What does chain of infection mean in medical terms?
The spread of an infection within a community is described as a “chain,” several interconnected steps that describe how a pathogen moves about. Infection control and contact tracing are meant to break the chain, preventing a pathogen from spreading.
What 3 elements are involved in the chain of infection?
The six links include: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
What is the chain of infection a model of?
This model explains the spread of a communicable disease from one host (or person) to another. The basic idea represented in the chain of infection is that individuals can break the chain (reduce the risk) at any point; thus the spread of the disease can be stopped.
What are the six components of the chain of infection?
The 6 points include: the infectious agent, reservoir, portal of exit, means of transmission, portal of entry, and susceptible host.
Why is the chain of infection important?
There are many different germs and infections inside and outside of the healthcare setting. Despite the variety of viruses and bacteria, germs spread from person to person through a common series of events. Therefore, to prevent germs from infecting more people, we must break the chain of infection.
What are the stages of infection?
There are five stages of infection:incubation.prodromal.illness.decline.convalescence.
What is the final link in the chain of infection?
The susceptible host. The last link in the chain of infection is the susceptible host.
What are the 4 routes of transmission?
The transmission of microorganisms can be divided into the following five main routes: direct contact, fomites, aerosol (airborne), oral (ingestion), and vectorborne.
What is the chain of 5 F's that can cause infection?
5 Fs that cause the spread of food borne diseases are Food (contaminated), Fingers (unclean), Faeces, Fomites, and Flies.
Which method is most effective to break the chain of infection quizlet?
One of the most effective ways to break the chain of infection is hand washing. Under Universal Precautions blood and certain body fluids from all individuals are considered potentially hazardous. Any body fluids with visible blood should be considered potentially hazardous and all appropriate PPE should be worn.
How many links are there in the chain of infection?
This process, called the chain of infection, can only occur when all six links in the chain are intact. By breaking this chain at any of the links, the spread of infection is stopped. Disease Microorganisms (Agent).
What is the body's first line of defense against infection?
The innate immune system is the body's first line of defense against germs entering the body. It responds in the same way to all germs and foreign substances, which is why it is sometimes referred to as the "nonspecific" immune system.
What 3 elements are involved in the chain of infection quizlet?
Infection occurs in a cycle that depends on the presence of all of the following elements: An Infectious Agent or Pathogen. A Reservoir or Source for Pathogen Growth. A Port of Exit from Reservoir. A Mode of Transmission. Port of Entry to A Host. A Susceptible Host.
Which three elements are required to transmit infection in a healthcare setting OSHA?
Transmission of infection within a health care setting requires three elements: a source of infecting microorganisms, a susceptible host, and a means of transmission for the microorganism to the host.
Which element is part of the chain of infection quizlet?
A susceptible host is the element in the chain of infection that receives the pathogens and is in a favorable condition for their growth and transmission.
What are the chain of infection links in order?
What are the 6 links in the chain of infection?The pathogen. The first link in the chain of infection is the infectious agent or pathogen which can take the form of: ... The reservoir. ... The portal of exit. ... The mode of transmission. ... The portal of entry. ... The susceptible host.
How many steps are there in the chain of infection?
There are six steps in the chain of infection and transmission will only take place if all six links are intact. Infectious Agent – microorganism (e.g. virus, bacteria, or fungi) Reservoir (source) – a host which allows the microorganism to live, and possibly grow, and multiply. Humans, animals and the environment can all be reservoirs ...
Why is understanding how an infection spreads important?
Understanding how the infection is spread is essential to our efforts to prevent and contain its spread, especially when there is no definitive treatment available.
How does a person get an infectious agent?
This can happen through the mouth, if a person coughs or sneezes, through a cut, if a person is bleeding, during diaper changes or toileting. Mode of Transmission – how the infectious agent is transmitted from one person to another. It can be in the form of droplets, direct or indirect contact, or through airborne transmission.
How does WHO prevent viruses?
To prevent and of viruses, WHO recommends employing basic hygiene principles through standard and transmission-based precaution.
How long does the virus stay in the air?
Although one study has reported that the virus can remain viable in the air for up to 3 hours (van Doremalen et al., 2020), more research is needed to confirm if airborne transmission ...
Why do we need to protect the patient from germs?
Why: To protect the patient agaisnt harmful germs, including the patient's own, from entering his/her body.
What is the first link in the chain of infection?
The first link in the chain of infection is the infectious agent or pathogen which can take the form of: Viruses – such as Influenza A, shingles and Hepatitis. Bacteria – including Lyme disease and Leptospirosis. Fungi – for example Candidiasis and Aspergillosis.
How can we break the chain of infection?
The healthcare environment can expose patients to infection risks that they may not encounter elsewhere.
How can an infection be transmitted from its reservoir to a susceptible host?
