Germ is a term that is comfortable and familiar to most of us, so it is a great starting point to talk about how infection spreads. Germs are another way of saying microbes, or microorganisms, which are single-celled organisms like bacteria or viruses.
The main difference between bacteria and viruses is that bacteria are living cells that can live inside or outside a body, while viruses are a non-living collection of molecules that need a host to survive.
Germs are so small that they are invisible to the naked eye. Scientists who study germs, called microbiologists, need powerful microscopes to examine microorganisms like the COVID-19 virus.
When germs cause infection in the body, they are called pathogens. Germs are all around us so we are exposed to them constantly, but the vast majority of bacteria are non-pathogens, meaning that they are harmless to the body. On the other hand, pathogens are a real and constant danger to humans—especially those with weaker immune systems due to health concerns or age. We can follow infection control practices, such as washing our hands regularly and effectively, to reduce the number of pathogens we are exposed to.
Watch this the following video to understand more about microorganisms and the first infection control practices.
Video: Micro-Biology: Crash Course History of Science #24 (12:11):
Click here for a video transcript in .docx format: Video Transcript
After watching the video above, read the description of the following observed phenomena and then answer the “why?” question to identify the associated scientific discovery for each one.
When you are determining whether you are dealing with an infectious germ, you will need to look for clues. Use the information you learned from the video of microbes and how they affect your body to point to what type of process may be affecting the client and where it may have come from—is it something that originated in their body or did it come from an outside source? Proceed to the next page to review a case study that will allow you to practice this kind of investigation.