Join ADAMember Log In




MRSA Research

Infection control journal reports MRSA research

Seattle – Research described as “the first study to characterize MRSA from dental clinic surfaces and dental students” is reported in the October 2011 issue of the American Journal of Infection Control.

Dental school responds to MRSA study

“It is not surprising that MRSA is found at our school or in any other clinical setting,” said Dr. Tim DeRouen, interim dean of the University of Washington School of Dentistry. “What is far more important for the health of our patients, students, faculty and staff is the level of precautions we take to prevent the transmission of MRSA or any other infectious agent.”
Researchers checked for the presence of methicillin-resistant Staphylococcus aureus at the UW School of Dentistry early in 2009. Their research was reported in the October 2011 issue of the American Journal of Infection Control.

Community-acquired methicillin-resistant Staphylococcus aureus infections “are on the rise,” says the research reported by the Association for Professionals in Infection Control and Epidemiology, Inc., and supported in part by a grant from the National Institute of Dental and Craniofacial Research.

“The current study was undertaken to determine whether MRSA could be isolated from frequently touched dental operator surfaces and clinic floors in different dental clinics within the (University of Washington) School of Dentistry. “In addition nasal cultures from dental students that used the clinics were taken, and all MRSA isolates were characterized.”

“This study is one of the first to look at MRSA in the dental setting, but it was a small study with just 61 students in one facility,” a CDC official said in WebMD commentary from CBS News. “We don’t believe this study necessarily represents a systematic problem in dental clinics across the country,” said Arjun Srinivasan, M.D., assistant director for CDC’s Healthcare-Associated Infection Prevention Program.

“We know a great deal about the infection control challenges related to MRSA in acute care hospital settings, but we know a lot less about this issue in non-acute care settings such as dental and dialysis centers and ambulatory surgical centers,” said Dr. Srinivasan.

Dr. Srinivasan said he agrees with researchers that more study is needed to develop a better understanding of the rate of MRSA colonization in non-hospital health care settings and how that impacts MRSA infection rates.

“These results are unlikely to be unique to the Pacific Northwest, and further studies are needed from more dental clinic surfaces, dental patients, dental personnel and students from diverse geographic locations,” says the report in the American Journal of Infection Control.

The dental school issued the following statement in response to an ADA News request for comment.

UW School of Dentistry responds to MRSA study in American Journal of Infection Control

A study published in the October 2011 issue of the American Journal of Infection Control describes the findings of researchers who checked for the presence of methicillin-resistant staphylococcus aureus (MRSA) at the UW School of Dentistry early in 2009.

Researchers took nasal swab samples from 61 dental students and also checked for MRSA on 95 surfaces in seven UWSOD clinics such as dental chairs, floors, sinks and counters. They found that 13 of the students (21 percent) and eight surfaces (8.4 percent) harbored MRSA.

One of the study’s authors, Dr. Jeremy Horst, cautioned that for several reasons, the study should not be cause for alarm by current or prospective patients at the dental school’s clinics. The study was not longitudinal, or done over an extended period, he noted; it presents only a snapshot of MRSA presence (colonization) at one particular time at the school. Another author of the study, Dr. Marilyn Roberts, added that the rates of colonization could change significantly if another sample were taken.

A separate study at the State University of New York dental school in Buffalo, N.Y., showed even higher rates of MRSA colonization – 31 percent – among students and instructors. It was presented at a 2009 meeting of the International Association of Dental Research.

Dr. Mark Drangsholt, Chair of the Department of Oral Medicine at the UW dental school, noted that even when MRSA is present in the nasal cavity, the risk of transmission and infection is low, especially with the use of gloves, masks and other universal precautions, which are followed in all UW School of Dentistry clinics. MRSA infections usually are not serious, although they can be life-threatening, especially among people whose immune systems are compromised.

Dr. Tim DeRouen, Interim Dean of the UW dental school, said: “It is not surprising that MRSA is found at our school or in any other clinical setting. What is far more important for the health of our patients, students, faculty and staff is the level of precautions we take to prevent the transmission of MRSA or any other infectious agent.”

The school has clear and comprehensive protocols and training for infection control; treatment of  patients with highly infectious diseases including MRSA, tuberculosis and SARS; and exposure to blood-borne pathogens, Dr. DeRouen noted. “We conduct treatment in our clinics as if every patient were HIV-positive,” he said. Among the school’s preventive measures:

  • Dental chairs are covered with disposable barriers for every patient, and disinfected after every patient’s treatment.
  • Floors, sinks and counters are cleaned and disinfected at the end of every day of clinical operation.
  • Clinical staff routinely conducts spore testing and uses chemical indicators in the School’s sterilization system.
  • Dental students, staff and faculty use barrier protection, such as disposable gloves and surgical masks.
  • Stringent sterilization procedures are followed for all dental instruments.

“We go to great lengths to ensure that our patients, students, faculty and staff have the lowest possible risk of infection,” Dr. DeRouen said.

Copies of the School of Dentistry’s infection control and related policies are available upon request.