The two main ways that an infection can be transmitted from its reservoir to a susceptible host are via direct transmission or indirect transmission. Direct transmission tends to be instantaneous and occurs when there is direct contact with the infectious agent.
What is the habitat in which a pathogen lives, flourishes and is able to multiply?
2. The reservoir . A reservoir is the principal habitat in which a pathogen lives, flourishes and is able to multiply. Common reservoirs for infectious agents include humans, animals or insects and the environment.
Why is understanding how infections become established in healthcare settings important?
Understanding how infections become established in healthcare settings is crucial for effective infection prevention and control.
What is the term for any infectious disease that is transmitted under natural conditions from animal to human?
Any infectious disease that is transmitted under natural conditions from animal to human is referred to as zoonosis.
How well do pathogens thrive?
How well any pathogen is able to thrive depends on three factors: 2. The reservoir. A reservoir is the principal habitat in which a pathogen lives, flourishes and is able to multiply. Common reservoirs for infectious agents include humans, animals or insects and the environment.
What is the chain of infection?
The Chain of Infection. A framework that can help us to understand how infections occur is the “chain of infection” which describes the sequence of events that must occur in order for an infection to occur. This chain applies to all pathogens.
How many links are there in the chain of infection?
The chain of infection is made up of six links. Each link must align in order for an infection to occur, starting with an infectious agent such as SARS-CoV-2, the virus responsible for COVID-19. The second link is the reservoir for the infectious agent. Reservoirs can include people, environmental surfaces, water, air, and so on.
What are the three new pathogenic viruses?
According to the National Institute for Allergy and Infectious Diseases (NIH), over the past 20 years, three new pathogenic Coronaviruses have emerged from animal reservoirs. 1 They are a large family of viruses that commonly cause respiratory illnesses in people as well as in many different animal species. 2 Examples include Severe Acute Respiratory Distress Syndrome (SARS) back in 2003 and more recently, Middle Eastern Respiratory Syndrome (MERS). 2 The COVID-19 strain, genetically related to the SARS virus, has not been identified in humans until now. 3 Our lack of immunity to this virus explains its readiness to spread from person-to-person.
How can we stop infections from occurring?
The good news is that we can stop infections from occurring by breaking just one link in the chain. This can easily be accomplished through actions such as covering coughs, performing frequent hand hygiene, cleaning and disinfecting environmental surfaces routinely, and keeping current on immunizations.
How can a virus be transmitted?
And if those droplets land on and contaminate an environmental surface, the virus can potentially be transmitted by touching that surface and then rubbing one’s eyes or nose. The fifth link in the chain is the portal of entry. This is how the pathogen enters its host or a susceptible person. The portal of entry for the COVID-19 virus is ...
What are the reasons for an infection?
Reasons that the organism will cause an infection are virulence (ability to multiply and grow), invasiveness (ability to enter tissue), and pathogenicity (ability to cause disease).
What is indirect transmission?
The means by which an organism transfers from one carrier to another by either direct transmission (direct contact between infectious host and susceptible host) or indirect transmission (which involves an intermediate carrier like an environmental surface or piece of medical equipment).
What makes a person more susceptible to disease?
Several factors make a person more susceptible to disease including age (young people and elderly people generally are more at risk), underlying chronic diseases such as diabetes or asthma, conditions that weaken the immune system like HIV, certain types of medications, invasive devices like feeding tubes, and malnutrition.
How do germs spread?
Despite the variety of viruses and bacteria, germs spread from person to person through a common series of events. Therefore, to prevent germs from infecting more people, we must break the chain of infection. No matter the germ, there are six points at which the chain can be broken and a germ can be stopped from infecting another person.
How to stop germs from spreading?
The way to stop germs from spreading is by interrupting this chain at any link. Break the chain by cleaning your hands frequently, staying up to date on your vaccines (including the flu shot), covering coughs and sneezes and staying home when sick, following the rules for standard and contact isolation, using personal protective equipment the right way, cleaning and disinfecting the environment, sterilizing medical instruments and equipment , following safe injection practices , and using antibiotics wisely to prevent antibiotic resistance. Learn 10 ways to protect patients.
How many points in the chain of infection can be broken?
Therefore, to prevent germs from infecting more people, we must break the chain of infection. No matter the germ, there are six points at which the chain can be broken and a germ can be stopped from infecting another person. The six links include: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, ...
What is the portal of exit?
Portal of exit is the way the infectious agent leaves the reservoir (through open wounds, aerosols, and splatter of body fluids including coughing, sneezing, and saliva)
What are the six links of a pathogen?
The six links include: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host . Reservoir includes places in the environment where the pathogen lives (this includes people, animals and insects, medical equipment, and soil and water)
How does airborne transmission occur?
