The right antibiotic at the right time has been the difference between life and death during innumerable bacterial infections since they came into wide use during World War II. Fantastic as these drugs can be against bacterial infections though, they don’t help get rid of viral infections at all.
If you stock some antibiotics against a time when they are hard to get (as many preppers do), you absolutely would not want to waste them on conditions for which they weren’t helpful. But how could you tell the difference? Not being a physician myself (and therefore not giving you medical advice), I hit up the medical literature for suggestions on how to recognize when an infection is likely to be viral rather than bacterial.
What’s the difference between viral and bacterial, anyway?
Bacteria are independent living cells. They are different from our cells — much more metabolically capable, actually, in many cases. That means the bacteria have metabolic pathways we don’t use. Antibiotics exploit these differences by poisoning pathways bacteria need, but our cells don’t have.
Viruses are not complete living cells; they’re much simpler particles that parasitize our cells and trick our cells into making more viruses. Viruses don’t use the metabolic pathways the antibiotics poison, so viral diseases aren’t affected by antibiotics.
Upper respiratory infections are usually viral
Colds and flu of course make up most of the upper respiratory infections, and these are viral in origin. Unless there’s some reason to particularly suspect a bacterium, these wouldn’t be good targets for antibiotics. When is it a sinusitis or ear infection or pneumonia that needs antibiotics? Here are some tips: (1)
- Symptoms last longer than a normal cold or flu. (For kids, more than 10-14 days; a little less for adults)
- Fever is more than low grade. Colds may only a degree or two of fever if that. Flu has more; and also has more body aches. The higher the fever the more likely it’s bacterial. I get suspicious when the fever’s over 102 F.
- If the fever gets worse a few days into the illness, it may be a sign that a viral infection has allowed a bacterial infection to join it.
- Ear pain is more likely from bacterial infection.
Pneumonia is more likely viral, but not overwhelmingly so
Among children at least, pneumonia was completely viral in about half the cases, and viral with some later bacterial complication in 25%. Only 15% started out bacterial and the rest were undetermined. (3) Adult cases were even more heavily weighted toward viral causes. (4)
Pneumonia is also more likely to be viral if the temperature is not very elevated (2), and if the pneumonia included a cough (4).
Urinary tract infections are more likely bacterial
Unlike most of the other infections in this piece, urinary tract infections aren’t usually caught directly from another sick person. They’re more likely to come from bacteria on the surface of the body that migrate up into the bladder, and maybe higher. Burning pain on urination is the biggest clue of these problems. Small children, women, and elderly men are most often affected.
When one of these shows up, it’s not very likely viral. The bacterium E. coli is the most common agent. Other bacteria are also common causes. Viruses can cause this problem, but it’s a minority of cases.
If it’s viral, antibiotics are worse than just wasteful
We’ve hit this topic before (here and here, for example) but it bears repeating: Taking antibiotics when you don’t need them does more harm than just wasting antibiotics. Here are some reasons not to take antibiotics for viral problems, or taking the wrong kind or amount of antibiotic:
- Development of antibiotic-resistant strains of bacteria.
- Destruction of helpful microbes. This most often expresses as diarrhea.
- Other side effects peculiar to the antibiotic used.
