Let’s
first take a look at how many of the popular disinfectants work. Cleaners like Lysol
have different types of salts in them that kill germs by disrupting important
protein interactions, which causes the pathogen to stop functioning normally.
These salts can also work by breaking up the membrane that surrounds bacteria
and some viruses, essentially breaking open the pathogen and causing everything
inside it to leak out. In both of these cases, the germs stop growing or are killed altogether.
Alcohol-based
hand sanitizers work in a similar manner. At concentrations of at least 60%,
ethyl alcohol (or ethanol) is effective at killing some viruses, including
influenza viruses. Ethanol works by changing the shape of proteins, and
therefore interferes with their ability to properly interact with other
proteins. Ethanol can also disrupt membranes.
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| Image of Influenza virus from the CDC highlighting proteins on the outer surface that help the virus infect cells, and the viral genome located inside. |
While
killing off the germs that can make us sick sounds like a good way to stay
healthy, the problem with using disinfectants and sanitizers to do this is that
these products kill nearly all of the microbes in our environment. While there
are many microbes that make us sick, there are also many that we need to help
keep us healthy. If we kill those microbes off too, then we may put ourselves
at risk for developing other health problems.
On and
within our bodies live millions and millions of good microbes that do things
from helping us digest food, to helping keep bad microbes out of our bodies.
These good microbes encompass the population known as the microbiome. The
microbiome populations shift depending on the location of the body. For
example, we have good bacteria that live on our skin, the population of which
differs from the population of good bacteria that live in our digestive tracts. There is increasing interest in exploring the
functions of the different microbiome populations, and many studies are showing
that the microbiome has important roles in keeping us healthy. For example, it
is thought that irregularities in the gut microbiome population may have a role
in some inflammatory bowel diseases like Crohn’s disease and ulcerative
colitis. It is possible that killing off the beneficial microbes in and on our
bodies counteracts any good effect from killing off germs.
Keeping our good microbes around is only part of the story. According to the CDC, we are currently on the brink of a public health crisis due to the increasing numbers of microbes that are becoming resistant to common antibiotics. Due to our overuse and misuse of antibiotics, we have created strains of bacteria that are no longer susceptible, or able to be killed, by standard treatments. As bacteria populations are constantly exposed to antibiotics, many of those bacteria will be killed because they are sensitive to the antibiotic, but there will be some that are naturally able to withstand the actions of the antibiotic. Eventually, the population of bacteria that was initially a mix of sensitive and resistant will transition to a population of bacteria that is completely resistant, as all of the susceptible bacteria are killed off. What is the impact on us? In 2013, the CDC reported that at least 2 million people in the United States become infected with antibiotic-resistant bacteria, and that at least 23,000 of these people die from their infections.
Perhaps
the most well-known case is MRSA, or methicillin-resistant Staphylococcus aureus. Staph bacteria are common and normally
cause minor skin infections; however, MRSA has been highlighted in the media
several times over recent years due to the outbreaks of invasive infections it
has caused due to its resistance to standard antibiotics. MRSA is but one example
of the bacterial strains that develop resistance to antibiotics due to constant
exposure to them.
As we
continue the cycle of overuse and misuse of antibiotics, we eventually will
find ourselves at a point where no antibiotics will be effective against
bacterial pathogens. Many public health experts suspect that point is near. There
is reason to believe that constant use of disinfectants will eventually lead to
the development of germs that are resistant to those disinfectants, just as we
see happening with bacteria and antibiotics.
So how
do we keep ourselves healthy without potentially setting ourselves up for other
health problems later? We can start by
limiting our use of disinfectants, and go back to simpler, tried-and-true
methods of preventing the spread of communicable diseases. Despite the
popularity of disinfectants and hand sanitizers, the CDC still maintains that
hand-washing is one of the best ways to avoid spreading and catching viral and
bacterial infections from others. Wash your hands before you eat, and avoid
touching your hands to your eyes and nose.
If you are sick, do your best to sneeze or cough into the crook of your
elbow (i.e., do the “Dracula sneeze”) rather than into your hands, and wash
your hands frequently to avoid spreading your germs to others.
Of course, use soap that does not contain antimicrobial additives, like triclosan, to avoid encouraging the development of strains resistant to this compound. Soap is a potent killer of germs all by itself - it does not need supplemental antibiotics. While some companies are moving away from including triclosan, it is still present in many products, so be sure to check your labels.
Disinfectants
have their place; they’re good for cleaning up food preparation areas that have
come into contact with raw meat, for example. And, in times when you’re without
clean water and soap, hand sanitizer can be a great tool for keeping your hands
clean. But as with most things in life, these items should be used with care
and arguably in balance with other washing methods in order to avoid creating
greater problems down the line.
Contributed by: Kelly Hallstrom
Follow Kelly on Twitter.
CDC
Threat Report on Drug-Resistant Bacteria:
CDC and
hand washing:
