) measured by wireless electronic devices are increasingly used in epidemiological models. However, no evidence supports that electronically collected CPIs inform on the contacts leading to transmission. Here, we analyzed Staphylococcus aureus carriage and CPIs recorded simultaneously in a long-term care facility for 4 months in 329 patients and 261 healthcare workers to test this hypothesis. In the broad diversity of isolated S. aureus strains, 173 transmission events were observed between participants. The joint analysis of carriage and CPIs showed that CPI paths linking incident cases to other individuals carrying the same strain (i.e. possible infectors) had fewer intermediaries than predicted by chance (P < 0.001), a feature that simulations showed to be the signature of transmission along CPIs. Additional analyses revealed a higher dissemination risk between patients via healthcare workers than via other patients. In conclusion, S. aureus transmission was consistent with contacts defined by electronically collected CPIs, illustrating their potential as a tool to control hospital-acquired infections and help direct surveillance.

Show MeSH
Related in: MedlinePlus