Nosocomial Infection – Prevention, Source, Transmission

A nosocomial infection, also known as a hospital-acquired infection, is an infection that a patient contracts during the course of receiving treatment for another condition in a healthcare setting such as a hospital, nursing home, or clinic. Nosocomial infections have been a significant problem throughout history, with reports of healthcare-associated infections dating back to the ancient civilizations of Egypt and Greece. In the late 19th and early 20th centuries, the advent of antibiotics led to significant progress in the control of nosocomial infections, but the increasing prevalence of antibiotic-resistant organisms has made them a major public health challenge once again.

What is a nosocomial infection?

The nosocomial infection is a type of infection which mainly occurs in hospitals or other medical facilities. Nosocomial infection is also known as hospital-acquired infection (HAI). The term nosocomial is derived from the Greek words “nosos”, which means “disease,” and komeo, meansg “to take care of.”

This type of infection only contracted in a hospital environment. This infection affects all the patients, health-care-associated infections (HAI) can affect nurses, physicians, aides, visitors, salespeople, delivery personnel, custodians, and anyone else who has contact with the hospital.

Definition of Nosocomial Infection

Nosocomial infections are produced by the infectious pathogen that developed within a hospital or other type of medical care facility and is acquired by patience while they are in their facility.

Example of Nosocomial infection

A small group of organisms Responsible for this Infection, including

• Methicillin-resistant Staphylococcus aureus
• Candida albicans
• Pseudomonas aeruginosa
• Acinetobacter baumannii’
• Stenotrophomonas maltophilia
• Clostridium difficile
• Escherichia coli
• Tuberculosis
• Vancomycin-resistant Enterococcus
  Legionnaires‘ disease

Epidemiology of Nosocomial Infections 

Nosocomial infections are a significant public health problem, affecting millions of patients every year worldwide. The incidence of nosocomial infections varies widely depending on the type of healthcare facility, the patient population being served, and the specific infection. Some common types of nosocomial infections include urinary tract infections, surgical site infections, pneumonia, bloodstream infections, and Clostridium difficile infections.

Risk factors for nosocomial infections include older age, longer hospital stays, weakened immune systems, the presence of indwelling medical devices such as catheters or ventilators, and the use of antibiotics. Patients who are immunocompromised or have chronic diseases such as diabetes, cancer, and kidney or lung disease are particularly vulnerable to nosocomial infections.

Effective prevention and control of nosocomial infections requires a multi-disciplinary approach, including vigilant hand hygiene, appropriate use of antibiotics, proper cleaning and disinfection of medical equipment and surfaces, and effective infection control practices. Additionally, rapid identification and isolation of infected patients can help prevent the spread of nosocomial infections to other patients and healthcare workers.

Source of Nosocomial Infection

Nosocomial Infection divided into two classes based on their source

1. Exogenous infections
2. Endogenous infections

Exogenous infections

The source of this type of pathogen is patient, visitors, nurse, or others who enter into the hospital facility.

This type of pathogen can be transmitted by insects, from fomites to patients, equipment used in respiratory or intravenous therapy, catheters, bathroom fixtures and soap, and water systems, also can be a source of exogenous infections.

Endogenous infections

This type of infections is caused by opportunists among the patient’s own normal microflora. In this type the source of pathogen is the patient’s own microbiota.

Nosocomial infections treatment

The treatment procedure of nosocomial infection is varies based on the type of infection. The doctor will be recommended antibiotics and bed rest.

Risk for Nosocomial Infection

1. The patients in hospitals are much more susceptible to this infection. Many patients have breaks in the skin (membranes like surgical and accidental wounds, or bed sores) and mucous. The lack of intact skin and mucous membranes will help to easy access for infectious organisms. Sometimes patient’s immune system remains weak, the pathogen can take this advantage and can cause infection
2. The Roommate of a patient can be infected with nosocomial infection.
3. Elderly people, especially those over the age of 70 who are inside the treatment facility, have a higher risk of nosocomial infections.

Types of Nosocomial Infections

There are numerous causes of nosocomial infection. They depend on the infection’s type or origin, the pathogen that gave rise to it, and whether it is bacterial, fungal, or viral. The most common types of infections are pneumonia brought on by a ventilator, urinary tract infections brought on by catheters, and infections at surgical sites.

