A bloodborne pathogen (BBP) is a microorganism found in human blood that can cause disease. These pathogens, which include viruses and bacteria, are transmitted when infected blood or other specific body fluids enter another person’s body. Managing these infectious agents is primarily addressed through occupational safety standards. Understanding the risk of BBPs is important for anyone who may encounter human blood.
Key Pathogens Transmitted by Blood
The most commonly known bloodborne pathogens include three viruses: Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Human Immunodeficiency Virus (HIV).
HBV and HCV are hepatotropic viruses that target the liver, causing inflammation known as hepatitis. Chronic infection can lead to severe complications such as cirrhosis, liver failure, and liver cancer.
HIV targets the body’s immune system by attacking specific immune cells. This makes the infected individual vulnerable to opportunistic infections and certain types of cancers. If left untreated, the infection progresses to Acquired Immunodeficiency Syndrome (AIDS), the most advanced stage of the disease.
HBV and HCV are significantly more infectious than HIV in an exposure setting. Hepatitis B is highly stable and can remain viable on surfaces for up to a week. The risk of transmission following a percutaneous exposure to HBV-infected blood is considerably higher than the risk associated with HIV exposure. While there is no vaccine for Hepatitis C, highly effective antiviral treatments can cure the majority of chronic HCV infections.
How Exposure and Transmission Occur
BBPs are primarily transmitted when contaminated blood or other potentially infectious materials (OPIM) enter a person’s bloodstream or mucous membranes.
The most concerning route, especially in occupational settings, is a percutaneous injury. This involves the skin being punctured or cut by a contaminated sharp object (e.g., needle, scalpel), allowing the pathogen to bypass the body’s protective layer.
The second major route involves contact with the mucous membranes (the moist linings of the eyes, nose, or mouth). A splash or spray of infected fluid onto these tissues allows the pathogen to enter the body.
Contact with non-intact skin also represents a viable pathway for transmission. Non-intact skin includes any break in the surface, such as cuts, abrasions, dermatitis, or sunburn. Indirect transmission, while less common, occurs when a person touches a contaminated surface and then transfers the infectious material to an entry route.
Implementing Protection and Safety Standards
Protection against bloodborne pathogens is built upon a fundamental concept known as Universal Precautions. This approach dictates that all human blood and certain body fluids must be treated as if they are known to be infectious for HBV, HCV, HIV, and other bloodborne pathogens. Universal Precautions eliminates the need to differentiate between known or suspected infectious sources, creating a consistent safety standard for all exposure possibilities.
Workplace safety is governed by the Occupational Safety and Health Administration (OSHA) Bloodborne Pathogens standard (29 CFR 1910.1030). This standard outlines a hierarchy of controls that employers must implement to eliminate or minimize employee exposure.
The first line of defense consists of engineering controls, which are physical changes to the work environment or devices themselves. Examples include the use of sharps disposal containers, which are puncture-resistant and closable. They also include the adoption of safer medical devices like needleless systems or self-sheathing needles.
The next level of defense involves work practice controls, which are changes in the manner in which tasks are performed to reduce the likelihood of exposure. These controls include actions like proper handling and disposal of contaminated sharps. They also prohibit the recapping of needles using a two-handed technique.
Finally, Personal Protective Equipment (PPE) provides a barrier between the employee and the infectious material. This includes items such as gloves, gowns, face shields, and eye protection. PPE must be provided and maintained by the employer at no cost to the worker.
A significant preventative measure available is the Hepatitis B vaccination, which the OSHA standard mandates must be offered to all employees at risk of occupational exposure. This vaccine provides effective protection against HBV infection. Timely post-exposure evaluation and follow-up are also required for any employee who experiences an exposure incident.