What Are the Most Common Bloodborne Pathogens?
The three most common bloodborne pathogens of concern in the workplace are hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). These pathogens can be transmitted through infected human blood, and exposure can result in serious or chronic disease.
In this blog, we'll look at HBV, HCV, HIV, and other examples of bloodborne pathogens, the diseases they can cause, and how workers can reduce their risk. Employees whose jobs involve occupational exposure may also need appropriate bloodborne pathogens training courses.
The 3 Most Common Bloodborne Pathogens
When discussing occupational exposure, the three major bloodborne pathogens workers should know are HBV, HCV, and HIV. Each is a virus transmitted through infected blood, but they affect the body differently and present different considerations following exposure.
For a broader explanation of transmission, exposure routes, PPE, and prevention, read our guide to bloodborne pathogens .
| Pathogen | Disease | Primary Health Impact | Vaccine Available? | Key Exposure Considerations |
|---|---|---|---|---|
| Hepatitis B virus (HBV) | Hepatitis B | Primarily affects the liver and can cause acute or chronic infection | Yes | Can be transmitted through needlesticks and other exposure to infected blood or certain body fluids |
| Hepatitis C virus (HCV) | Hepatitis C | Primarily affects the liver and can cause chronic infection, cirrhosis, and liver cancer | No | Exposure commonly happens from percutaneous sharps injuries with infected blood to or certain body fluids with mucous membranes or nonintact skin. |
| Human immunodeficiency virus (HIV) | HIV infection | Attacks the immune system and can progress to AIDS without treatment | No | Occupational transmission is uncommon but can occur through needlesticks and other significant exposure to HIV-infected blood |
Hepatitis B (HBV)
Hepatitis B virus, or HBV, causes hepatitis B, a liver infection that can be either acute or chronic. Acute hepatitis B is a short-term infection, while chronic hepatitis B can lead to serious health problems such as cirrhosis and liver cancer.
HBV is an important occupational bloodborne pathogen because it can be transmitted when infected blood or certain body fluids enter another person's body. Needlesticks and other contaminated-sharps injuries are particularly common routes for exposure in the workplace.
The risk following an exposure depends on factors such as the source of the person's infection status and viral activity. Historically, studies of healthcare personnel injured by needles contaminated with highly infectious HBV-positive blood found substantial infection risks, demonstrating why HBV has long been a major focus of occupational bloodborne pathogen prevention.
Unlike HCV and HIV, hepatitis B can be prevented with vaccination. For workers with reasonably anticipated occupational exposure, OSHA's Bloodborne Pathogens Standard includes requirements related to making hepatitis B vaccination available.
Hepatitis C (HCV)
Hepatitis C virus, or HCV, causes hepatitis C, another infection that primarily affects the liver. Some people clear an acute infection without treatment, but hepatitis C can become chronic and eventually contribute to serious complications, including cirrhosis and liver cancer.
There is currently no vaccine for hepatitis C. However, modern antiviral medications can cure most people with HCV infection.
Occupational HCV transmission can occur following exposure to infected blood, particularly through needlesticks and other percutaneous injuries. According to the Centers for Disease Control and Prevention (CDC), the estimated risk of HCV transmission after percutaneous exposure to HCV-infected blood is approximately 0.2%.
Unlike HIV and HBV, CDC does not recommend routine post-exposure prophylaxis (PEP) for HCV. Instead, workers who experience a potential occupational exposure should promptly report it and follow appropriate testing and medical follow-up procedures.
Human Immunodeficiency Virus (HIV)
Human immunodeficiency virus (HIV) attacks cells that help the body fight infection, weakening the immune system. Without appropriate treatment, HIV infection can progress to acquired immunodeficiency syndrome (AIDS).
HIV can be transmitted when certain infectious body fluids from a person with HIV enter another person's bloodstream or come into contact with vulnerable tissues. In occupational settings, percutaneous injuries involving HIV-infected blood are an important potential exposure route. However, the likelihood of HIV transmission from an occupational exposure is relatively low. The 2025 U.S. Public Health Service guidelines estimate the average risk of HIV transmission following a percutaneous exposure to HIV-infected blood at approximately 0.23%. The estimated risk following mucous membrane exposure is lower.
Prompt evaluation is important after a potential HIV exposure because post-exposure prophylaxis (PEP) may be recommended. Workers should report possible exposures immediately and follow their employer's procedures for obtaining medical evaluation.
Other Types and Examples of Bloodborne Pathogens
HBV, HCV, and HIV receive much of the attention in occupational safety, but they aren't the only pathogens capable of transmission through blood.
Other infectious microorganisms may be bloodborne or capable of transmission through infected blood under certain circumstances.
Cytomegalovirus (CMV)
Cytomegalovirus (CMV) is a common virus in the herpesvirus family. It can be transmitted through several infectious body fluids, including blood, urine, saliva, tears, semen, and breast milk.
Most healthy people who acquire CMV have no symptoms or experience only mild illness. However, CMV can cause serious complications in certain populations, including immunocompromised individuals and infants infected before birth.