Airborne transmission occurs when infectious agents are carried by dust or droplet nuclei suspended in air. Airborne dust includes material that has settled on surfaces and become resuspended by air currents as well as infectious particles blown from the soil by the wind. Droplet nuclei are dried residue of less than 5 microns in size. In contrast to droplets that fall to the ground within a few feet, droplet nuclei may remain suspended in the air for long periods of time and may be blown over great distances. Measles, for example, has occurred in children who came into a physician’s office after a child with measles had left, because the measles virus remained suspended in the air. ( 46)
What is the name of the virus that causes dengue fever?
Dengue and dengue hemorrhagic fever are caused by any one of four closely related flaviviruses, designated DEN-1, DEN–2, DEN-3, or DEN-4.
Why is droplet spread considered direct?
Droplet spread is classified as direct because transmission is by direct spray over a few feet, before the droplets fall to the ground. Pertussis and meningococcal infection are examples of diseases transmitted from an infectious patient to a susceptible host by droplet spread.
How is vectorborne transmitted?
Vectorborne (mechanical or biologic) In direct transmission, an infectious agent is transferred from a reservoir to a susceptible host by direct contact or droplet spread. Direct contact occurs through skin-to-skin contact, kissing, and sexual intercourse.
What is reservoir in infectious agents?
Reservoir. The reservoir of an infectious agent is the habitat in which the agent normally lives, grows, and multiplies. Reservoirs include humans, animals, and the environment. The reservoir may or may not be the source from which an agent is transferred to a host. For example, the reservoir of Clostridium botulinum is soil, ...
What is the pathogen triad?
As described above, the traditional epidemiologic triad model holds that infectious diseases result from the interaction of agent, host, and environment . More specifically, transmission occurs when the agent leaves its reservoir or host through a portal of exit, is conveyed by some mode of transmission, and enters through an appropriate portal of entry to infect a susceptible host. This sequence is sometimes called the chain of infection.
What is a carrier in a human reservoir?
As noted earlier, a carrier is a person with inapparent infection who is capable of transmitting the pathogen to others. Asymptomatic or passive or healthy carriers are those who never experience symptoms despite being infected. Incubatory carriers are those who can transmit the agent during the incubation period before clinical illness begins. Convalescent carriers are those who have recovered from their illness but remain capable of transmitting to others. Chronic carriers are those who continue to harbor a pathogen such as hepatitis B virus or Salmonella Typhi, the causative agent of typhoid fever, for months or even years after their initial infection. One notorious carrier is Mary Mallon, or Typhoid Mary, who was an asymptomatic chronic carrier of Salmonella Typhi. As a cook in New York City and New Jersey in the early 1900s, she unintentionally infected dozens of people until she was placed in isolation on an island in the East River, where she died 23 years later. ( 45)
Why is a personal who becomes ill after pathogens enter the body?
A personal who becomes ill after pathogens enter the body because they cannot fight off the pathogen
What is encased in a protein coating?
DNA or RNA is encased in a protein coating
The Pathogen
The Reservoir
- A reservoir is the principal habitat in which a pathogen lives, flourishes and is able to multiply. Common reservoirs for infectious agents include humans, animals or insects and the environment. Human reservoirs In humans, there are two forms of reservoir: acute clinical cases (in which someone is infected and is displaying signs and symptoms of the disease); and carrier…
The Portal of Exit
- The portal of exit is any route which enables a pathogen to leave the reservoir or host. In humans the key portals of exit are: 1. Alimentary – via vomiting, diarrhoea or biting 2. Genitourinary – via sexual transmission 3. Respiratory – through coughing, sneezing and talking 4. Skin – via skin lesions 5. Trans-placental – where transmission is from mother to foetus
The Mode of Transmission
- The two main ways that an infection can be transmittedfrom its reservoir to a susceptible host are via direct transmission or indirect transmission. Direct transmission tends to be instantaneous and occurs when there is direct contact with the infectious agent. Examples include tetanus, glandular fever, respiratory diseases and sexually transmitted diseases. Indirect transmission ca…
The Portal of Entry
- The portal of entry is the means by which an infection is able to enter a susceptible host. Portals of entry into the human body include: 1. Inhalation (via the respiratory tract) 2. Absorption (via mucous membranes such as the eyes) 3. Ingestion (via the gastrointestinal tract) 4. Inoculation (as the result of an inoculation injury) 5. Introduction (via the insertion of medical devices)
The Susceptible Host
- The last link in the chain of infection is the susceptible host. How susceptible any host will be, depends on a variety of factors: 1. Their age – and in particular if they are very young or very old 2. Whether there is any presence of malnutrition or dehydration 3. Whether there is any underlying chronic disease 4. If the host suffers from immobility 5. If they are taking any medication which …
How Can We Break The Chain of Infection?
- The healthcare environment can expose patients to infection risks that they may not encounter elsewhere. Understanding how infections become established, and how they are transmitted, is essential for effective infection prevention and control. There are opportunities to break or disrupt the chain at any link: though the rapid and accurate diagnosis of an infectious disease; the prom…