Health. Care. | An Educational Blog

Germ theory, the idea that infection is caused by microscopic organisms unseen to the naked eye, is only a few hundred years old. This theory focuses on three main components.

1. The reservoir: The person, animal, or surface that carries the infection.
2. The mode of transmission: Via direct contact, a droplet of liquid, airborne, a vector (such as an insect), or a vehicle (food or surface)
3. The susceptible host: A person and his/her ports of entry (nose, mouth, incision, medical device, wound)

But the paths from the reservoir to the susceptible host seem infinite. To narrow down the steps needed to prove this relationship between contaminated rooms and infected patients, researchers have proposed routes of transmission that could account for a relationship. Here are two proposals, both of which demonstrate the critical role played by surfaces in the transmission of pathogens.

In our previous posts about DALYs and QALYs, we have defined the terms and presented how the healthcare field calculates these two measures of disease burden. In today's post, we will narrow our view to just hospital-associated infections and their disease burden. After reading this post, you should have a more detailed picture of the impact HAIs have on American lives.

We've covered Candida auris in this blog before. Not only has it been one of the pathogens of concern cited by the Centers for Disease Control and Prevention, this fungus also infected record numbers of inpatients during the COVID-19 pandemic. This disease-causing pathogen has hit headlines once again, this time brining attention to troubling increases in rates and resistance. What can hospitals - and patients - do to avoid this dangerous hospital-associated infection?

Last week's post introduced the work of Louis Pasteur, the father of microbiology. It was not long after Pasteur proposed that microorganisms were to blame for food spoilage that someone would make the leap that infection could, too, also be caused by microorganisms. That man (who would become a great scientific rival to Pasteur) came to be known as the founder of modern bacteriology.

There is really no way to overstate the importance of Girolamo Fracastoro's bold proposal about the roots of infection. His idea that infections were caused by "seeds," living things unseen to the naked eye, was followed by deductions that included the spread of contagion, incubation periods, the organs affected by particular infectious agents, the vulnerable age for a particular disease, the idea that a survivor of an infection is protected against future infections, the ability of a disease to pass from mother to child through nursing, and many other valuable observations. His genius, while respected and supported, was not definitively proven until over 100 years later, with the advent of the microscope.

Civilization picked up speed after the discovery of agriculture and animal husbandry, allowing for longer lifespans, healthier people, and lots of population growth. Unfortunately, with population growth comes denser living quarters, enabling contagious diseases to spread more quickly. As humankind spread across the globe in waves of migrations, so did epidemics of unfathomable destruction.

We take for granted the knowledge that infection is caused by microscopic organisms. But the road to this scientific truth has been long and winding, and medical professionals have taken some pretty odd detours along the way. Hindsight being 20/20, we can examine this path and see the seeds - or germs - of germ theory as we know it today.

A study demonstrated that regular soap has the same impact as antibacterial soap at killing bacterial during hand washing. Today we'll explore this study, the chemical being evaluated, and what these results mean to the debate about whether or not antibacterial soaps are helpful.

There is a good chance that you have Staph - Staphylococcus aureus - on your body right now. In fact, it is estimated that 25-30% of us carry Staph on our skin or in our nose all the time. But a quarter of us are not sick, suffering from the symptoms of a Staph infection. What's the deal? It comes down to colonization vs. infection.

There are may different pathogens that cause HAIs. Researchers have studied which of these infectious agents tend to cause infections, how those pathogens are transmitted, and which protocols lead to less contamination. Today we'll explore which pathogens cause hospital-acquired infections, which are the most common, and how long can these pathogens survive on surfaces where they can lead to cross-contamination. Think of it as the three P's: Pathogen, Prevalence, and Persistence.