Central line associated bloodstream infections (CLABSIs)

• Central line associated bloodstream infections (CLABSIs) are a type of nosocomial infection that occur when bacteria or other pathogens enter the bloodstream through a central venous catheter, a type of medical device that is inserted into a large vein to provide access for medical procedures or for administration of medications, fluids, or nutrition.
• CLABSIs are a serious concern because they can lead to sepsis, a potentially life-threatening condition in which bacteria spread throughout the body and trigger a widespread inflammatory response. CLABSIs are also associated with increased healthcare costs and longer hospital stays.
• Risk factors for CLABSIs include the length of time a central venous catheter is in place, the type of catheter used, and the patient’s underlying health condition.
• Effective prevention strategies for CLABSIs include proper hand hygiene, use of full-barrier precautions when inserting or accessing the catheter, regular monitoring of the catheter site for signs of infection, and prompt removal of the catheter when it is no longer needed.
• Additionally, the use of evidence-based bundles of care, which are a set of best practices for catheter insertion and maintenance, has been shown to significantly reduce the incidence of CLABSIs.

Catheter associated urinary tract infections (CAUTI)

• Catheter-associated urinary tract infections (CAUTIs) are a type of nosocomial infection that occur when bacteria enter the urinary tract through a urinary catheter. A urinary catheter is a flexible tube that is inserted into the bladder to drain urine.
• CAUTIs are a common healthcare-associated infection and can lead to serious complications, such as sepsis and kidney damage. CAUTIs are also associated with increased healthcare costs and longer hospital stays.
• Risk factors for CAUTIs include the length of time a urinary catheter is in place, the type of catheter used, and the patient’s underlying health condition.
• Effective prevention strategies for CAUTIs include proper hand hygiene, use of full-barrier precautions when inserting or accessing the catheter, regular monitoring of the catheter site for signs of infection, and prompt removal of the catheter when it is no longer needed.
• Additionally, the use of evidence-based bundles of care, which are a set of best practices for catheter insertion and maintenance, has been shown to significantly reduce the incidence of CAUTIs.

Surgical site infections (SSIs)

• Surgical site infections (SSIs) are a type of nosocomial infection that occur when bacteria or other pathogens infect the incision site after surgery. SSIs can occur within 30 days of the procedure or up to one year after the procedure, depending on the type of surgery.
• SSIs can cause serious complications, including prolonged hospital stays, increased healthcare costs, and in severe cases, sepsis. SSIs are also associated with increased morbidity and mortality rates.
• Risk factors for SSIs include the type of surgery performed, the patient’s underlying health condition, and factors related to the surgical procedure, such as the use of contaminated instruments or improper wound care.
• Effective prevention strategies for SSIs include proper hand hygiene, use of full-barrier precautions during the procedure, use of prophylactic antibiotics, and proper wound care after the procedure.
• Additionally, the use of evidence-based bundles of care, which are a set of best practices for preventing SSIs, has been shown to significantly reduce the incidence of SSIs.

Ventilator associated pneumonia (VAP)

• Ventilator-associated pneumonia (VAP) is a type of nosocomial infection that occurs when bacteria or other pathogens enter the lungs and cause pneumonia in a patient who is on mechanical ventilation. Mechanical ventilation is a procedure in which a machine is used to help a patient breathe.
• VAP is a serious concern because it can lead to sepsis and other serious complications, and it is also associated with increased healthcare costs and longer hospital stays.
• Risk factors for VAP include the length of time a patient is on mechanical ventilation, the type of ventilation device used, and the patient’s underlying health condition.
• Effective prevention strategies for VAP include proper hand hygiene, use of full-barrier precautions when inserting or accessing the ventilation device, regular monitoring of the patient’s oral and respiratory tract for signs of infection, and the use of oral care protocols to prevent oral colonization with bacteria.
• Additionally, the use of evidence-based bundles of care, which are a set of best practices for preventing VAP, has been shown to significantly reduce the incidence of VAP.

