Are cold and flu caused by bacteria or viruses? Do antibiotics kill viral infections?
Well, no doubt, bacteria and viruses cause diseases but they do this in different ways. Viruses have different structures and replicate in a different way than bacteria. Therefore, antibiotics which work by targeting the growth machinery in bacteria (not viruses) to kill or inhibit those particular bacteria- are ineffective against viruses.
When you think about it structurally, it makes sense that an antibiotic could not work to kill a virus since both have a completely different set of replicating “machinery”.
Examples of common illnesses caused by viruses:
- Most sore throats
- Most coughs, colds and runny noses
- Some eye or ear infections
- Flu (Influenza)
Examples of illnesses caused by bacteria:
- Urinary tract infections
- Bacterial meningitis
- Bacterial pneumonia
- Whooping cough (pertussis)
- Many skin infections
- Some ear or eye infections
- Some sinus infections, but usually these are viral
Most viral illnesses do not need special medication and are “self-limiting”, meaning your own immune system will kick in and fight off the illness with adequate rest and plenty of fluids. However, this can take time. For example, a cough and cold can last from 7 to 10 days. Symptoms – like fever or aches and pains – MAY BE TREATED with proper doses of pain and fever relievers like acetaminophen or ibuprofen, or as directed by your doctor.
Most viral illnesses do not need special medication and are “self-limiting”, meaning your own immune system will kick in and fight off the illness with adequate rest and plenty of fluids.
If SYMPTOMS PERSISTS FOR MORE THAN 10 DAYS, be sure to contact your doctor.
Sometimes, in complicated or prolonged viral infections, bacteria may invade as well, and cause what is known as a “secondary bacterial infection”. In these cases, your doctor may prescribe an antibiotic, if one is needed, to kill the specific invading bacteria, but the antibiotic is not prescribed for the virus.