MRSA Surveillance, Decolonization, Isolation Work at 4 Years

Major Finding: Prevalence of MRSA infection at NorthShore University HealthSystem dropped from a baseline of 8.9 per 10,000 patient-days to 3.3 per 10,000 at 4 years after universal MRSA surveillance with decolonization and contact isolation of those found to be colonized.

Data Source: Observational 4-year study done at a three-hospital, 850-bed health organization.

Disclosures: Dr. Peterson has received research grants from and/or consulted for Cepheid, NorthShore, BD-GeneOhm, MicroPhage, Nanosphere, the National Institute for Allergy and Infectious Diseases, Roche, 3M, and Washington Square Health Foundation, mainly in the area of new test development.

ATLANTA — Universal admission surveillance for methicillin-resistant Staphylococcus aureus at three Illinois hospitals significantly reduced both MRSA and overall S. aureus infection over a 4-year period.

The observational study findings are an expansion of 21-month data that showed reductions of MRSA infection from 8.9/10,000 patient-days at baseline to 3.9/10,000 with universal MRSA real-time polymerase chain reaction–based nasal surveillance followed by topical decolonization and contact isolation of patients who test positive (Ann. Intern. Med. 2008;148:409–18).

The update included data from the baseline period, all intensive care unit admissions for 1 year, and all hospital admissions for 4 years with universal MRSA surveillance at the three-hospital, 850-bed NorthShore University HealthSystem, which averages 40,000 annual admissions. One-year ICU prevalence, reported previously, was 7.4/10,000 patient-days, and the prevalence after 4 years with universal surveillance was 3.3/10,000, Dr. Lance R. Peterson said at the Decennial International Conference on Healthcare-Associated Infections.

The prevalence density of MRSA decreased at each of the four body sites assessed—bloodstream, respiratory, urinary tract, and surgical site—in each of the time periods, said Dr. Peterson, of NorthShore University HealthSystem, Evanston, Ill.

The percentage of exogenous MRSA fell over the 4 years from 48% to 33%, implying fewer patients were acquiring MRSA in the hospital. Over the same period, there was a 70% reduction in total MRSA disease during hospitalization and at 30 days post hospitalization. The proportion of all S. aureus infections that were methicillin-resistant also declined significantly, from 52% at baseline to 31% at 4 years, Dr. Peterson reported.

Based on a previous cost analysis of 178 MRSA cases and 5,796 controls, the excess expense of MRSA infection was estimated at $24,000, compared with no infection. During the first 4 years of NorthShore's containment program, 406 MRSA infections and 72 deaths were avoided, with a net expense reduction of $8.8 million, he said.

Previous studies have suggested that the success of a MRSA surveillance program depends on disease/colonization prevalence, scope of surveillance, test sensitivity, rapidity of results reporting, and length of the intervention period. The cost-benefit ratio of any program depends on the degree to which it is successful, Dr. Peterson said.

“If you implement a MRSA control program that includes surveillance and there is no desired impact, you may need to do more, such as expand the population tested or increase the sensitivity and speed of testing,” he noted.

The role of adding decolonization in the acute care setting is still unclear, he said. In this study, mupirocin and chlorhexidine decolonization in patients testing positive did not affect the risk of eventual disease, although it did appear to prolong the median number of days to develop infection, from 15.5 days to 50 days. Mupirocin resistance is now at 10%, however, which “is certainly a challenge we'll have to deal with as we go forward,” he concluded.

Major Finding: Prevalence of MRSA infection at NorthShore University HealthSystem dropped from a baseline of 8.9 per 10,000 patient-days to 3.3 per 10,000 at 4 years after universal MRSA surveillance with decolonization and contact isolation of those found to be colonized.

Data Source: Observational 4-year study done at a three-hospital, 850-bed health organization.

Disclosures: Dr. Peterson has received research grants from and/or consulted for Cepheid, NorthShore, BD-GeneOhm, MicroPhage, Nanosphere, the National Institute for Allergy and Infectious Diseases, Roche, 3M, and Washington Square Health Foundation, mainly in the area of new test development.

ATLANTA — Universal admission surveillance for methicillin-resistant Staphylococcus aureus at three Illinois hospitals significantly reduced both MRSA and overall S. aureus infection over a 4-year period.

The observational study findings are an expansion of 21-month data that showed reductions of MRSA infection from 8.9/10,000 patient-days at baseline to 3.9/10,000 with universal MRSA real-time polymerase chain reaction–based nasal surveillance followed by topical decolonization and contact isolation of patients who test positive (Ann. Intern. Med. 2008;148:409–18).

The update included data from the baseline period, all intensive care unit admissions for 1 year, and all hospital admissions for 4 years with universal MRSA surveillance at the three-hospital, 850-bed NorthShore University HealthSystem, which averages 40,000 annual admissions. One-year ICU prevalence, reported previously, was 7.4/10,000 patient-days, and the prevalence after 4 years with universal surveillance was 3.3/10,000, Dr. Lance R. Peterson said at the Decennial International Conference on Healthcare-Associated Infections.

