Infection Prevention and Control

Introduction

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According to the World Health Organization (WHO), infection prevention and control (IPC) is a scientific approach and practical solution designed to prevent harm caused by infection to patients and health workers. It is a subset of epidemiology, but also serves an essential function in infectious diseases, social sciences and global health[1].

Effective IPC is a public health issue that is fundamental in patient safety and health system strengthening. The prevention of healthcare-associated infections (HAI), epidemics (including the 2013-2016 Ebola virus disease outbreak), and pandemics of international concern (i.e. 2009 flu pandemic and the coronavirus disease 2019) are rooted in effective IPC measures[2]. A guiding principle on WHO's core components of IPC is that "access to health care services designed and managed to minimise the risks of avoidable HAI for patients and health care workers is a basic human right"[2].

The Spread of Infectious Disease

An infection is defined as the successful transmission of pathogenic microorganisms, such as bacteria, viruses, parasites or fungi that are spread:[3][4][5]

  • Directly:
    • From person to person.
    • Through respiratory droplets (i.e. coughing or sneezing) or body fluids.
    • During childbirth from mother to foetus.
  • Indirectly:
    • Via contaminated environmental sources, such as contaminated food or water.
    • By a vector such as a mosquito or a tic.
    • Through animal to human transmission (zoonotic diseases).
    • Airborne transmission.

Epidemiological Triad

In humans, infections occur when an infectious microorganism enters the body, multiplies, and leads to a reaction in the body and potential infectious disease. The spread of infectious disease requires three variables, known as the epidemiological triad[6]:

  • The agent - this microorganism that causes the infection and can be in the form of bacteria, viruses, parasites or fungi.
  • The host - the target of the disease.
  • The environment - surroundings and conditions (these are external to the host).
[7]

Infection Spread in Healthcare

Healthcare facilities, whether hospitals or primary care clinics are an area with an elevated risk of disease transmission due to the presence and relative ratio of susceptible individuals. One in ten patients get an infection whilst receiving care[8] yet effective infection prevention and control reduces health care-associated infections by at least 30%[8]. In a healthcare setting, the three components required for infection spread are the following[9]:

  • Source - places where infectious agents survive (e.g. sinks, hospital equipment, countertops, medical devices).
    • Environment - patient care areas, sinks, hospital equipment, countertops, medical devices.
    • People - patients, healthcare workers, or visitors.
  • Susceptible person - someone (patient, healthcare worker, or visitor) who is not vaccinated or immune to a particular infectious disease, or an individual with a compromised immune system (ie. immunodeficient)[9].
    • In addition, susceptibility can be heightened in individuals due to underlying medical conditions, medications, and necessary treatments and procedures that increase the risk of infection (e.g. surgery).
  • Transmission -
    • Touch, including via medical equipment or a susceptible person (e.g. MRSA or VRE).
    • Sprays or splashes (e.g. pertussis).
    • Inhalation of aerosolised particles (e.g. TB or measles).
    • Sharps injuries introducing blood-borne pathogens (e.g. HIV, HBV, HCV).

Controlling Infectious Diseases Within Communities

Infection control and prevention is a global issue and there are many protocols and guidelines that can be followed to minimise the spread of infection between people, within a population and globally[2]. Identifying at-risk groups such as children, older people and those with chronic conditions can also help guide relevant strategies to protect these vulnerable groups. The first step when looking at infection control can start at the community level by changing behaviour, including:

  • Regular hand washing.
  • Using insect repellents.
  • Ensuring up-to-date routine vaccinations and participating in immunisation programmes.
  • Taking prescribed medications, such as antibiotics, as directed by health professionals.
  • Social distancing - avoiding contact with others.
  • Using condoms when having sex, especially with a new partner.

Other steps that can be taken to control the spread within communities include environmental measures such as:

  • Modifying environments.
  • Surveillance of diseases.
  • Food safety.
  • Air quality.

Medical Interventions

As well as simple steps to prevent and control infections, there are biochemical interventions that can be implemented to speed up the recovery process and in some cases prevent viral infections completely.[10] The development of antibiotics, antivirals and vaccinations have been shown to speed up recovery, slow down the progression and in some cases eradicate infectious diseases from entire populations.

Antibiotics

Antibiotics are prescribed for bacterial infections and support the body's natural defence system to eliminate the disease-causing bacterial agent. They are designed to either kill bacteria or stop them from reproducing, however poor use of antibiotics, over-prescribing and the mutation of bacteria has led the development of resistant bacteria[11]. In these cases, either stronger doses are required or the combination of one or more antibiotics.

