Hospital Acquired Infections (HAI)

Each year approximately 1 in 25 patients who are treated in a hospital are diagnosed with at least one infection related to their care in that hospital.  Even more infections occur in health care settings other than hospitals and are not included in this statistic.  Many of these Hospital Acquired Infections (HAIs) are caused by the most serious, antibiotic-resistant bacteria and in severe cases, may lead to sepsis or even death. According to The Joint Commission, 1 in 4 patients who acquire their infection in a healthcare facility will die.

In 2016, the Center for Disease Control (CDC) estimated the total number of HAIs at 1.7 million infections annually resulting in over 99,000 deaths.  From a patient perspective, acquiring a HAI increased hospital stays by an average of 17.6 days and cost our health care system $35B that year. Note that the number of HAIs has continued to steadily rise in the subsequent years.

CMS, the Centers for Medicare & Medicaid Services, has created Legionella requirements that facilities must develop and adhere to policies and procedures that inhibit microbial growth in building water systems that reduce the risk of growth and spread of Legionella and other opportunistic pathogens in water.

Also see The Joint Commission Water Management Standard.

HAIs are caused by pathogens, namely viral, fungal and bacterial pathogens.  The types of HAIS acquired fall into one of four categories:

  1. Blood Stream Infection (BSI)
  2. Urinary Tract Infection (UTI)
  3. Surgical Site Infection (SSI)
  4. Pneumonia (Ventilator- Associated Pneumonia or VAP)

Becker’s Clinical Leadership and Infection Control published that the most common infections acquired in health care settings were pneumonia (21.8%) and surgical site infections (21.8%).

Try our free, online CDC Legionella risk assessment and learn about our Legionella risk assessment and Legionella testing.

When looking at an academic study by Margaret M. Williams regarding HAIs and water systems, she expressed that the total burden of HAIs attributed to water was truly unknown. Most estimates claim waterborne pathogens cause 33% of HAIs. Waterborne pathogens could be transmitted by direct contact (bathing, hydrotherapy), ingesting of water (drinking water), indirect contact (improperly sterilized medical devices), inhalation of aerosols generated by a water source (ventilators) or aspiration of contaminated water.  The pathogens responsible for the HAIs tend to multiply fastest when water temperatures are 77-108 deg F while optimum growth is at 95 deg F, the temperature most frequent in manmade systems.  Under favorable environment conditions, waterborne pathogens could multiply and remain viable for long periods of time, ultimately responsible for infections in susceptible patient populations.

The waterborne pathogens that have been found responsible for HAIs include Pseudomonas (infection), Stenotrophomonas (causing respiratory infection), Acinetobacter (infection), Sphingomonas (aerobic), Burkholderia (aerobic), Achromobacter (aerobic) and Legionella (causing Legionnaires’ Disease or the milder, flu-like Pontiac Fever).  An interesting note is that each of these seven bacteria are gram-negative.  Research has shown that when exposed to various materials, copper and copper alloys proved to be anti-bacterial.  Since It has been proven that copper can be toxic to gram-negative bacteria, the installation of copper piping in hospital water distribution systems may decrease the likelihood of bacteria formation and growth.  However, the inside of copper lines usually oxidizes fairly quickly and this layer offers no anti-bacterial benefit. With the complexity of health care facilities and their water systems and the ever-increasing proportion of vulnerable patients contracting HAIs, a Water Management Program that addresses the prevention of HAIs that addresses system design, installation and water treatment is a priority in order to minimize the risk of patients’ acquiring an infection and the potential accompanying liability.

Note: HAI is an acronym originally used for Hospital-Acquired Infection. In recent years, HAI has also been used as an acronym for Healthcare-Acquired Infection.


Contact Legionella Control Systems for Legionella testing and a Legionella risk assessment.