Risk factors affecting occupational exposure to blood and body fluids among dental students : a cross-sectional study in a Brazilian Federal University

Abstract

Introduction: Dental students are often exposed to bloodborne pathogens during dental training. Several factors are involved in increased risk of human deficiency, hepatitis B and hepatitis C virus (HIV, HBV, and HCV) infection. However, there are few studies that address the risks and forms of prevention among dental students in Brazil. Methods: A cross-sectional study of occupational exposure to blood or body fluids among dental students of Universidade Federal do Rio Grande do Sul, Brazil, was performed. These students were referred to the Occupational Medicine Department of Hospital de Clínicas de Porto Alegre from January 2007 to April 2015. Analyzed data included type of exposure (needlestick injury, mucosal exposure, and exposure to non-intact skin); source patient status for HBV, HIV and HCV infection, accident during dental training, procedure performed, biological material involved, type of accident, and hepatitis B vaccination and serological protection status. The objective was to know the incidence rate and others characteristics of accidents in order to prevent them. Results: There were 312 accidents during the study period of 8 years and 4 months. Incidence rate was 87,42 exposures per 1000 students year. Source patient was known in 297 of the cases (95.2%), of which 3 were HBsAg reagent, 12 were HIV reagent, and 17 were HCV reagent. The majority of accidents occurred during procedure, but nearly as high as 40% occurred after procedure, of which 63% occurred during instrument cleaning, disinfecting or sterilizing. Most involved sharp instruments were anesthetic syringe needle and curette. Only 48% of dental students knew their anti- HBs was > 10 mIU/mL. Conclusions: Dental students should be tested for hepatitis B immune status at the beginning of training, and vaccination should be available to all dental students before they start clinical practice. Work practice controls on sharp devices should be addressed at the beginning and strengthened during dental training. Dental training institutions should review instrumental cleaning process to minimize handling of loose contaminated instruments.