Other Types

1. Clostridium difficile infections: infections caused by a bacterium that can lead to diarrhea and colitis, particularly in patients who have recently taken antibiotics.
2. Methicillin-resistant Staphylococcus aureus (MRSA) infections: infections caused by a strain of staph bacteria that is resistant to many antibiotics.
3. Vancomycin-resistant Enterococcus (VRE) infections: infections caused by bacteria that are resistant to the antibiotic vancomycin, and are particularly common among patients with weakened immune systems.
4. Candida infections: infections caused by yeast, particularly in patients who are on broad-spectrum antibiotics or who have weakened immune systems.

It is important to note that not all nosocomial infections are caused by bacteria. Other pathogens such as viruses, fungi, and parasites can also cause nosocomial infections.

Transmission of Nosocomial Infection

Hospital-acquired infection can be transmitted by all modes of transmission that occur in the community, such as;

1. Contact transmission

The most important and common transmission pathway for nosocomial infection is contact with the infected patient.

There are presently two types of contact transmissions such as:

Direct contact transmission, in this type of transmission the pathogen can be transmitted from an infected person to a normal person when the person came in direct contact with the body surface of the patient.

Indirect contact transmission, in this type the pathogen can be transmitted when a normal person came in contact with a contaminated intermediate object (usually inanimate) from infected patients. For example, contaminated instruments, needles, or dressings, or contaminated gloves that are not changed between patients, saline flush syringes, vials, and bags, etc.

2. Droplet

Droplets mainly produce during coughing, sneezing, and talking. Nosocomial infection can be transmitted throughs if the droplets contain infectious pathogens from the infected person.

3. Airborne transmission

The nosocomial infection pathogen can be transmitted through droplet nuclei (The remaining particles after the evaporation of the droplet) or dust particle which are remain suspended in the air

4. Vehicle transmission

This type of pathogen can be transmitted from a host to a person through inanimate objects, such as food, water, medications, devices, and equipment.

5. Vector-borne transmission

In this type, the pathogens are transmitted through living objects such as mosquitoes, flies, rats, etc.

Pathogens Responsible for Nosocomial

Bacteria, viruses, and fungal parasites cause nosocomial infections. These microorganisms vary according on the patient demographic, healthcare facility, and even the environment in which care is administered.

Bacteria causing Nosocomial Infections

The bacteria that cause nosocomial infections vary depending on the type of infection and the patient population. Some of the most common bacteria that cause nosocomial infections include:

• Gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa
• Gram-positive bacteria, such as Staphylococcus aureus (including methicillin-resistant S. aureus or MRSA), Streptococcus pyogenes, and Enterococcus species
• Multidrug-resistant organisms (MDROs), such as carbapenem-resistant Enterobacteriaceae (CRE) and methicillin-resistant Staphylococcus aureus (MRSA)

It is important to note that many nosocomial infections are caused by multiple bacteria and that the emergence of antibiotic-resistant strains of bacteria has made the control of nosocomial infections even more challenging. Effective infection control and prevention strategies, including hand hygiene, environmental cleaning, proper use of personal protective equipment, and the use of evidence-based bundles of care, are important in reducing the transmission of nosocomial infections.

Viruses causing Nosocomial Infections

Viruses can also cause nosocomial infections, although they are less common than bacterial infections. Some of the most common viruses that can cause nosocomial infections include:

• Hepatitis B virus (HBV)
• Hepatitis C virus (HCV)
• Human immunodeficiency virus (HIV)
• Influenza virus
• Norovirus
• Respiratory syncytial virus (RSV)
• Herpes simplex virus (HSV)

Nosocomial viral infections can occur through various routes of transmission, including direct contact with an infected patient or contaminated surfaces, airborne transmission, and exposure to contaminated medical equipment or devices. Effective infection control and prevention strategies, including hand hygiene, environmental cleaning, proper use of personal protective equipment, and the use of evidence-based bundles of care, are important in reducing the transmission of nosocomial viral infections.

