A bloodborne pathogen (BBP) is a microorganism, such as a virus or bacterium, that is present in human blood and other potentially infectious materials (OPIM) and can cause disease in humans. These pathogenic agents pose a significant health risk because they can be transmitted from one person to another through contact with infected body fluids. Understanding how these microorganisms are carried and spread is a fundamental step in protecting individuals in environments where exposure is a possibility, such as healthcare settings or through certain occupational duties.
Major Pathogenic Agents
The most medically concerning and widely studied bloodborne pathogens are the Hepatitis B Virus (HBV), the Hepatitis C Virus (HCV), and the Human Immunodeficiency Virus (HIV). These three viruses are responsible for the majority of severe bloodborne infections globally.
HBV is a partially double-stranded DNA virus that attacks the liver, leading to inflammation called hepatitis. This infection can be acute, resulting in a flu-like illness, or can persist as a chronic infection, potentially causing liver cirrhosis or hepatocellular carcinoma, which is a type of liver cancer. HBV is reported to be up to 100 times more infectious than HIV and can survive on surfaces for up to one week.
HCV, a single-stranded RNA virus, also primarily targets the liver. Chronic infection occurs in approximately 70% of those initially infected, frequently progressing silently over many years to cause severe liver damage, including cirrhosis and liver failure. There is currently no effective vaccine to prevent HCV infection, making prevention of exposure particularly important.
The Human Immunodeficiency Virus (HIV) is a retrovirus that infects and destroys specific white blood cells called CD4 T cells, which are a central component of the immune system. This progressive destruction of immune cells weakens the body’s ability to fight off infections and diseases, eventually leading to Acquired Immunodeficiency Syndrome (AIDS).
Understanding Transmission Routes
Bloodborne pathogens require a specific route of entry to establish an infection in a new host, and this typically involves contact between infected blood or OPIM and a person’s bloodstream or mucous membranes.
The primary mechanism for transmission in occupational and accidental settings is percutaneous injury, which is the penetration of the skin by a contaminated sharp object. This includes accidental needlesticks, cuts from broken glass, or injury from other sharp medical instruments that have been soiled with infectious materials.
Transmission can also occur when infected fluids contact the delicate tissues of the mucous membranes, specifically the eyes, nose, or mouth. A splash or spray of contaminated blood or OPIM into the eyes, for instance, provides a direct pathway for the pathogens to enter the body. The mucous membranes are highly vascularized, making them an easy entry point for these viral agents.
A third route involves contact with non-intact skin, which refers to skin that is compromised by cuts, abrasions, dermatitis, acne, or even severe sunburn. While intact skin forms an effective barrier, any break in the skin allows the pathogen to bypass the body’s natural defenses and enter the underlying tissue or bloodstream. Other potentially infectious materials (OPIM) capable of transmitting BBP include semen, vaginal secretions, cerebrospinal fluid, amniotic fluid, and any body fluid that is visibly contaminated with blood.
Essential Exposure Prevention Methods
The foundational strategy for preventing exposure to bloodborne pathogens is known as Universal Precautions, which mandates that all human blood and OPIM be treated as if they are known to be infectious. This approach eliminates the need to assess the infection status of the source and ensures that protective measures are always consistently applied. By treating every exposure risk with the same high level of caution, the likelihood of accidental transmission is significantly reduced.
Personal Protective Equipment (PPE) provides a physical barrier and is a highly effective element of this preventative strategy. The specific PPE used depends on the anticipated exposure, but commonly includes disposable gloves, protective eyewear such as goggles or face shields, and fluid-resistant gowns or aprons. Gloves, for example, must be worn whenever contact with blood or OPIM is expected, and they should be immediately replaced if torn or punctured.
Proper management of contaminated sharps and surfaces is also a requirement for controlling exposure risks. Sharps, which are objects capable of penetrating the skin, must be immediately disposed of in designated, puncture-proof, and clearly labeled sharps containers after use. For spills of blood or OPIM on surfaces, the area should first be covered with an absorbent material, then thoroughly treated with an approved disinfectant, such as a freshly prepared 1:10 solution of household bleach, and allowed sufficient contact time to kill the pathogens. All cleanup materials, including used PPE, must be carefully contained and disposed of as biohazardous waste.