MRSA in the Dental Office
MRSA in the Dental Office
Potential sources of infection in the dental healthcare setting include blood-borne pathogens (cytomegalovirus, hepatitis B virus, hepatitis C virus, HIV), herpes simplex, Mycobacterium tuberculosis, staphylococci, streptococci, and other viruses and bacteria that colonize or infect the oral cavity and respiratory tract. Some of these bacteria are drug resistant, with the most well known of these being MRSA. Now endemic in hospitals, MRSA is resistant to all currently available beta-lactam antimicrobial agents. MRSA emerged more than 40 years ago as a source of infections in hospitals and long-term care facilities, hence the label "healthcare-associated MRSA" (HA-MRSA), a cause of surgical site and bloodstream infections in hospitalized patients. Recently, microbiologically distinct strains of MRSA, known as community-associated MRSA (CA-MRSA) have arisen, which cause primarily skin and soft tissue infections among previously healthy persons living in the community.
Colonization refers to the presence of microorganisms in or on a host with growth and multiplication but without tissue invasion or damage. In the case of MRSA, the body site most commonly colonized is the anterior nares, but colonization of the oral cavity with MRSA has also been described. MRSA has also been found on dentures.
Other body sites that may be colonized with MRSA include open wounds, the respiratory tract, the perineum, the upper extremities, the umbilicus (in infants), the urinary tract, and the axilla. Colonized patients are also known as asymptomatic carriers.
Infection is the entry and multiplication of microorganisms in the tissues of the host leading to local or systemic signs and symptoms of infection. Most CA-MRSA infections are found in skin abscesses, boils, or pustules (Figure 1).
Figure 1. MRSA skin infection. From CDC/Bruno Coignard, MD, Jeff Hageman, MHS, 2005.
Individuals who are colonized with MRSA, just as those who are infected with MRSA, can serve as reservoirs for MRSA and transmit the bacteria to others.
The prevalence of MRSA is increasing in the United States. In hospitals, the overall MRSA prevalence rate is 46.3 per 1000 inpatients (34 infections and 12 colonizations per 1000). The latest figures indicate that the prevalence of colonization with S aureus is 28.6% of the general population, whereas the prevalence of colonization with MRSA is 1.5%.
Although anyone can be colonized or infected with MRSA, epidemiologic evidence indicates that there are a few high-risk groups, including:
Most patients with simple MRSA skin or soft tissue infections are treated with incision and drainage, often without antibiotics. Patients with invasive MRSA disease (pneumonia, sepsis/bacteremia, severe bone/joint infection) must be treated in the acute-care setting because these conditions can be fatal. Neither the American Dental Association nor the CDC makes a recommendation about avoiding dental treatment for patients with invasive MRSA disease.
An Overview of Potential Pathogens
Potential sources of infection in the dental healthcare setting include blood-borne pathogens (cytomegalovirus, hepatitis B virus, hepatitis C virus, HIV), herpes simplex, Mycobacterium tuberculosis, staphylococci, streptococci, and other viruses and bacteria that colonize or infect the oral cavity and respiratory tract. Some of these bacteria are drug resistant, with the most well known of these being MRSA. Now endemic in hospitals, MRSA is resistant to all currently available beta-lactam antimicrobial agents. MRSA emerged more than 40 years ago as a source of infections in hospitals and long-term care facilities, hence the label "healthcare-associated MRSA" (HA-MRSA), a cause of surgical site and bloodstream infections in hospitalized patients. Recently, microbiologically distinct strains of MRSA, known as community-associated MRSA (CA-MRSA) have arisen, which cause primarily skin and soft tissue infections among previously healthy persons living in the community.
Colonization refers to the presence of microorganisms in or on a host with growth and multiplication but without tissue invasion or damage. In the case of MRSA, the body site most commonly colonized is the anterior nares, but colonization of the oral cavity with MRSA has also been described. MRSA has also been found on dentures.
Other body sites that may be colonized with MRSA include open wounds, the respiratory tract, the perineum, the upper extremities, the umbilicus (in infants), the urinary tract, and the axilla. Colonized patients are also known as asymptomatic carriers.
Infection is the entry and multiplication of microorganisms in the tissues of the host leading to local or systemic signs and symptoms of infection. Most CA-MRSA infections are found in skin abscesses, boils, or pustules (Figure 1).
Figure 1. MRSA skin infection. From CDC/Bruno Coignard, MD, Jeff Hageman, MHS, 2005.
Individuals who are colonized with MRSA, just as those who are infected with MRSA, can serve as reservoirs for MRSA and transmit the bacteria to others.
The prevalence of MRSA is increasing in the United States. In hospitals, the overall MRSA prevalence rate is 46.3 per 1000 inpatients (34 infections and 12 colonizations per 1000). The latest figures indicate that the prevalence of colonization with S aureus is 28.6% of the general population, whereas the prevalence of colonization with MRSA is 1.5%.
High-Risk Patients
Although anyone can be colonized or infected with MRSA, epidemiologic evidence indicates that there are a few high-risk groups, including:
Persons with frequent contact with the healthcare system, especially those on dialysis;
Athletes;
Children who go to daycare;
Inmates of correctional facilities; and
Elderly or other patients who reside in long-term care facilities.
Most patients with simple MRSA skin or soft tissue infections are treated with incision and drainage, often without antibiotics. Patients with invasive MRSA disease (pneumonia, sepsis/bacteremia, severe bone/joint infection) must be treated in the acute-care setting because these conditions can be fatal. Neither the American Dental Association nor the CDC makes a recommendation about avoiding dental treatment for patients with invasive MRSA disease.