Fungal parasites causing Nosocomial Infections

Fungi can also cause nosocomial infections, although they are less common than bacterial infections. Some of the most common fungi that can cause nosocomial infections include:

• Candida species, including Candida albicans and Candida glabrata
• Aspergillus species
• Cryptococcus species

Nosocomial fungal infections can occur in patients who are immunocompromised, have long-term indwelling medical devices, or have been treated with broad-spectrum antibiotics. Risk factors for nosocomial fungal infections include a prolonged hospital stay, the presence of a central venous catheter or indwelling urinary catheter, the use of mechanical ventilation, and a previous history of nosocomial infections.

Effective infection control and prevention strategies, including hand hygiene, environmental cleaning, proper use of personal protective equipment, and the use of antifungal prophylaxis in high-risk patients, are important in reducing the transmission of nosocomial fungal infections. Additionally, the prompt diagnosis and treatment of nosocomial fungal infections are critical to improve patient outcomes.

Determinants

Nosocomial infections are a major concern in healthcare facilities, as they pose a threat to patients’ health and wellbeing. These infections are acquired during a hospital stay, and can spread rapidly due to the close proximity of patients, staff, and medical equipment. To effectively combat nosocomial infections, it’s crucial to understand the key risk factors that contribute to their spread. In this article, we will explore the environmental, susceptibility, and awareness factors that increase the risk of nosocomial infections.

1. Environmental Factors

One of the biggest environmental factors that contributes to nosocomial infections is poorly maintained medical facilities. This can include insufficient waste removal, dirty surfaces, and inadequate ventilation systems. All of these factors can provide the perfect breeding ground for bacteria and viruses that can lead to infections. To reduce the risk of nosocomial infections, it’s important to ensure that medical facilities are regularly cleaned and disinfected, and that proper waste disposal practices are in place.

2. Susceptibility Factors

Patients are more susceptible to nosocomial infections when they have weakened immune systems. This can be due to a variety of reasons, including long-term use of antibiotics, immune suppression, and extended stays in the ICU. To reduce the risk of nosocomial infections in these patients, healthcare facilities must take extra precautions, such as implementing isolation measures and ensuring that staff are properly trained in infection control procedures.

3. Awareness Factors

Another major factor that contributes to nosocomial infections is the lack of awareness among medical staff and professionals. This can include the incorrect use of injection techniques, an inadequate understanding of fundamental infection control procedures, the improper use of invasive devices (such as catheters), and a lack of control policies. To reduce the risk of nosocomial infections, it’s important to educate and train staff on proper infection control procedures, and to implement strict policies and procedures to ensure that they are followed.

In conclusion, nosocomial infections are a major concern in healthcare facilities, and are often caused by environmental, susceptibility, and awareness factors. To reduce the risk of nosocomial infections, it’s crucial to ensure that medical facilities are properly maintained, that patients’ immune systems are protected, and that staff are properly trained and aware of infection control procedures. By addressing these risk factors, we can work to prevent the spread of nosocomial infections and ensure that patients receive the safe and high-quality care they deserve.

Reservoirs and transmission of Nosocomial Infections

In this article, we will explore the various reservoirs and modes of transmission for nosocomial infections and the measures that can be taken to reduce the risk of infection.

1. Microflora of the Patient: The human body is home to a vast array of microorganisms, known as the microflora. This microflora includes bacteria, viruses, and other pathogens that can cause infections when transferred to tissue wounds or surgical sites. Gram-negative bacteria are particularly concerning as they have been linked to surgical site infections (SSIs) following abdominal surgery in the digestive tract.
2. Patient and Staff: The transmission of pathogens between patients and healthcare providers is a significant concern. Direct contact with patients, such as through hands, saliva, or other bodily fluids, can lead to the transfer of pathogens. Similarly, staff members can transmit pathogens through direct contact with patients or by carrying pathogens on their clothing, equipment, or food.
3. Environment: The healthcare environment is another significant source of nosocomial infections. Water, food, and equipment used in healthcare facilities can all contain pathogens that can spread disease. Additionally, the close proximity of patients in healthcare facilities increases the risk of transmission from one patient to another.

