During 2002, the Los Angeles County Department of Health Services (LACDHS)
investigated three community outbreaks of skin infections associated with
methicillin-resistant Staphylococcus aureus (MRSA).
MRSA commonly has occurred in health-care settings; however, recent investigations
of community-associated MRSA (CA-MRSA) have identified infection in various
settings, including correctional facilities, athletic teams, and others (CDC,
unpublished data, 2002). This report describes investigations of CA-MRSA in
Los Angeles County.
In September 2002, LACDHS investigated cases of MRSA infection in two
athletes on the same team who were hospitalized with MRSA within the same
week. No additional cases of MRSA have been identified. The source of MRSA
infection for these patients has not been determined.
On November 22, 2002, physicians from two large infectious disease clinical
practices notified LACDHS of MRSA skin infections among men who have sex with
men (MSM). LACDHS has increased surveillance in selected clinics serving MSM
and has begun a study of risk factors for infection among this population.
Currently, LACDHS is investigating an outbreak in the Los Angeles County
Jail, in which 928 inmates had MRSA wound infections diagnosed in 2002. Patients
were reported as having spider bites but subsequently were found to be infected
with MRSA. Review of medical charts of 39 of the 66 inmates hospitalized with
these infections indicated that all initially had skin infections, but 10
later had invasive disease, including bacteremia, endocarditis, or osteomyelitis.
The Los Angeles County Jail is the largest jail system in the United States;
165,000 persons are incarcerated in the jail each year. LACDHS issued recommendations
for the diagnosis and treatment of skin infections in the jail and is working
with the Los Angeles County Sheriff's Department to review policies and procedures
on laundry, showers, environmental cleaning, skin care, and control of person-to-person
In each of these outbreaks, antimicrobial susceptibility patterns from
MRSA isolates of these patients have been similar, including resistance to
fluoroquinolones. Molecular analysis by pulsed-field gel electrophoresis (PFGE)
of isolates performed at the Los Angeles County Public Health Laboratory has
identified a predominant strain common to all of these outbreaks. The PFGE
pattern of the predominant strain also is consistent with PFGE patterns that
CDC has identified in community outbreaks from other parts of the United States
(CDC, unpublished data, 2003). Selected MRSA isolates will be sent to CDC
to characterize their virulence factors and toxins.
LACDHS is advising health-care providers to be aware that MRSA is a
documented cause of community-associated skin and soft tissue infections.
Local treatment and incision and drainage remain first-line therapies for
soft tissue infections. Clinicians who suspect MRSA skin and soft tissue infections
should consider microbiologic culture of wounds and appropriate antimicrobial
Skin infections might be prevented by keeping cuts and abrasions clean
by washing with soap and water. Previous investigations of MRSA infection
clusters in community settings have identified MRSA transmission through sharing
common objects (e.g., athletic equipment, towels, benches, and personal items)
contaminated with MRSA (CDC, unpublished data, 2002). To prevent MRSA infections
from spreading in health-care settings, health-care providers should use standard
precautions and appropriate hand hygiene between treating patients, clean
surfaces of examination rooms with commercial disinfectant or diluted bleach
(1 tablespoon bleach in 1 quart water), and carefully dispose of dressings
and other materials that come into contact with pus, nasal discharge, blood,
The outbreaks described in this report reflect the importance of CA-MRSA
infections. In collaboration with state health departments, CDC is conducting
active, population-based surveillance for CA-MRSA in selected regions of the
United States to help characterize the incidence and risk factors for MRSA
in the community.
Participating physicians and microbiologists; Los Angeles County Jail;
Los Angeles County Dept of Health Svcs, Los Angeles County, California. Div
of Healthcare Quality Promotion, National Center for Infectious Diseases,
Public Health Dispatch: Outbreaks of Community-Associated Methicillin-Resistant. JAMA. 2003;289(11):1377. doi:10.1001/jama.289.11.1377