Piazza M; Borgia G; Picciotto L; Nappa S; Cicciarello S; Orlando R Institute of Infectious Diseases, University of Naples Federico II, Italy. J Med Virol 45: 40-2 (1995)

Abstract

The mean prevalence of anti-hepatitis C virus (HCV) in Italy is 0.87%. It reaches 2% in Campania, Southern Italy. Approximately 50% of community acquired non-A, non-B (NANB) hepatitis cannot be associated with known parenteral exposure. A recent Italian study has shown that the only demonstrable risk factor in 9% of acute C/NANB hepatitis is dental treatment. There are no data on direct contamination by HCV of dental surgeries. Possible environmental contamination by HCV-RNA was investigated in dental surgeries after treatment of anti-HCV and HCV-RNA positive patients. Thirty-five anti-HCV and HCV-RNA positive patients with chronic hepatitis underwent dental treatment and were enrolled in this study. Eight had chronic persistent hepatitis (CPH), 23 chronic active hepatitis (CAH), and 4 cirrhosis. A total of 328 samples collected from instruments and surfaces were tested after dental treatment of 35 anti-HCV positive patients. The presence of HCV-RNA was determined by polymerase chain reaction (PCR) to evaluate contamination of instruments and surfaces in dental surgeries. Twenty (6.1%) out of 328 collected samples were positive for HCV-RNA. The positive samples were from work benches (two), air turbine handpieces (one), holders (four), suction units (one), forceps (four), dental mirrors (two), and burs (six). Our data indicate that there is extensive contamination by HCV of dental surgeries after treatment of anti-HCV patients and that if sterilisation and disinfection are inadequate there is the possible risk of transmission to susceptible individuals

     A survey of 434 oral surgeons was conducted to examine risk factors for hepatitis B virus (HBV) infection. Overall, 112 (26%) of the participants demonstrated serologic evidence of past or current infection with HBV. Seropositivity was significantly associated with age, number of years in practice, and year of graduation from dental school but not with other variables examined, such as the number of patients seen annually or the number of patients seen who were at high risk of HBV infection. The strong correlation between years in practice and seropositivity was unaffected by reported use of gloves, face masks, or eye shields. The use of gloves and other protective devices does not appear to offer substantial protection against HBV exposure in oral surgeons, and all oral surgeons should receive HBV vaccine. PMID: 3357229, UI: 88188297   

Most healthcare workers who have transmitted to patients have several  factors in common (Exs. 6-476; 6-471): 

(1) The dentists and surgeons were chronic HBV carriers, had high titers  of virus in their blood (HBeAg positive), and were unaware that they were infected. 

(2) Transmission occurred most frequently during the most traumatic procedures. 

(3) The dental personnel who transmitted did not routinely wear gloves. However, some infected HCWs continued to transmit HBV to patients in spite of the use of gloves and additional precautions. 

(4) The dentists and surgeons often had a personal medical problem (such as exudative dermatitis on the hands), or used techniques that made transmission more likely. Several of the gynecologists used their index fingers to feel for the tip of the suture needle when they were performing deep abdominal surgery. http://www.osha-slc.gov/Preamble/Blood_data/BLOOD4.html   

Am Dent Assoc 1986 Sep;113(3):390-6 Schiff ER, de Medina MD, Kline SN, Johnson GR, Chan YK, Shorey J, Calhoun N, Irish EF 

     Personnel in the VA dental facilities were screened for the detection of viral hepatitis and identification of factors implicating infectivity. A total of 963 personnel from 126 dental facilities throughout the United States voluntarily participated in the study. The rate of seroconversion for any hepatitis B markers was approximately 1% per year. Serial positive tests for antibody to hepatitis B core antigen or antibody to hepatitis B surface antigen (or both) were present in 16.2% of dentists and 13.0% of dental auxiliary personnel. Oral and maxillofacial surgeons composed the highest prevalence occupation (24.0%), and clinical personnel composed the lowest prevalence occupation (8.9%). There was a significant association between years in dental environment and serological positivity for viral B infection. The dentists and dental auxiliary personnel had significant linear trends of increasing serological positivity with years in the dental environment. Although a majority of personnel reported wearing gloves while treating high-risk patients or performing invasive procedures, inadequate prophylactic measures were exercised for most patients undergoing a variety of less invasive procedures. The results of the study show the need for an active immunization program against type B viral infection for dental and dental auxiliary personnel, preferably before the initial exposure to the professional environment. PMID: 3531282, UI: 87009463        

PHILADELPHIA INQUIRER AIDS VIRUS SURVIVES DENTAL-TOOL WASH HEAT STERILIZATION IS URGED. A STUDY FOUND WASHINGTHE TOOLS WITH DISINFECTANT DIDN'T DO THE JOB.
Published on 11/21/1992,