Transmission of Blood-borne Pathogens in US Dental Health Care Settings
The transmission of blood-borne pathogens (BBP) in a dental setting is exceedingly rare. The low rate of transmission can be attributed to the hepatitis B virus vaccine and the implementation of universal precautions in the ’80s. Additional guidance provided by the CDC in 1996 expanded the elements of universal precautions and changed the term to standard precautions. In a literature review published September 2016 in the Journal of the American Dental Association, the authors reviewed three reports describing the transmission of hepatitis B virus (HBV) and hepatitis C virus (HCV) in a dental setting.1
Infection prevention guidelines are in place to prevent transmission from patient to dental health care personnel (DHCP), from DHCP to patent, and from patient to patient. In the first case, the reported transmission occurred in 2002 in an oral surgeon’s practice. The published report noted that the suspected mode of transmission was speculated to be “a lapse in cleaning environmental surfaces” post-operative, resulting in cross-contamination. This incident resulted in a patient to patient transmission of HBV. This incident required 27 people to be notified and screened for possible infection.
The second case reported involved five confirmed infections with HBV. The setting was a free dental clinic conducted in a school gymnasium. The number of people notified and screened exceeded 1,500. The mode of transmission was identified as “multiple procedural and infection prevention and control breaches were identified during the retrospective investigation.” Of the five confirmed cases, 3 were patients, and 2 were DHCP. The DHCP was not vaccinated for HBV, nor had they received infection control training, both contributing factors to the transmission of HBV.
The third and final case reported was from an oral surgeon’s practice; again, this case was a patient to patient transmission. The mode of transmission was cited as “multiple lapses in infection prevention and control were found, most notably related to administration of intravenous sedation medications by unsupervised, unlicensed and untrained dental assistants.” The most likely source was caused by DHCP reentering medication vials with a syringe that was contaminated. This risk can be eliminated by using single-use vials. This exposure required 5,810 people to be notified and screened for possible infection with HCV.
HBV and HCV can persist on surfaces for extended periods of time. Evidence shows that HBV can survive in dried blood at room temperature on environmental surfaces for at least 1 week. While HCV can survive in the environment on dry surfaces for up to 6 weeks. DHCP should be trained and have access to easily understandable guidelines. Additionally, vaccination can greatly reduce HBV transmission. Since 1987, 5 years after the HBV vaccine became commercially available, there have been no transmissions of HBV in dental settings that involved an infected dentist. This is quite likely to be directly related to the 74% increase in the vaccination rate among DHCP between 1983 and 1992.
The authors conclude by stating, “The results of our review of reported transmissions of BBPs since 2003 indicate that the transmission of BBPs in US dental settings is infrequent. This finding emphasizes the overall importance adhering to dental infection prevention recommendations, including standard precautions, to prevent BBP transmission and the dramatic effects of vaccination against HBV.”
Does your practice have annual infection control courses? Is infection control course required for your state licensure? Have you been vaccinated for HBV? Have you witnessed lapses in infection control? If so, how did you handle the incident?
- Cleveland JL, Gray SK, Harte JA, Robison VA, Moorman AC, Gooch BF. Transmission of blood-borne pathogens in US dental health care settings: 2016 update. J Am Dent Assoc. 2016;147(9):729-738. doi:10.1016/j.adaj.2016.03.020