1. Methicillin-Resistant Staphylococcus aureus Infections in California Hospital Patients, 1999 – 2006 Mary Tran, PhD, MPH Niya Fong, BS Microbiology California Office of Statewide Health Planning and Development October 2008

2. Slide 2 APHA Annual Meeting October 2008 Presenter Disclosures (1)The following personal financial relationships with commercial interests relevant to this presentation existed during the past 12 months: Mary Nelson Tran, PhD, MPH “No relationships to disclose”

3. Slide 3 APHA Annual Meeting October 2008 Issues Steep increase in MRSA rates in US hospital and long-term care patients. –Healthcare-associated MRSA (HA-MRSA) Evidence that MRSA is also spreading into the community (schools, gymnasiums) –Community-acquired MRSA (CA-MRSA) Some evidence that patients with MRSA infections cost more to treat and have higher mortality rates compared with non-resistant S.aureus infections.

4. Slide 4 APHA Annual Meeting October 2008 Methods Data source: –Hospital Patient Discharge Data, 1999, 2001, 2003, 2005, 2006. Definition of MRSA infection: –S. aureus infection in any diagnosis field of the PDD record: Three ICD-9 codes are specific for S. aureus: –038.11 = S. aureus septicemia –482.41 = S. aureus pneumonia –041.11 = S. aureus infection in conditions classified elsewhere or of unspecified site –Methicillin resistance: ICD-9 code = V09.0 in any secondary diagnosis field (1-24) –MRSA Rate: % S. aureus infection cases that are resistant =(MRSA / all S. aureus infections) * 100 Statistical analyses by SAS, ver. 9.1 Maps by ArcView

5. Slide 5 APHA Annual Meeting October 2008 Comparison of National MRSA Rates* with California Rates** *Klein, et al, Emerg Inf Dis, Dec. 2007:13(12)1840-46. **Authors’ analysis

6. Slide 6 APHA Annual Meeting October 2008 Volume of Hospitalizations with S. aureus Infection, by Resistance Type. California, 1999-2006

7. Slide 7 APHA Annual Meeting October 2008 Hospital MRSA Rates by Age Group. California, 1999-2006

8. Slide 8 APHA Annual Meeting October 2008 Hospital MRSA Rates by Source of Admission. California, 1999-2006

9. Slide 9 APHA Annual Meeting October 2008 Percent of S. aureus Infections Reported as MRSA for Hospital Patients, California 1999 and 2006

10. Slide 10 APHA Annual Meeting October 2008 Trends in Length of Stay per Hospitalization, by Infection Type. California, 1999-2006

11. Slide 11 APHA Annual Meeting October 2008 Trends in Percent of Cases Discharged to Skilled Nursing and to Home, by Infection Type. California, 1999-2006

12. Slide 12 APHA Annual Meeting October 2008 Trends in the Percent Died In-Hospital, by Infection Type. California, 1999-2006

13. Slide 13 APHA Annual Meeting October 2008 Trends in Total and Daily Charges per Hospitalization, by Infection Type. California, 1999-2006

14. Slide 14 APHA Annual Meeting October 2008 Limitations This report is a conservative estimate of the volume and rate of MRSA infection in California. –Only hospitalized cases are included. –Only S. aureus cases that were tested for antibiotic resistance and reported as resistant could be counted as MRSA. Cases reported as “admissions from home” may include patients recently discharged from a hospital or long term care facility. These MRSA infections may or may not be cases of Healthcare Acquired Infections (HAI). The discharge records do not include sufficient information to identify which cases are HAI.

15. Slide 15 APHA Annual Meeting October 2008 Conclusions California MRSA rate was lower than the overall US rate in 1999, but surpassed it around 2003. –Hospital MRSA rate has risen in almost all counties Highest MRSA rates are found in patients who are: –Seniors and admissions from SNFs –But rates in other groups are catching up. For MRSA cases, in-hospital mortality and charges for care are declining. –Both trends may be related to MRSA patients’ shortened length of stay. MRSA rates for admissions from home are rising. –Does this indicate rising prevalence of Community-Acquired MRSA? Rates of MRSA discharges to home are rising. –Is there increased risk of spread of MRSA into the community?

16. Slide 16 APHA Annual Meeting October 2008 Acknowledgements Niya Fong: SAS analyses Charlene Parham: Maps of MRSA rates MRSA electron micrograph. CDC/Janice Carr. http://www.cdc.gov/ncidod/dhqp/ar_MRSA_spotlight_2006.html.

17. Slide 17 APHA Annual Meeting October 2008 Questions