The Real Difference Between Bacteria And Viruses

If there's one thing we all know to avoid these days, it's a virus. As in coronavirus, of course... but we also don't want a stomach virus, or any other sort of contagious illness that will keep us laid up in bed while the rest of the world acts as if we've got the plague. But what about sickness due to bacteria? No one wants that, either — whether you're talking about an infected tooth or cut, or strep throat. Clearly, bacteria and viruses are both things that everyone hopes to avoid. But what's the difference?

To get an accurate answer to this question, Health Digest interviewed Mauricio Heilbron, M.D., trauma surgeon and vice chief of staff at St. Mary's Medical Center. "A bacterium is a life form — a one-celled organism that can survive in all sorts of environments," explained Heilbron, who goes by the nickname "Dr. Mo." Meanwhile, he said, "A virus is just a string of genetic material, surrounded by a little protective coat. It invades a normal cell, incorporates itself into the cell's genetics, and takes over." 

So basically, bacteria and viruses are like computers with very different operating systems. Both of them, unfortunately, can make us feel pretty awful!

These two operating systems attack our bodies using very different strategies. With bacteria, Heilbron said, "Many of them can cause disease, by producing toxins, cause inflammatory immune-mediated reactions... all sort of ways," he explained. "These things can 'live' on their own, spread via the bloodstream, the airways, stool, and urine, and are what we are treating when we prescribe antibiotics." A virus, however, "can make copies of itself, then cause the cell to explode and spread more of itself," Heilbron explained. "That destructive process can affect different cells — and organs — and in different fashion."

While you can treat a bacterial infection with an antibiotic, these medications won't do anything to help treat a virus, Heilbron added. The only medicine that can attack a virus is an antiviral — "of which there are comparatively few," he explained. Note that these are strategies aimed at eliminating the cause of the illness, "but much of the supportive treatment — fluids, anti-inflammatories, need for ICU/ventilator support — is the same," Heilbron said. If you're struggling to breathe, you'll get supplemental oxygen, whether it's a virus or a bacterial infection that's causing your respiratory symptoms. 

Ultimately, you can end up experiencing identical symptoms when you're sick with a virus one year, and it's a bacteria making you sick the next winter season. "[V]ery similar ailments [may have] a very different cause," Heilbron explained. "Sore throats, for example, can be caused by bacterial infections or viral infections, and so can pneumonias. Bacteria and viruses are simply how we get infected... you can't really compare them in terms of length of illness, severity, etc." But, once you know the cause, it can be easier for your doctor to narrow down the treatment options.

While the general public right now is on alert about coronavirus specifically, that doesn't mean that all viruses are necessarily more dangerous than all bacteria, Heilbron added. "The difference in experience depends on the bacteria or the virus, not if it's a bacterial or a viral infection." A virus can be a minor under-the-weather feeling, but it also can be life-threatening. "Think of how different AIDS is, compared to the flu. Or herpes. Or Ebola. Or COVID. All viral," noted Heilbron. As serious as these may be, specific diseases caused by bacteria are no picnic, either — and other ailments can be very minor. "Think about the people who get flesh-eating bacteria and have parts of their bodies lopped off, compared to an angry zit. Urinary tract infections. Tuberculosis. Gonorrhea. All bacterial," Heilbron continued.