Introduction to Healthcare-Associated Infections (HAIs)

Healthcare-associated infections (HAIs), also referred to as “nosocomial” or “hospital” infections, are infections that occur in a patient during the process of care in a hospital or other health care facility, which was not present or incubating at the time of admission and are a persistent challenge for healthcare practitioners and facilities around the world. The European Centre for Disease Prevention and Control (ECDC) reports that 98,000 patients in hospitals, and 130,000 residents of long-term care facilities, have at least one healthcare-associated infection whilst US Department of Health data reports about 1 in 25 inpatients have an infection related to hospital care at any given time in the United States. Millions of people a year face infections related to healthcare procedures or treatments, and more than half of certain HAIs are considered preventable. These infections lead to tens of thousands of deaths and cost health care systems billions of dollars each year. To combat and minimise these infections researchers are actively gathering data and performing analyses that generate better guidelines for preventing HAIs.

Types of Healthcare-Associated Infections

There are numerous types of healthcare-associated infections. Here are four of the most common:

  1. Central Line-associated Bloodstream Infection (CLABSI) — Of all the healthcare-associated infections, CLABSIs are associated with high-cost burden, accounting for approximately $46,000 per case. This is significant because most cases of CLABSI are preventable with proper clinical strategies including; proper precautions and practices for insertion and maintenance of central lines, hand hygiene, adherence to aseptic technique, sterilization/sterile barrier precautions, and more.
  2. Catheter-associated Urinary Tract Infections (CAUTI) — Urinary tract infections (UTIs) can occur in any part of the urinary system, and catheter-associated urinary tract infections are the fifth most common type of healthcare-associated infection. To prevent these infections, for appropriate urinary catheter use that relate to appropriate use, insertion, alternative options for high-risk patients, and general protocol around hygiene.
  3. Surgical Site Infection (SSI) —  Surgical site infections are reported as the second most common HAI in Europe and the United States of America (USA). In Europe, SSI affects more than 500 000 people per year, costing €19 million; in the USA, SSI contributes to patients spending more than 400 000 extra days in hospital, costing US$ 10 billion a year. SSIs may be superficial or extend to tissue beneath skin, organs, or implanted material. SSIs are usually identified between days seven to 11 of postoperative hospital days, and experts estimate that as many as 60% of SSIs are preventable using evidence-based guidelines. relate  to both direct and indirect surveillance and processes that occur before incision and in follow up treatment.
  4. Ventilator-associated Pneumonia (VAP) — This lung infection is the result of pneumonia developing in a person who is on a ventilator and is one of the most common causes of nosocomial infections and death in the intensive care unit. The most common route of infection is a result of germs entering through the ventilator tube. Strategies for avoiding this type of HAI encompass surveillance and detection, and can include minimizing the use of sedatives, pairing breathing trials with daily spontaneous awakening, lowering tidal volume ventilation, restrictive transfusion thresholds, and more.
  5. Clostridium difficile infections (C. diff) – C.diff begins as bacteria and is often the side-effect of antibiotics, including the drugs used for treatment of CDI: metronidazole and vancomycin. C.diff typically occurs in people 65 years and older, people who have weakened immune systems, and people who are in hospitals or nursing care centers for an extended period of time. C.diff can quickly spread and is one of the most significant nosocomial infections in hospital wards and an imminent threat to a medical care community. 

Healthcare-Associated Infection Research

There is medical research and stated guidelines that address all common types of healthcare-associated infection. Even with this dedicated progress, the ECDC acknowledges that, every day, around one out of every 15 hospital patients has at least one healthcare-associated infection.

Many of the global guidelines for HAIs have not been updated in the last ten years. It is important that researchers continue to strive to delineate best practices, which can be implemented by healthcare providers.

Here are some examples of research being conducted to better understand and prevent these types of infections:

  • The World Health Organization (WHO) published a new manual in September 2021 on “Strengthening infection prevention and control in primary care. The manual is a collection of existing standards and implementation resources for primary care providers.
  • study sponsored by a university hospital in northeast Brazil evaluated the quantity of antimicrobials prescribed in hospitals which directly impact antimicrobial resistance. According to researchers, as many as 50% of antimicrobials prescribed are inappropriate or unnecessary, and these research efforts support global efforts for antimicrobial stewardship programs (ASPs).

The goal of defining and implementing the best tactics for preventing healthcare-associated infection is prioritized by organizations that value patient care.

Patient Safety

During the COVID-19 pandemic, medical experts tracked a significant increase in healthcare-associated infections. Quoted by the Society for Healthcare Epidemiology of America, the CDC’s Associate Director of Healthcare-Associated Infection Prevention Programs, Arjun Srinivasan, M.D., said, “COVID-19 created a perfect storm for antibiotic resistance and healthcare-associated infections in healthcare settings.”

Major increases were observed in CLABSI, CAUTI, and VAP, as well as in antibiotic resistant staphylococcus infections. The largest rate increase was in central line infections due to long periods of hospitalization, up by 46% to 47% in the third and fourth quarters of 2020 compared to 2019, closely followed by ventilator-associated infections up by 45%.

In contrast, surgical-site infections rates did not increase as fewer elective surgeries were performed and no increase was found in C. diffpossibly due to an increased focus on hand hygiene, environmental cleaning, patient isolation, and use of personal protective equipment.

Dr. Srinivasan went on to explain, “Strengthening infection prevention and control capacities works. [New data about HAIs] emphasizes the importance of building stronger, deeper and broader infection control resources throughout healthcare that will not only improve our ability to protect patients in future pandemics but will also improve patient care every day.”

Patient safety should always be a priority. At Allucent, our work is driven by patient-centric study designs and execution. To learn how Allucent is creating a healthier world, contact our team.


As an infectious disease-focused CRO, Allucent has extensive experience conducting clinical trials in some of the most serious HAIs including clostridium difficile infections and ventilator-associated pneumonia.

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