The prevalence density of MRSA decreased at each of the four body sites assessed—bloodstream, respiratory, urinary tract, and surgical site—in each of the time periods, said Dr. Peterson, of NorthShore University HealthSystem, Evanston, Ill.

The percentage of exogenous MRSA fell over the 4 years from 48% to 33%, implying fewer patients were acquiring MRSA in the hospital. Over the same period, there was a 70% reduction in total MRSA disease during hospitalization and at 30 days post hospitalization. The proportion of all S. aureus infections that were methicillin-resistant also declined significantly, from 52% at baseline to 31% at 4 years, Dr. Peterson reported.

Based on a previous cost analysis of 178 MRSA cases and 5,796 controls, the excess expense of MRSA infection was estimated at $24,000, compared with no infection. During the first 4 years of NorthShore's containment program, 406 MRSA infections and 72 deaths were avoided, with a net expense reduction of $8.8 million, he said.

Previous studies have suggested that the success of a MRSA surveillance program depends on disease/colonization prevalence, scope of surveillance, test sensitivity, rapidity of results reporting, and length of the intervention period. The cost-benefit ratio of any program depends on the degree to which it is successful, Dr. Peterson said.

“If you implement a MRSA control program that includes surveillance and there is no desired impact, you may need to do more, such as expand the population tested or increase the sensitivity and speed of testing,” he noted.

The role of adding decolonization in the acute care setting is still unclear, he said. In this study, mupirocin and chlorhexidine decolonization in patients testing positive did not affect the risk of eventual disease, although it did appear to prolong the median number of days to develop infection, from 15.5 days to 50 days. Mupirocin resistance is now at 10%, however, which “is certainly a challenge we'll have to deal with as we go forward,” he concluded.

Major Finding: Prevalence of MRSA infection at NorthShore University HealthSystem dropped from a baseline of 8.9 per 10,000 patient-days to 3.3 per 10,000 at 4 years after universal MRSA surveillance with decolonization and contact isolation of those found to be colonized.

Data Source: Observational 4-year study done at a three-hospital, 850-bed health organization.

Disclosures: Dr. Peterson has received research grants from and/or consulted for Cepheid, NorthShore, BD-GeneOhm, MicroPhage, Nanosphere, the National Institute for Allergy and Infectious Diseases, Roche, 3M, and Washington Square Health Foundation, mainly in the area of new test development.

ATLANTA — Universal admission surveillance for methicillin-resistant Staphylococcus aureus at three Illinois hospitals significantly reduced both MRSA and overall S. aureus infection over a 4-year period.

The observational study findings are an expansion of 21-month data that showed reductions of MRSA infection from 8.9/10,000 patient-days at baseline to 3.9/10,000 with universal MRSA real-time polymerase chain reaction–based nasal surveillance followed by topical decolonization and contact isolation of patients who test positive (Ann. Intern. Med. 2008;148:409–18).

The update included data from the baseline period, all intensive care unit admissions for 1 year, and all hospital admissions for 4 years with universal MRSA surveillance at the three-hospital, 850-bed NorthShore University HealthSystem, which averages 40,000 annual admissions. One-year ICU prevalence, reported previously, was 7.4/10,000 patient-days, and the prevalence after 4 years with universal surveillance was 3.3/10,000, Dr. Lance R. Peterson said at the Decennial International Conference on Healthcare-Associated Infections.

The prevalence density of MRSA decreased at each of the four body sites assessed—bloodstream, respiratory, urinary tract, and surgical site—in each of the time periods, said Dr. Peterson, of NorthShore University HealthSystem, Evanston, Ill.

The percentage of exogenous MRSA fell over the 4 years from 48% to 33%, implying fewer patients were acquiring MRSA in the hospital. Over the same period, there was a 70% reduction in total MRSA disease during hospitalization and at 30 days post hospitalization. The proportion of all S. aureus infections that were methicillin-resistant also declined significantly, from 52% at baseline to 31% at 4 years, Dr. Peterson reported.

Based on a previous cost analysis of 178 MRSA cases and 5,796 controls, the excess expense of MRSA infection was estimated at $24,000, compared with no infection. During the first 4 years of NorthShore's containment program, 406 MRSA infections and 72 deaths were avoided, with a net expense reduction of $8.8 million, he said.

Previous studies have suggested that the success of a MRSA surveillance program depends on disease/colonization prevalence, scope of surveillance, test sensitivity, rapidity of results reporting, and length of the intervention period. The cost-benefit ratio of any program depends on the degree to which it is successful, Dr. Peterson said.

“If you implement a MRSA control program that includes surveillance and there is no desired impact, you may need to do more, such as expand the population tested or increase the sensitivity and speed of testing,” he noted.

The role of adding decolonization in the acute care setting is still unclear, he said. In this study, mupirocin and chlorhexidine decolonization in patients testing positive did not affect the risk of eventual disease, although it did appear to prolong the median number of days to develop infection, from 15.5 days to 50 days. Mupirocin resistance is now at 10%, however, which “is certainly a challenge we'll have to deal with as we go forward,” he concluded.