Healthcare Workers

Infectious Agents Risk Factors

What to know

  • Healthcare workers are routinely exposed to infectious organisms in their workplaces, including bacteria, fungi, viruses, and parasites.
  • Exposure to patients with specific conditions and bloodborne pathogens in the worksite can increase your risk of infection.
  • Follow infection control procedures to lower your risk of exposure.
Hand wearing surgical glove with a finger prick and blood.

Conditions that can increase risk


Influenza, or the flu, is a contagious respiratory illness caused by influenza viruses that infect the human respiratory system including the:

  • Nose
  • Throat
  • Lungs

Although some people experience a mild illness when infected with influenza, it can also be severe and lead to death. The best way to prevent influenza is by getting a flu vaccine each year.

Types of influenza include:

Methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is spread by contact with an infected wound or from contaminated hands. Following infection control practices such as using personal protective equipment (PPE), dedicated patient-care equipment, hand hygiene, and environmental cleaning and disinfection can reduce the risk of colonization or infection.


The bacteria that causes tuberculosis (TB) is spread through the air and can be released when an infected individual speaks, coughs, or sneezes. Protecting healthcare workers from tuberculosis requires a comprehensive TB infection control program. This program should be based on the hierarchy of controls. Measures to reduce transmission include administrative controls, engineering controls, and PPE such as respirators in special healthcare areas and specific procedures.

Coronavirus Disease 2019

Coronavirus Disease 2019 (COVID-19) is caused by the virus SARS-CoV-2. The virus is spread when infected people exhale droplets and very small particles containing the virus when they breathe, talk, or cough.

Some people infected with COVID-19 may not show signs of illness but can still spread the virus. The best way for healthcare workers to protect themselves is to be vaccinated. It is also important to have a comprehensive infection control program based on the hierarchy of controls.

Other factors that can increase risk

Bloodborne pathogens

Exposures to blood and other body fluids occur across a wide variety of occupations. Healthcare workers, emergency response and public safety personnel, and other workers can be exposed through:

  • Needlesticks and other sharps injuries
  • Mucous membrane
  • Non-intact skin

Pathogens of concern are the human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). Workers and employers can reduce risks of workplace transmission by taking precautionary measures that minimize exposures to blood and other body fluids.