Impact of screening for MRSA carriers at hospital admission on risk-adjusted indicators according to the imported MRSA colonization pressure.
We evaluated the impact of the different components of a screening programme of methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission on the value of two risk-adjusted rates: the proportion of imported MRSA and an indicator of the MRSA colonization pressure (ICP), and the incidence of MRSA acquired and detected in our hospital. Indicators were calculated: (1) with no screening programme; (2) with a programme limited to the intensive care unit (ICU); (3) with a programme extended to patients with risk factors for MRSA carriage hospitalized in non-ICU wards. The programme included an automatic alert. Systematic sampling of patients with risk factors hospitalized in non-ICU settings detected nearly 50% of carriers at admission. The proportion of MRSA imported into our hospital varied from 35.4% without any screening programme to 71.8% when all components of our screening programme were considered (P<10(-4)). The ICP varied from 3.1% (31/985) with the complete programme to 10.4% (31/297) without any screening programme (P<10(-6)). Screening patients with risk factors for MRSA carriage hospitalized in non-ICU wards resulted in a 51% increase of the calculated proportion of imported strains and a 58% decrease of the ICP. The two studied indicators were strongly dependent on the screening strategy for MRSA carriers implemented at admission. The screening strategy for patients admitted to non-ICU wards who have risk factors for MRSA carriage seems to be the determinant for the interpretation of certain risk-adjusted indicators of MRSA cross-transmission. Comparisons of these indicators must consider the setting in which the screening programmes are implemented.
Eveillard
M
M
Department of Microbiology and Hygiene, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, 178 rue des Renouillers, F92700 Colombes Cedex, France. mathieu.eveillard@lmr.ap-hop-paris.fr
Lancien
E
E
Barnaud
G
G
Hidri
N
N
Gaba
S
S
Benlolo
J A
JA
Joly-Guillou
M-L
ML
D002353:Carrier State; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D005602:France / Q000453:epidemiology; D006757:Hospital Units / Q000706:statistics & numerical data; D006784:Hospitals, Teaching; D006801:Humans; D017053:Infection Control / Q000379:methods*; D007362:Intensive Care Units; D008403:Mass Screening; D016106:Methicillin Resistance; D017063:Outcome Assessment, Health Care; D010343:Patient Admission; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018571:Sentinel Surveillance; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000302:isolation & purification*