Biological Hazards

Biological hazards are disease producing agents (pathogens) that can be transmitted to individuals through various routes of exposure (modes of transmission). Exposure to these hazards may result in acute or chronic health conditions.

Examples of Pathogens and Common Modes of Transmission

Hepatitis B Virus (HBV)
Hepatitis C Virus (HCV)
Human Immunodeficiency Virus (HIV)

Hepatitis A Virus (HAV)
Hepatitis E Virus (HEV)

Herpes Simplex Viruses (HSV)
Human Papilloma Virus (HPV)
Cytomegalovirus (CMV)
Vancomycin Resistant Enterococcus (VRE)
Methicillin Resistant Staphylococcus Aureus (MRSA)
Clostridium difficile (C. difficile)

Mycobacterium Tuberculosis

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)
Herpes Zoster Virus (HZV)
Influenza virus (Flu)
Measles (Rubeola virus)

The modes of transmission depend on where the microbe resides (the source/reservoir) and how it exits the source/reservoir (Association for Professionals in Infection Control, 2016; Centers for Disease Control and Prevention, 2006/2012). Components to the mode of transmission are called the chain of infection.

Page last reviewed: June 10, 2022

Content source: National Institute for Occupational Safety and Health

Biological Hazards

Follow NIOSH

NIOSH Homepage