There are diverse types of living organisms residing on the planet Earth. Some may be visible to the naked human eye, while others can only be seen under a microscope.
While we human beings always try to live in harmony with the world, certain microbes can cause the human race to suffer from diseases and illnesses. This has prompted scientists and biologists to study those microbes in more detail.
Their studies have made humans more resistant to diseases and were able to increase the life span of humans.
Among all the microbes that have been known to cause immense damage to humans, there are two types: Viruses and bacteria.
Key Takeaways
- Viruses are submicroscopic infectious agents composed of genetic material (DNA or RNA) enclosed in a protein coat, requiring a host cell to reproduce and carry out its life cycle.
- Bacteria are single-celled microorganisms with a simple cellular structure, capable of reproducing independently and performing various metabolic functions necessary for survival.
- The main difference between viruses and bacteria is their size, complexity, and reproductive capabilities, with viruses being smaller, simpler, and reliant on host cells, while bacteria are larger, more complex, and able to reproduce independently.
Virus vs Bacteria
Bacteria are living organisms that can exist within or outside of a body. They are capable of procreating independently of the host organism. Bacterial infections can be effectively treated by antibiotics. While viruses require a host to survive and replicate. Viruses cannot be treated with antibiotics.

A virus first needs to have access to the hostโs body. This may be possible through the respiratory tract or open wounds.
After the virus has gotten inside the hostโs body, only then can it become the source of spreading the disease.
Bacteria, on the other hand, live freely in the environment and also inside us. They multiply quickly when they are given the right conditions to thrive.
Some bacteria cause infections, but most of them do not pose any threat. There are multiple differences between the virus and the bacteria, which will be shown in the comparison table below.
Comparison Table
Parameter of Comparison | Virus | Bacteria |
---|---|---|
Need for Host | The virus cannot survive without a host. | Bacteria can survive without a host. |
Size | Viruses are smaller than bacteria. | Bacteria are more significant than viruses. |
Chance of disease | All types of viruses can cause disease. | Not all types of bacteria can cause disease. |
Severity of treatment | Viruses are more complex to treat than bacteria. | Bacterial infections are easier to treat |
Examples | AIDS, Common colds. | Strep throat, Tuberculosis, E. coli. |
What is Virus?
Viruses are small microscopic organisms that are only able to survive and thrive using living things as host bodies. A virus is made up of genetic material, either RNA or DNA, surrounded by a coat of protein.
Sometimes, this coat is further surrounded by a spiky coat called an envelope. Viruses are considered to be the smallest out of all microbes.
Viruses have been the cause of diseases like Ebola which was spread in West Africa in 2014, and also swine flu disease in 2009.
A virus works by attaching itself to a healthy cell and then using those cells to replicate itself and spread the disease. When a virus enters your body, you may not get aware of it at first because it does not suddenly make you sick.
A virus takes a few days or weeks as the incubation period before the symptoms start to show in the body. During this time, the virus is preparing to attack with full force.
A viral infection cannot be treated with antibiotics. You need anti-viral medicines to treat them.
Some viruses can also be treated with vaccines. But generally, you need to have a robust immune system as well for the treatment to work and fight the virus off.

What is Bacteria?
Bacteria are one-celled organisms that can survive in different environments. They may be present in the ocean, soil, and inside humans.
Not all bacteria are harmful. There are some good bacteria too. For example, we need bacteria to turn milk into yoghurt and some healthy bacteria to help digest the food in our stomachs.
Since bacteria are single-celled, they are termed prokaryotes. They have a simple structure that lacks a nucleus, and the DNA floats freely like a thread or in circular pieces.
There are four basic shapes of bacteria: circular shaped or cocci, cylindrical-shaped, capsule-based or bacilli and spiral-shaped. Sometimes, their names reflect their shapes.
For example, the milk-curding bacteria is called Lactobacillus acidophilus.
Bacteria multiply by a process called binary fission. In this process, the bacterium creates a copy of itself and grows larger.
The bacterial cell then splits, and there are two identical cells form.
Bacterial infections can be treated with antibiotics. But new studies have suggested that bacteria are developing resistance to these medicines.
Let our immune systems fight these infections first on their own before taking some medicines for treatment.

Main Differences Between Virus and Bacteria
Five distinct features differentiate between the virus and the bacteria.
- A Virus needs a host body to survive and thrive, while bacteria do not need a host body to survive.
- Viruses are smaller in size than bacteria. The size of the bacterium is larger than the virus.
- All types of viruses can cause disease, while all bacteria do not cause disease. Some bacteria are healthy.
- Viral infections are harder to treat than bacteria, whereas bacterial infections are easier to treat.
- AIDS, Common colds are examples of viral infections. Strep throat, Tuberculosis, and E. coli are examples of bacterial infections.

- https://www.livescience.com/53272-what-is-a-virus.html
- https://science.howstuffworks.com/life/cellular-microscopic/virus-human.htm
Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.