Can You Catch the Same Cold Twice?: Microbial Myths 3

Sept. 14, 2022

Can you microwave your sponge to sanitize it? Does chicken noodle soup cure everything? Fact or Fiction? Microbial Myths 3.

Microbial Myths 3

At ASM Microbe 2022, Dr. Michael Schmidt joined us in the ASM Studio to continue the tradition of demystifying some common microbial myths. The conversation was hosted in front of a live, and wonderfully enthusiastic audience, and the session quickly became standing room only, as Schmidt wittingly dispelled common misconceptions and confirmed the validity of a few [not-so-far-fetched] home remedies (e.g., chicken noodle soup and old sour cream).

In this summary of Microbial Myths 3, we cover factors that should be considered when attempting to "sanitize" your sponge in the microwave, whether alcoholic drinks can be safely shared without spreading microbes, when is the best time to apply deodarant and does old sour cream .    

You Can Microwave Your Sponge to “Sanitize” It.

Verdict: It Depends.

First a reminder: definitions are critical. Across the globe, government agencies, like the U.S. Environmental Protection Agency (EPA) operationally define terms like disinfect, sanitize, clean and sterilize. For example, products used to kill viruses and bacteria on  surfaces  are registered as antimicrobial pesticides. This goes back to a law abbreviated FIFRA, which stands for the Federal Insecticide, Fungicide, and Rodenticide Act 7 U.S.C. §136 et seq. (1996), stating that sanitizers and disinfectants are 2 types of antimicrobial pesticides.

Now back to the story… when a sponge is placed in the microwave, the mode of action is treating a wet porous object with moist heat. If a membrane perturbant, such as dish soap, is also present, there is added potential of supplementing the intended killing action.

However, while, the internet is replete with instructions that it takes only 2 minutes to kill 100% of bacteria on your sponge, effectiveness ultimately depends on the starting concentration (or initial load) of bacteria, water content of the sponge, power of the microwave and the supplemental effect of the sponge.

Drinks Containing Alcohol (Beer, Wine, Mixed) Don’t Spread Germs, So They Are Safe to Share.

Verdict: Proceed With Caution.

In this case, the type of microbe, concentration of alcohol and time on target are all part of the equation. Beer can range in absolute alcohol concentrations from 0, to as high as double digit percentages. This is also true for wine and mixed drinks, which depend on mixer volume, whether any component of the drink has antimicrobial activity (e.g., phosphoric acid in Diet Coke) and the concentration of EtOH. The length of time that a given microbe is exposed to a particular concentration of alcohol will directly impact the inactivation potential, with lower concentrations of alcohol generally requiring a longer time on target.

Ultimately, Schmidt's adivce is to proceed with caution. "Know who you are sharing with, and decide whether you are willing and able to swap spit," he said.

You Should Apply Deodorant in the Morning. 

Verdict: False 

Its important to consider whether one's goal is to reduce body odor (deodorant), control the deposition of liquid (antiperspirant) or both. Research indicates that the most effective time of day to apply deodorant is at night before going to bed, and this is especially important when it comes to antiperspirants. 
Why? Body temperature is lower at night, which typically means dryer underarms. In short, both deodorant and/or antiperspirant will have a better chance of working on dryer skin.

You Catch the Same Cold Twice.

Verdict: True

In a NY times article in 2018, Richard Klasco, M.D. offered a definitive response, based on data, that one can, indeed, catch the same cold twice, depending on the strength of their immune response.

Most of what we know about immunity to cold viruses is based on ethically studies performed in the late 1950s and early ’60s in which medical students or military recruits—whose participation may have been less than fully voluntary—were intentionally infected with cold viruses.

In one landmark study from the late 50s, over 1,000 stalwarts were inoculated with the infectious nasal secretions from a patient with an active cold. After becoming infected and being allowed to recover, the subjects were challenged again with the same virus to study their response. In a later, particularly rigorous study from 1963, 50 subjects were confined to a dormitory for an entire month to assess their ability to withstand reinfection with the same cold virus.

The results of these studies showed that for many people, infection with a cold virus can indeed provide effective immunity against subsequent exposure to that particular virus. More than half of the study participants made sufficient amounts of antibodies and were protected. Those who had a less robust antibody response, however, were not protected and came down with a cold after being reinfected.

Microbial Myths 3: True or False? 

Interested in skipping to a particular myth to hear the verdict? Here is a list of timestamps to help you navigate the video:
  • 0:29 You can microwave your sponge to “sanitize” it.
  • 3:11 Drinks containing alcohol (beer, wine, mixed) don’t spread germs, so they are safe to share.
  • 5:07 Infants need to be bathed every day.
  • 8:18 You should apply deodorant in the morning. 
  • 9:12 Teething causes fever in babies.
  • 10:35 You catch the same cold twice. Or you can catch the same cold back-to-back. 
  • 12:42 Replacing your toothbrush after you’ve been sick will keep you from getting re-infected.
  • 12:55 Chicken noodle soup cures…everything.
  • 14:20 Letting a wound dry out speeds healing.
  • 15:28 You can fix chapped hands with old sour cream.
  • 17:06 Green snot means a bacterial infection, and yellow, or clear, snot a viral one.
  • 19:15 Chewing gum stays in your stomach for 7 years.
  • 19:33 Long-COVID is contagious.
  • 19:58 The flu shot can give you the flu.
  • 20:06 Energy-efficient washing machines are a preferred clothes washing method.
  • 21:01 Bacterial cells outnumber your own by 10:1.

Author: Ashley Hagen, M.S.

Ashley Hagen, M.S.
Ashley Hagen, M.S. is the Scientific and Digital Editor for the American Society for Microbiology and host of ASM's Microbial Minutes.