top of page

An Introduction to Healthcare-Acquired Infections (HAIs)

While the general public may view the hospital as a place one goes to in order to get over an illness, healthcare professionals know better. Going to a healthcare setting such as a hospital, medical clinic, or laboratory is not without its health risks. In fact, there is a category of disease all to itself that is used to describe diseases that have been caught during a medical visit that the patient did not originally have upon arriving to the healthcare facility—nosocomial infections, also known as “health-care associated infections” or “hospital-acquired infections” (HAIs) (Jennifer Cheung n.d.). There are a variety of HAIs, so many that the Centers for Disease Control and Prevention (CDC), has created the following categories: central line-associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI), surgical site infections (SSI), and ventilator-associated pneumonia (VAP) (Centers for Disease Control and Prevention 2914).

HAIs vary in severity and transmissibility. HAIs are mostly transmitted through direct or indirect contact. HAIs can also spread through droplet transmission via the respiratory tract (Sikora and Zahra 2022). HAIs can come in the form of bacterial, viral, and fungal infections (WebMD Editorial Contibutors 2021). Bacterial infections, such as E. coli and Staphylococcus, also known as staph, are the most common type of HAI ( (WebMD Editorial Contibutors 2021), (WebMD Editorial Contributors 2021). Influenza is a common type of viral infection spread in healthcare settings. Fungal infections seen in healthcare settings include Candida, also known as thrush, and Aspergillus, a type of mold that impacts respiratory function ( (WebMD Editorial Contibutors 2021), (Frysh 2022)). COVID-19 is a known HAI, and a study published in January 2021 posits that 12-15% of COVID-19 cases are contracted in hospitals. However, it is important to note that this study did not consider healthcare workers who may have contracted COVID-19 while working, so the actual percentage will vary (Barranco, Vallega Bernucci Du Tremoul and Ventura 2021). Another HAI of infamy is Tuberculosis, a bacterial infection that causes 10 million people worldwide to fall ill each year (The World Health Organization n.d.).

The prevalence of HAIs in a country can be linked to the nation’s economic standing. As written by Barranco and Ventura, prevalence rates of HAIs in higher income countries are roughly 7.5%, whereas lower income countries can experience HAI prevalence rates from 5.7 to 19.2% (Barranco, Vallega Bernucci Du Tremoul and Ventura 2021). Elderly individuals are more likely to catch all categories of HAI, and they are more likely to experience cases of disease with higher severity (Barranco, Vallega Bernucci Du Tremoul and Ventura 2021). HAIs also place a financial burden on a country’s healthcare system and economy.

According to a paper published in 2009 by R. Douglas Scott II, the overall annual direct medical costs of HAIs to US hospitals ranged from $28.4 to $33.8 billion, and $35.7 to $45 billion depending on the Consumer Price Index (CPI) for all urban consumers or for inpatient hospital services (R. Douglas Scott 2009). Scott also posited that, compared to the costs of treating HAIs, the cost of preventive measures ranged from $5.7 to $6.8 billion in order to prevent 20% of preventable infections (CPI for urban consumers) and $25 to $31.5 billion to prevent 70% of preventable infections (CPI for inpatient hospital services) (R. Douglas Scott 2009).

In order to prevent HAIs, the following steps can be taken. First, healthcare facilities must have protocols in place to reduce the spread of diseases entering and exiting the healthcare setting (Jennifer Cheung n.d.). Frequent handwashing, the use of personal protection equipment (PPE), and regular disinfection of the workplace and medical tools are also encouraged, if not outright required (Jennifer Cheung n.d.). The CDC has also compiled an HAI Prevention Toolkit that instructs professionals on how to stop the spread of disease based on the healthcare setting, pathogen, environmental factors, and more (Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Healthcare Quality Promotion (DHQP) 2019). Finally, as suggested by R. Douglas Scott II, the allocation of extra funding toward HAIs, though costly, will greatly reduce the number of HAIs in the US specifically, though the logic can be applied worldwide (R. Douglas Scott 2009). HAIs are preventable, but the prevention effort must span across all levels of healthcare, from practitioners to administrative officials.


  • Barranco, Rosario, Luca Vallega Bernucci Du Tremoul, and Francesco Ventura. 2021. "Hospital-Acquired SARS-Cov-2 Infections in Patients: Inevitable Conditions or Medical Malpractice?" International Journal of Environmental Research and Public Health. Accessed October 19, 2022. doi:10.3390/ijerph18020489.

  • Centers for Disease Control and Prevention. 2914. Types of Healthcare-associated Infections. March 26. Accessed October 20, 2022.

  • Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Healthcare Quality Promotion (DHQP). 2019. Prevention Toolkits. June 28. Accessed October 20, 2022.

  • Frysh, Paul. 2022. What Is Aspergillosis? April 9. Accessed 10 19, 2022.

  • Jennifer Cheung, RN. n.d. Nosocomial Infection: What It Is, Causes, Prevention, and More. Accessed October 20, 2022.

  • Meier, JD, LLM, MPhil, Benjamin Mason, Patricia W Stone, PhD, MPH, and Kristine M Gebbie, RN, DrPH. 2008. "Public health law for the collection and reporting of health care-associated infections." American Journal of Infection Control 36 (8): 537-551. Accessed October 19, 2022. doi:10.1016/j.ajic.2008.01.015.

  • R. Douglas Scott, II. 2009. "The Direct Medical Costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention." Centers for Disease Control and Prevention. March. Accessed October 20, 2022.

  • Sikora, Anna, and Farah Zahra. 2022. Nosocomial Infections. Treasure Island (FL): StatPearls [Internet]. Accessed October 20, 2022.

  • The World Health Organization. n.d. Tuberculosis. Accessed 10 19, 2022.

  • WebMD Editorial Contibutors. 2021. What is a Nosocomial Infection? November 27. Accessed October 19, 2022.

  • WebMD Editorial Contributors. 2021. Staph Infection and Cellulitis. February 5. Accessed October 19, 2022.


Recent Posts

See All

OSHA Decedent Management Regulations

A part of healthcare that people often overlook is decedent care—what happens to a patient after they’ve passed away. When a patient passes away in a hospital or medical center, they are transferred t


bottom of page