Vaccinations

Vaccinations are designed to improve immunity to a particular disease. Vaccines work by introducing small amounts of the disease-causing virus or bacteria into the host, allowing them to build up natural immunity. The introduction of regular vaccines have slowed down and in some cases eradicated certain diseases such as polio, measles, mumps, whooping cough and rubeola (measles). There are also vaccinations for chickenpox but this is not given routinely and is reserved for those at risk of spreading the disease to those with a weakened immune system[12]. This is due to the fact that it is prevalent in children under 10 years of age and symptoms are usually mild; this method allows them to build up natural immunity and contributes to improving the immunisation of a community[13]. This type of protection is known as herd immunity[14].

Antivirals

For infectious diseases that are caused by viral agents such as influenza, HIV, herpes, and hepatitis B, antibiotics provide no defence and in these cases, antiviral medications are the most effective at slowing down the progression of the disease and boosting the immune system. Unfortunately, as with antibiotics, viruses can mutate over time and become resistant to these antiviral drugs[11].

Infection Control in Healthcare Facilities

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Another important factor in controlling and preventing the control of infection is by improving practices in healthcare facilities. It is the duty of healthcare professionals worldwide to ensure they develop strategies and implement policies that protect those who may be immunocompromised in order to keep susceptible patients safe from healthcare-associated infections (HAIs). Globally, up to 7% of patients in developed and 10% in developing countries will acquire at least one HAI[2][15].

HAIs are one of the most common detrimental effects in care delivery and both the endemic burden and the occurrence of epidemics are a major public health concern. HAIs have a significant impact on morbidity, mortality[16] and quality of life and present an economic burden at the societal level. However, a large proportion of HAI are preventable and there is a growing body of evidence to help raise awareness of the global burden of harm caused by these infections, including strategies to reduce their spread[9].

Steps to Improve Infection Control

There are two tiers of recommended precautions by the Center of Disease Control and Prevention (CDC)[17] to prevent the spread of infections in healthcare settings: (1) Standard Precautions and (2) Transmission-Based Precautions[18][5].

Standard Precautions for All Patient Care:

  • Perform hand hygiene[19][20][21]
  • Use personal protective equipment (PPE) to prevent exposure to infection
  • Follow respiratory hygiene/cough etiquette principles
  • Ensure appropriate patient placement and isolation precautions[22]
  • Properly handle, clean, and disinfect patient care equipment and medical instruments
  • Handle and sterilise textiles and laundry carefully
  • Follow safe injection practices and proper handling of sharps/needles
  • Ensure healthcare worker safety via IPC and post-exposure prophylaxis
  • Prevention of intervention-related infections (catheter-associated urinary tract infections, intravascular catheter-related infections, surgical site infections)
  • The implementation of the specific isolation precaution when diagnosing some syndromes[22]
  • Improving the communication between health care workers especially when referring potentially contagious patients[23]
  • In paediatric departments or ambulatory settings, efforts to decrease infection from contaminated toys and encouraging families to bring their own toys[23]

Transmission-Based Precautions[24] used in addition to Standard Precautions for patients with infectious disease to prevent transmission:

  • Contact Precautions
  • Droplet Precautions
  • Airborne Precautions
[25]

Further details and guidelines for transmission-based and isolation precautions are provided by the Centers for Disease Control and Prevention (CDC):

Infection Control Programmes in Acute Care

The CDC[26] suggest that the assessment and management of infection control programs and practices in acute care hospital can be divided into 4 sections:

  • Section 1: Facility Demographics
  • Section 2: Infection Control Programme and Infrastructure
  • Section 3: Direct Observation of Facility Practices (optional)
  • Section 4: Infection Control Guidelines and Other Resources

They have produced a "Infection Prevention and Control Assessment Tool for Acute Care Hospitals" that is intended to assist in the assessment of infection control programs and practices in acute care hospitals.

Environmental Cleaning/Disinfection

The evidence suggests the important role of environmental cleaning in controlling the transmission of organisms (e.g.Staphylococcus aureus, vancomycin-resistant enterococci, norovirus, Clostridium difficile and acinetobacter) especially in hospitals and health- care settings[27]

If an individual with a suspected or confirmed case of infectious disease has attended your clinic, all surfaces that the person has come into contact with must be cleaned.

  • The room where they were placed/isolated should not be cleaned or used for one hour and the door to the room should remain shut.
  • The person assigned to clean the room should wear gloves (disposable single-use nitrile or household gloves) and a disposable apron (if one is available) then physically clean the environment and furniture using a household detergent solution followed by a disinfectant or combined household detergent and disinfectant, for example, one that contains a hypochlorite (bleach solution)[28]. Products with these specifications are available in different formats including wipes.
  • No special cleaning of walls or floors is required.
  • Pay special attention to frequently touched flat surfaces, backs of chairs, couches, door handles or any surfaces that the affected person has touched.
  • Discard waste (including used tissues, disposable cleaning cloths) into a healthcare risk waste bag.
  • Remove the disposable plastic apron (if worn) and gloves and discard into a healthcare risk waste bag.
  • If a healthcare risk waste bag (yellow) is not available, place the waste in a small household waste bag and tie securely. Do not overfill. Then place the bag in a second household waste bag and tie securely. Store in a safe location.If the case is not confirmed the waste can be disposed of as per usual.If a case is confirmed public health will then advise you what to do with the waste.
  • Once this process has been completed and all surfaces are dry the room can be put back into use.

