World Patient Safety Day, which falls on September 17 every year, is, according to the World Health Organization, an opportunity to raise public awareness, foster collaboration between stakeholders and mobilise global action to improve patient safety. One of many common adverse events that can impact safety are hospital-acquired infections (HAIs), also known as as nosocomial infections.

Here is all you need to know about them.

What are HAIs?

Hospital-acquired or healthcare setting acquired-infections (HAIs) are infections that you contract at a medical facility while you are being treated for another condition. These are infections that were not present at admission to the facility. They can be acquired in a range of healthcare settings: hospitals, clinics, dialysis centres, and a long-term care facilities among others.

The World Health Organization, in its 2002 guide, Prevention of hospital-acquired infections, 2nd edition defines HAIs as: an infection acquired in hospital by a patient who was admitted for a reason other than that infection. An infection occurring in a patient in a hospital or other health care facility in whom the infection was not present or incubating at the time of admission. This includes infections acquired in the hospital but appearing after discharge, and also occupational infections among staff of the facility. In general, HAIs are considered to be those that develop after 48 hours of hospital admission or within 30 days of a surgical procedure.

Such infections are a significant source of avoidable harm in healthcare settings globally.

The true cost of hospital-acquired infections Types of HAIs

There are many different types of HAIs. They can be due do bacteria, viruses or fungi, with bacterial infections being the most common.

Common pathogens include: gram negative bacteria such as Staphylococci, Staphylococcus aureus, Streptococcus species, and the Enterococcus species. Clostridioides difficile (C. diff), is one of the most frequently-identified organisms in hospital acquired infections. It can cause colon inflammation and a very contagious form of diarrhoea. Staphylococcus aureus that is resistant to common antibiotics such as penicillin, amoxicillin and methicillin is known as Methicillin-resistant Staphylococcus aureus or MRSA. These multi-drug resistant bacteria are associated with significant mortality. Gram-negative bacteria include members of the Enterobacteriaceae family (eg, Klebsiella pneumoniae and Klebsiella oxytoca, Escherichia coli, Proteus mirabilis, and Enterobacter species), Pseudomonas aeruginosa, Burkholderia cepacia, and Acinetobacter baumanii. These bacteria may cause bloodstream infections, meningitis or pneumonia.

Fungal pathogens of the Candida species are the common fungal agents causing infections. Even with fungal infections, multi-drug resistance is emerging as a concern.

Viral infections, while less common include hepatitis infections as well as HIV, among others.

Post-surgical infections more likely due to skin bacteria than hospital bugs, study findsHow they are transmitted

HAIs can be transmitted via respiratory droplets; they can also spread when proper sterilisation and infection control procedures are not followed; through contaminated equipment; during invasive procedures and via endogenous flora (microorganisms naturally present in an environment such as the human body).

There are some risk factors when it comes to nosocomial infections. If the treatment involves invasive procedures and surgeries, the use of catheters or ventilators and implants, the risks are higher.

According to the Centers for Disease Control and Prevention, U.S., hospital-acquired infections inlcude:

Central line-associated Bloodstream Infection (CLABSI): These are infections acquired when germs pass through a central line or a catheter that is often placed in a large vein and enter the bloodstream. These are different from peripheral IVs, as they access a major vein and can remain in place for much longer than an IV.

Catheter-associated Urinary Tract Infection (CAUTI): This occurs when pathogens enter the urinary tract and cause an infection. The infection can affect any part of the urinary tract.

Surgical site infections (SSI): This is an infection in the part of the body where the surgery took place. They can occur in the skin, tissue, organs or in materials that were implanted during the procedure.

Ventilator-associated pneumonia: This is a lung infection that develops when a person is on a ventilator.

AIIMS-led study finds infections contracted in hospital due to catheter use prevalent across IndiaPrevention

Hospital-acquired infections contribute to illnesses and deaths, significantly impacting morbidity, mortality and costing millions to healthcare systems. According to the WHO, these are among the most frequent adverse events occurring in the context of health service delivery. In 2022, the WHO said, out of every 100 patients in acute-care hospitals, seven patients in high-income countries and 15 patients in low- and middle-income countries will acquire at least one health care-associated infection during their hospital stay. On average, 1 in every 10 affected patients will die from their HAI.

Infection prevention and control (IPC) interventions are proven to reduce HAIs and antimicrobial resistance by 35-70% and are cost saving, irrespective of the level of income of a country, according to the WHO. High quality water, sanitation and hygiene services, effective IPC programmes, based on the WHO core components, including hand hygiene action, can reduce HAIs by up to 70%, it states.

Making health care safe for every IndianIndian scenario

In a study published in The Lancet Global Health in 2022, Health-care-associated bloodstream and urinary tract infections in a network of hospitals in India: a multicentre, hospital-based, prospective surveillance study, which involved 26 tertiary-level hospitals in India pooled in a network to implement HAI surveillance and prevention, Purva Mathur et al found 2,622 health-care-associated bloodstream infections and 737 health-care-associated UTIs from 89 intensive care units (ICUs) between May 1, 2017, and October 31, 2018. Central line-associated bloodstream infection rates were highest in neonatal ICUs. Catheter-associated UTI rates were highest in paediatric medical ICUs. Klebsiella spp (24·8%) were the most frequent organism in bloodstream infections and Candida spp (29·4%) in UTIs, the study found. The authors also reported high levels of Carbapenem (a class of powerful antibiotics) resistance.

A comment in the same publication that year by Manoj V. Murhekar and C.P. Girish Kumar noted that the risk of acquiring HAI is up to 20 times higher in LMICs. "In India, a large segment of the population seeks in-patient health-care at secondary or district-level health facilities in public and private sectors, many of which have inadequate infection prevention and control measures. The major barriers to infection prevention and control implementation are scarcity of dedicated and trained staff, availability and inappropriate use of PPE, and sanitary and hygiene measures, compounded with patient overcrowding," the authors stated.

All you need to know about: hospital-acquired infections