Classifying Worker Exposure to Bloodborne Pathogens
Classifying Worker Exposure to Bloodborne Pathogens
As with any type of personal protective equipment (PPE), the key to proper selection and use of gowns and coveralls is to understand the hazards and the risk of exposure. The Centers for Disease Control and Prevention (CDC) has categorized three primary routes of transmission:
- (i) contact (direct and indirect),
- (ii) respiratory droplets, and
- (iii) airborne droplet nuclei [Siegel 2007].
- Contact transmission is generally the most common and direct contact occurs when microorganisms transfer directly from one person to another.
- Airborne transmission occurs by dissemination of either airborne droplet nuclei or small particles in the respirable size range containing infectious agents.
- Droplet transmission refers to respiratory droplets generated through coughing, sneezing, or talking. By using appropriate protective clothing, it is possible to create a barrier to eliminate or reduce contact and droplet exposure, and therefore prevent the transfer of microorganisms between patients and healthcare workers. This document provides information about protective clothing standard test methods and classification standards when the transmission of the microorganisms is through direct contact with blood or body fluids. Direct contact can occur through broken skin or mucous membranes located areas such as the eyes, nose, or mouth. In addition to blood, other body fluids can include (but are not limited to) urine, saliva, sweat, feces, vomit, breast milk, and semen.
Employers should conduct a thorough risk assessment first to identify potential exposures to blood and body fluids. The risk of exposure sometimes depends on the stage of the disease and severity of symptoms. For example, for Ebola virus disease, severe symptoms are strongly associated with high levels of virus production. In addition, close contact with the patient and invasive medical care can increase opportunities for transmission. This should be considered during the risk assessment, such as in the case of Ebola virus disease, as Ebola patients can release large volumes (as much as 8 liters/day) of body fluids (vomit, diarrhea) [Kreuels 2014]. A complete assessment of the risks is outside the scope of this document, but resources are available. For example, the Association for the Advancement of Medical Instrumentation (AAMI) published a guidance document on selection and use of protective apparel in healthcare facilities, Technical Information Report (TIR) 11pdf iconexternal icon [AAMI 2005]. Some of the factors important to assessing the risk of exposure in health facilities include source, modes of transmission, pressures and types of contact, and duration and type of tasks.
