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Host
Host
Simply put, a host is anyone who is not immune to the infection. A person's ability to resist infection is very individual. There are people who become clinically symptomatic and ill when an infecting pathogen enters their body. At the same time there are people who are immune to or are able to resist the infection. Another person exposed to the same infection may not show any signs or symptoms of having the infection, yet pass it on to others and are known as "carriers".
Infection Risk
Infection Risk
When considering the amount of risk relating to infections, there are three things that influence that risk.
When considering the amount of risk relating to infections, there are three things that influence that risk.
- Virulence: How easy is it for the pathogen to infect a new host?
Some pathogens have a high virulence which means they can infect a person easily. Others have a low virulence, making it harder for them to infect a person. Virulence depends on many factors including the general health of the host, previous infections and the design of the pathogen.
- Survivability: How well does the pathogen survive outside of its host?
Some viruses are quite hearty and will live for a long time outside of the body on a surface. Other viruses have a very short life outside the body. The virus family that cause the common cold (and COVID-19) have a high ability to survive outside the body. The HIV virus has a very low ability to survive, meaning it is nearly impossible to pick it up from a contaminated surface.
- Concentration: How much of the pathogen is in a typical sample?
The amount of a pathogen in a sample of blood or fluid changes how likely it is to get that pathogen into your body. Imagine a bowl of M&M's and you are asked to use one hand to scoop out as many green M&M's as you can. If the bowl has an equal or lesser number of green M&M's compared to the rest of the other colours, it will be harder to get that many green M&M's. However, if the bowl is 80% green M&M's, it will be a lot easier.
Watch the following video to learn more about why these terms are important when considering infections that have impacted our lives.
Watch the following video to learn more about why these terms are important when considering infections that have impacted our lives.
What is Coronavirus?
What is Coronavirus?
For almost a decade, scientists chased the source of a deadly new virus through China's tallest mountains and most isolated caverns. They finally found it in the bats of Shitou Cave. The virus in question was a coronavirus that caused an epidemic of severe acute respiratory syndrome, or SARS, in 2003. So what exactly is a coronavirus, and how does it spread? Elizabeth Cox explains. [Directed by Anton Bogaty, narrated by Bethany Cutmore-Scott, music by Jarrett Farkas].
For almost a decade, scientists chased the source of a deadly new virus through China's tallest mountains and most isolated caverns. They finally found it in the bats of Shitou Cave. The virus in question was a coronavirus that caused an epidemic of severe acute respiratory syndrome, or SARS, in 2003. So what exactly is a coronavirus, and how does it spread? Elizabeth Cox explains. [Directed by Anton Bogaty, narrated by Bethany Cutmore-Scott, music by Jarrett Farkas].
Breaking the Chain
Breaking the Chain
Transmission of an infectious agent does not occur if any of the links in the chain of transmission are "broken". Transmission may be interrupted when:
the agent is eliminated, inactivated or cannot exit the reservoir
portals of exit are eliminated through safe practices
transmission between objects or people does not occur due to barriers and/or safe practices
portals of entry are protected
hosts are not susceptible
In many cases, proper personal hygiene and sanitary conditions are the best ways to prevent or stop the spread of pathogens. Vaccinations are close behind, and for some pathogens are the only means of keeping people safe from them.
Two important terms to consider when discussing breaking the chain are sanitizing and disinfecting.
Sanitize means to lower the number of pathogens on surfaces or objects to a safer level.
Disinfect means killing the pathogens on surfaces or objects.
Accessing Reliable Information
Accessing Reliable Information
Visit the website for your regional Public Health Unit and look for valuable resources related to breaking the chain of infection. The following link from the York Region Public Health Unit outlines ways you can Break the Chain of Infection for respiratory illness ranging from the common cold to more severe illness.
Do a search for your Public Health Unit for a topic that may interest you (i.e. Handwashing, masks, PPE) and you will find reliable, up-to-date information.
See if you can find the answer to the following commonly asked question:
Does antibacterial soap clean my hands better than regular soap?
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