147000 Retrospective study of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in a west Texas community, 2004

Monday, November 5, 2007: 11:05 AM

J. Rush Pierce Jr., MD, MPH , Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX
Alicia E.I. Pittard, BA , Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX
Anne V. Denison, RN, BSN, MS , Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX
Susan K. Strickland, RN, BSN , Department of Public Health, City of Amarillo, Amarillo, TX
Amanda Arellano , Department of Public Health, City of Amarillo, Amarillo, TX
Matthew Whinery, BS , Department of Public Health, City of Amarillo, Amarillo, TX
J. Matthew Richardson, MPH , Department of Public Health, City of Amarillo, Amarillo, TX
        
Background. MRSA infections have traditionally occurred in hospitalized patients or those receiving medical interventions. Recently MRSA infections have occurred in persons without these hospital-associated risk factors. This study examines these CA-MRSA infections in a two county area with a population of 200,000.

Methods. We reviewed all MRSA cultures from Amarillo hospital laboratories obtained in 2004. We then reviewed medical records to exclude patients with hospital-associated risk factors. Remaining patients were interviewed to further exclude hospital-associated cases, and to ascertain clinical features of their disease.

Results. Of approximately 1100 MRSA cases in 2004, 289 had probable CA-MRSA infection. Of the 142 cases which were interviewed, 132 had confirmed CA-MRSA. Among CA-MRSA cases children and Hispanics were underrepresented (19% of cases were children vs. 29% of the population; 12% of cases were Hispanic vs. 22% of the population). At least 42% of confirmed CA-MRSA infections took longer than 4 weeks to resolve and 7% were recurrent. Almost all patients (96%) with confirmed CA-MRSA had skin or soft tissue infections. Of these, 41% were mistaken for a spider bite by the patient and/or the physician. Over 95% of the CA-MRSA infections were sensitive to rifampin, tetracycline, and trimethoprim-sulfamethoxazole . Clindamycin resistance was seen in 15% and fluoroquinilone resistance in 50%. A significant proportion (43%) reported exposure to someone with a Staph infection. Most patients (80%) were not familiar with MRSA.

Conclusions. CA-MRSA has become a serious and common illness in our community, and has major public health implications.

Learning Objectives:
1. List three ways that CA-MRSA skin and soft tissue infections look differently than usual skin and soft tissue infections with Staph aureus. 2. Articulate why CA-MRSA skin and soft tissue infections are frequently mistaken for spider bites. 3. Describe three reasons why CA-MRSA is an important public health problem.

Keywords: Emerging Diseases, Infectious Diseases

Presenting author's disclosure statement:

Any relevant financial relationships? No
Any institutionally-contracted trials related to this submission?

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

See more of: Infectious Disease Epidemiology
See more of: Epidemiology