Preventions of Nosocomial Infections

Nosocomial infections, also known as hospital-acquired infections, can be prevented through the following measures:

1. Hand hygiene: Regular hand washing or use of alcohol-based hand sanitizers is essential to prevent the spread of germs.
2. Isolation: Patients with infectious diseases should be kept in isolation to prevent the spread of the infection to other patients.
3. Sterilization and Disinfection: Equipment and surfaces in the hospital should be regularly cleaned and disinfected to prevent the spread of infection.
4. Use of Personal Protective Equipment (PPE): Healthcare workers should use PPE, such as gloves, masks, and gowns, when caring for patients with infectious diseases.
5. Vaccination: Healthcare workers and patients should be vaccinated against infectious diseases such as influenza, hepatitis B, and varicella.
6. Proper use of antibiotics: Antibiotics should be prescribed only when necessary and used as directed to prevent the development of antibiotic-resistant bacteria.
7. Proper disposal of medical waste: Infectious medical waste should be disposed of properly to prevent the spread of disease.

By following these measures, healthcare facilities can help to prevent nosocomial infections and improve patient safety.

Control of Nosocomial Infections

Control of nosocomial infections requires a comprehensive and ongoing effort, including the following measures:

1. Surveillance: Regular monitoring of infections in the hospital to identify outbreaks and track the effectiveness of control measures.
2. Infection Prevention Teams: The formation of infection prevention teams, consisting of healthcare workers and infection control specialists, to develop and implement strategies to prevent nosocomial infections.
3. Standard Precautions: Adherence to standard precautions, such as hand hygiene, use of personal protective equipment, and sterilization and disinfection, to prevent the spread of infections.
4. Antibiotic Stewardship Programs: Implementation of programs to optimize the use of antibiotics and prevent the development of antibiotic-resistant bacteria.
5. Education and Training: Ongoing education and training for healthcare workers to keep them informed of the latest infection control practices and technologies.
6. Environmental Control: Maintenance of a clean and safe environment in the hospital, including proper ventilation and lighting, to reduce the risk of infections.
7. Reporting and Response: Reporting of infections to public health authorities and prompt response to outbreaks to contain the spread of infections.

By following these control measures, healthcare facilities can effectively manage and reduce the risk of nosocomial infections.

Sites of Nosocomial Infection

Nosocomial infection can be occurring in these following sites of a person, such as urinary tract, surgical wounds, respiratory tract, skin (especially burns), blood (bacteremia), gastrointestinal tract, and central nervous system.

Conclusion: Nosocomial infections are a serious threat to patient health and require a multi-faceted approach to reduce the risk of transmission. Understanding the sources of nosocomial infections, such as the microflora of the patient, direct patient-staff contact, and the healthcare environment, is essential in developing effective infection control measures. By implementing proper infection control practices and procedures, healthcare providers can reduce the risk of nosocomial infections and ensure the safety of their patients.

Facts about Nosocomial Infection

Here are some interesting and mind-blowing facts about Nosocomial Infections:

1. Nosocomial infections are a serious public health problem worldwide, affecting millions of patients every year.
2. These infections are acquired in healthcare facilities such as hospitals and nursing homes, and are often caused by bacteria, viruses, and fungi that are resistant to antibiotics.
3. Some of the most common nosocomial infections include urinary tract infections, pneumonia, bloodstream infections, and surgical site infections.
4. The risk of nosocomial infections is increased by factors such as prolonged hospital stays, the use of invasive medical devices, and weakened immune systems.
5. In some countries, nosocomial infections are the fourth leading cause of death and can result in significant economic costs, including increased healthcare expenses and lost productivity.
6. Effective infection control measures, such as proper hand hygiene, environmental cleaning, and the use of personal protective equipment, are crucial in preventing the spread of nosocomial infections.
7. Research has shown that investments in infection prevention and control programs can lead to significant reductions in the incidence of nosocomial infections, as well as lower healthcare costs and improved patient outcomes.

FAQ on Nosocomial Infections

Reference

• CDC,”NI Surveillance, 1984“
• Wikipedia, “Hospital-acquired infection“
• Amboss,”NI (Hospital-acquired infections)” last updated 06/08/2020
• Healthline, “Nosocomial Infections“
• Prescott’s Microbiology by Joanne Willey (Author), Linda Sherwood (Author), Christopher J. Woolverton (Author)