Key facts
- Bacteria are single cells that can survive on their own, inside or outside the body.
- Viruses cause infections by entering and multiplying inside the host's healthy cells.
- It can be difficult to know what causes an infection, because viral and bacterial infections can cause similar symptoms.
- Antibiotics won't work for viral infections. Misusing antibiotics to treat viral infections contributes to the problem of antibiotic resistance.
- Antibiotics won't cure viral infections.
How are bacteria different from viruses?
Bacteria and viruses are too tiny to see with the naked eye. They can cause similar symptoms and are often spread in the same way, but are different in most other ways.
Bacteria are single cells that can survive on their own, inside or outside the body. Most bacteria aren't harmful. In fact, you have many harmless and helpful bacteria on your skin and inside your body, especially in the gut to help digest food.
Viruses are smaller and are not cells. Unlike bacteria, they need a host such as a human or animal to multiply. Viruses cause infections by entering and multiplying inside the body's healthy cells.
How are bacterial infections different from viral infections?
It can be difficult to know what causes an infection, because viral and bacterial infections can cause similar symptoms. Your doctor may need a sample of your urine, stool or blood, or a swab from your nose or throat to see what sort of infection you have.
If you have symptoms on an infection, it is important to know if it is caused by bacteria or viruses, because the treatments differ.
Examples of bacterial infections include whooping cough, strep throat, ear infection and urinary tract infection (UTI).
Examples of viral infections include the common cold and flu, most coughs and bronchitis, chickenpox, monkeypox, COVID-19 and HIV/AIDS.
What treatment will I receive for bacterial and viral infections?
Treating a bacterial infection
Doctors usually treat bacterial infections with antibiotics. It's important to match the antibiotic with the specific type of bacterial infection you have. The right antibiotic will kill bacteria or stop them multiplying.
Antibiotic resistance is a growing problem in Australia and the world. It is caused, in part, by overuse of antibiotics in humans, animals and the environment. This is one of the reasons why your doctor will only prescribe antibiotics when they are confident that the benefits of treatment are greater than the risks.
Treating a viral infection
Antibiotics aren't effective against viral infections. If you have a viral infection, your doctor may recommend one or more of the following treatments:
- rest at home to allow your immune system to fight the virus
- managing symptoms, such as warm drinks or chicken soup to soothe your throat and stay hydrated
- paracetamol to relieve fever
- stopping viral reproduction using antiviral medicines, such as medicines for HIV/AIDS and cold sores
- preventing infection in the first place, such as vaccines for flu and hepatitis
FAQs
Bacteria are single cells that can survive on their own, inside or outside the body. Viruses cause infections by entering and multiplying inside the host's healthy cells. It can be difficult to know what causes an infection, because viral and bacterial infections can cause similar symptoms.
What are the 3 main differences between bacteria and viruses? ›
Difference Between Virus And Bacteria
| Bacteria | Virus |
|---|
| Bacteria are large in size. The size ranges from 900 to 1000nm | Smaller in size. The size ranges from 30 to 50nm |
| Non-Living/Living |
| They are living organisms | They can replicate only within the host cell |
| Mode of Reproduction |
18 more rowsBacteria are living organisms, and Viruses are not. Bacteria are unicellular, and Viruses are consider cell-less. Bacteria reproduce through fission, while viruses reproduce by invading a host cell, taking it over, and causing it to make copies of itself.
How do you know the difference between a viral and bacterial throat infection? ›
Knowing whether your sore throat is viral or bacterial is usually determined by symptoms. Viral sore throats usually consist of a cough, swelling in the throat, and runny nose whereas bacterial sore throats are typically accompanied with nausea and vomiting, stomach ache, and there is no cough.
How to know if a viral or bacterial cough? ›
In addition to lab tests, sputum or mucus from a cough can be visually examined to determine whether bronchitis is viral, bacterial, or both. Clear or white mucus often indicates a viral infection, while yellow or green mucus may suggest a bacterial infection.
What is the difference between a viral and bacterial skin infection? ›
Unlike bacterial infections, viral infections cannot be treated with antibiotics. Common viral skin infections include chickenpox, measles, shingles, herpes simplex, warts, molluscum contagiosum, and hand, foot, and mouth disease.
What feature may be found in viruses but never in bacteria? ›
Viruses can have a diverse set of nucleic acids as their genetic material. Viruses can have a genome of single-stranded RNA, single-stranded DNA, double-stranded RNA, and double-stranded DNA. In contrast, bacteria never have RNA genomes, and always have double-stranded DNA genomes.
Can you take antibiotics for a virus? ›
Antibiotics work by destroying bacterial cell membranes and bacterial replication. Since viruses are not cells, they do not have cell membranes, so antibiotics are ineffective against them.
How do all viruses are similar to bacteria? ›
Viruses and bacteria have a number of characteristics in common. Both are microscopic. Although both vary in size, they are too small to be visible to the naked eye. Both carry genetic material and both lack membrane-bound organelles.
Can you tell the difference between a viral and bacterial chest infection? ›
The symptoms of viral and bacterial chest infections are similar but the colour of any mucus coughed up may indicate the cause; white or clear mucus usually indicates a viral infection whereas green or yellow mucus suggests that the infection is bacterial.
Viral tonsillitis typically goes away on its own in about one week. Bacterial tonsillitis takes about 10 days to run its course, but you'll likely need antibiotics to reduce your risk of complications.
Can you pass on a bacterial infection? ›
Many bacterial infections are contagious, meaning that they can be transmitted from person to person. There are many ways this can occur, including: close contact with a person who has a bacterial infection, including touching and kissing.
What are five common symptoms of a viral infection? ›
Symptoms of a viral infection depend on where you're infected, but some common ones include:
- Flu-like symptoms: fever, head and body aches, fatigue.
- Upper respiratory symptoms: sore throat, cough, sneezing.
- Digestive symptoms: nausea, vomiting, diarrhea.
- Skin conditions: rashes, sores, blisters, warts.
You should see your doctor if you have:
- a persistent fever or chills.
- severe headache or neck stiffness.
- eye redness and crusting (pus)
- persistent ear pain or wetness (discharge)
- persistent facial pain and runny nose.
- difficulty breathing.
- a persistent cough, or coughing up blood or pus.
Your doctor may prescribe antibiotics if the symptoms are severe and include high fever along with nasal drainage and a productive cough. Antibiotics may also be necessary if you feel better after a few days and then your symptoms return or if the infection lasts more than a week.
Is a fever bacterial or viral? ›
Although high degrees of fever occur in viral and bacterial infections, high fever may predict serious bacterial infection.