Infection Control Programmes Globally

The WHO guidelines[2] on the core components of IPC programmes at the national and facility level aim to enhance the capacity of countries to develop and implement effective technical and behaviour modifying interventions. They form a key part of WHO strategies to prevent current and future threats from infectious diseases such as Ebola, strengthen health service resilience, help combat antimicrobial resistance (AMR) and improve the overall quality of health care delivery. They are also intended to support countries in the development of their own national protocols for IPC and AMR action plans and to support health care facilities as they develop or strengthen their own approaches to IPC.

The "Executive Summary of the Minimum Requirements by Core Component" provides a good summary to present and promote the minimum requirements for IPC programmes at the national and health care facility level, identified by expert consensus according to available evidence and in the context of the WHO core components.

Improving Social Determinants

Another important factor to consider in the control of infectious diseases is to address and improve social determinants of health within societies. There is a direct link between a person's health and their environment. WHO has identified three "common interventions" for improving health conditions worldwide[29]:

  • Education - there is a strong link between health and education[30].
  • Social Protection - access to affordable health care and some form of social security system can also determine the health and behaviours in a community[31].
  • Urban Development - how our villages, towns and cities are designed can have a big impact on health and the spread of diseases. Living in overcrowded environments or in housing that is damp and/or that doesn't have adequate facilities and sanitation can increase the spread of infectious diseases[32].

Conclusion

There is no one solution to controlling the spread of infectious diseases, and effective IPC indeed requires government intervention and collaboration between healthcare agencies, individuals and communities. Until certain risk factors are addressed and behaviours modified, the war against infectious diseases will continue to be a predominant and costly health issue around the world.

Resources

The following resources expand further on the four sections mentioned above:

References

  1. Infection prevention and control [Internet]. World Health Organization. 2020 [cited 27 March 2020]. Available from: https://www.who.int/infection-prevention/about/ipc/en/
  2. 2.0 2.1 2.2 2.3 2.4 World Health Organization. Guidelines on core components of infection prevention and control programmes at the national and acute health care facility level. World Health Organization; 2016.
  3. Mayhall CG. Hospital epidemiology and infection control. Lippincott Williams & Wilkins; 2012 Feb 20.
  4. Control and Prevent the Spread of Germs [Internet]. Centers for Disease Control and Prevention. 2020 [cited 27 March 2020]. Available from: https://www.cdc.gov/infectioncontrol/index.html
  5. 5.0 5.1 Wilson J. Infection control in clinical practice. Elsevier Health Sciences; 2006 Jun 21.
  6. US Department of Health and Human Services. Principles of Epidemiology in Public Health Practice Third Edition An Introduction to Applied Epidemiology and Biostatistics. Chapter 8, Lesson 1. Atlanta, Georgia, USA Accessed 15 March 2020
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  13. Brisson, M., & Edmunds, W. J. (2003). Economic Evaluation of Vaccination Programs: The Impact of Herd-Immunity. Medical Decision Making, 23(1), 76–82. doi:10.1177/0272989x02239651 
  14. Fine PE. Herd immunity: history, theory, practice. Epidemiologic reviews. 1993 Jan 1;15(2):265-302.
  15. Sydnor ER, Perl TM. Hospital epidemiology and infection control in acute-care settings. Clinical microbiology reviews. 2011 Jan 1;24(1):141-73.
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  18. Infection Control Basics | Infection Control | CDC [Internet]. Cdc.gov. 2020 [cited 15 March 2020]. Available from: https://www.cdc.gov/infectioncontrol/basics/index.html
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  23. 23.0 23.1 McBride DL. Updated Guidelines on Infection Prevention in Pediatric Ambulatory Settings. Journal of pediatric nursing. 2018 Jan.
  24. Transmission-Based Precautions | Basics | Infection Control | CDC” [Internet]. Cdc.gov. 2020 [cited 15 March 2020]. Available from: https://www.cdc.gov/infectioncontrol/basics/transmission-based-precautions.html
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  28. Wilcox MH, Fawley WN, Wigglesworth N, Parnell P, Verity P, Freeman J. Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection. Journal of Hospital Infection. 2003 Jun 1;54(2):109-14.
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