Although occupational CMV transmission is possible, the CDC notes that it appears to be very rare in healthcare settings. Healthcare personnel have not been demonstrated to be at greater risk of acquiring CMV than the general population.
Other Bloodborne Pathogen Examples
Additional types of bloodborne pathogens or infections capable of bloodborne transmission include:
- Syphilis : Primarily transmitted through sexual contact, although the bacteria that cause syphilis can be transmitted through blood under certain circumstances.
- West Nile virus (WNV) : Primarily spread through infected mosquitoes, but transmission through blood transfusion and organ transplantation has occurred.
- Malaria : Usually transmitted through infected mosquitoes but can also be transmitted through infected blood, including through transfusion or contaminated needles.
- Babesiosis : Usually transmitted through tick bites but can also spread through transfusion of contaminated blood.
- Brucellosis : Primarily associated with infected animals or animal products, but rare bloodborne transmission can occur.
- Viral hemorrhagic fevers : Certain viruses, including Ebola and Marburg viruses, can spread through infected blood and other body fluids.
These examples demonstrate an important distinction: a pathogen doesn't necessarily need to be primarily bloodborne for transmission through blood to be possible.
What Diseases Can Be Contracted From Bloodborne Pathogens?
Bloodborne pathogens can cause diseases affecting several different systems in the body. The specific health effects depend on the pathogen involved.
| Bloodborne Pathogen | Associated Disease or Infection | Potential Health Effects |
|---|---|---|
| HBV | Hepatitis B | Acute or chronic liver infection, cirrhosis, liver cancer |
| HCV | Hepatitis C | Acute or chronic liver infection, cirrhosis, liver cancer |
| HIV | HIV infection/AIDS | Progressive damage to the immune system |
| CMV | Cytomegalovirus infection | Usually mild or asymptomatic in healthy adults but potentially serious for certain high-risk populations |
| Treponema pallidum | Syphilis | Multistage infection that can affect multiple organ systems if untreated |
| West Nile virus | West Nile virus disease | Usually asymptomatic or mild, but potentially serious neurologic disease |
| Plasmodium parasites | Malaria | Fever and systemic illness, with potentially severe complications including organ failure, seizures, and comas. |
| Babesia parasites | Babesiosis | Infection of red blood cells ranging from asymptomatic to severe illness |
The presence of a pathogen in blood doesn't mean every contact will result in infection. Transmission risk varies based on the pathogen, type of exposure, amount of infectious material involved, and other circumstances.
How Can Workers Reduce Their Risk From Bloodborne Pathogens?
Bloodborne pathogen exposure is preventable in many workplace situations. Workers should follow the procedures established for their specific jobs and understand which tasks may expose them to blood or OPIM (Other Potentially Infectious Materials).
Important prevention measures include:
- Treating blood and applicable OPIM as potentially infectious according to Universal Precautions
- Using appropriate personal protective equipment (PPE), such as gloves, gowns, masks, and eye protection, based on the anticipated exposure
- Using engineering controls, including appropriate sharps disposal containers and safer medical devices where applicable
- Following safe work practices when using and disposing of needles and other sharps
- Practicing appropriate hand hygiene
- Following established procedures for handling contaminated equipment, laundry, and regulated waste
- Promptly reporting exposure incidents and obtaining appropriate medical evaluation
Workers responsible for contaminated surfaces or materials should also follow established procedures for bloodborne pathogen cleanup and disposal .
Research also illustrates why prevention practices matter. A study by Dr. Michelle Kermode and colleagues examined occupational blood exposure among healthcare workers in rural North India and found frequent percutaneous injuries within the population studied. While the findings shouldn't be generalized to every workplace or today's U.S. workforce, the study highlights the relationship between occupational blood exposure and adherence to Universal Precautions.
Understand Bloodborne Pathogen Safety and Training Requirements
Knowing examples of bloodborne pathogens is only one part of staying safe around blood and OPIM. Workers also need to understand how exposure can occur, which controls their workplace uses, what PPE is appropriate, and what steps to take if an exposure incident happens.
In the United States, OSHA's Bloodborne Pathogens Standard, 29 CFR 1910.1030 , applies to employees with reasonably anticipated occupational exposure to human blood or OPIM. Covered employers must implement measures designed to eliminate or minimize that exposure, including an Exposure Control Plan, engineering and work practice controls, appropriate PPE, hepatitis B vaccination provisions, post-exposure evaluation and follow-up, and employee training.
Employees with occupational exposure must receive bloodborne pathogen training when initially assigned to tasks where occupational exposure may occur and at least annually thereafter. Additional training may also be required when changes to tasks or procedures affect occupational exposure.
United States workers can learn more about U.S. employer obligations and bloodborne pathogens training requirements here.
However, requirements outside the United States differ. Workers and employers in Canada can explore our Canadian BBP training and should follow the occupational health and safety requirements applicable to their province, territory, and workplace.
Whether you work in healthcare, public safety, sanitation, laboratory services, or another field where occupational exposure may occur, understanding bloodborne pathogens can help you recognize hazards and follow the appropriate precautions. Explore 360training's online bloodborne pathogen courses to learn more about workplace exposure, prevention, and safety practices.
