Difference Between Bacterial and Viral Infection (With Table)

CDC (Centers for Disease Control and Prevention) has reported about 15.5 million cases of infections and 3.7 million emergency cases every year. Infections occur due to the entry of harmful organisms into the body. Infections are classified into various types depending on the organism involved. These types of infections are viral infections, bacterial infections, fungal infections, parasitic infections, prion infections, etc. The 2 most common types of infections are bacterial and viral infections.

Bacterial vs Viral Infection

The main difference between bacterial and viral infection is that bacterial infection is caused due to harmful bacteria, whereas viral infection is caused due to harmful viruses. While bacterial infection persists in the body for 2 weeks, the viral infection persists in the body for 1 week. While antibiotics can treat bacterial infections, viral infections can be treated by antiviral medicines and drugs.

When harmful bacteria enter the body, it causes bacterial infection. These infections result from contact (direct or indirect) with the bacteria. The transmission of these infections takes place through feces, food, and sharing of personal items. These infections also pass from mother to child. Examples of bacterial infections include strep throat, UTI (urinary tract infections), bacterial vaginosis, etc.

A viral infection occurs when a harmful virus intrudes into the body. The transmission of these infections takes place through direct touch, sexual contact, saliva, and sharing of needles. Sometimes, insects also act as vectors and result in the transmission of diseases. Intake of contaminated food also results in transmission. Viral infections tend to be highly contagious.

Comparison Table Between Bacterial and Viral Infection

Parameters of Comparison

Bacterial Infection

Viral Infection

Causing Agent

Bacterial infections are the result of the entry of harmful bacteria into the body.

Viral infections are the result of the entry of harmful viruses into the body.

Transmission Methods

Bacterial infections spread from one person to another through direct contact, vectors, airborne methods, droplets, and vehicular means.

Viral infections spread through direct contact, saliva, sharing of needles, vectors, and contaminated food.


The symptoms of bacterial infection are:HeadacheSwollen lymph nodesFeverDiarrheaSorenessFever and Chills

The symptoms of viral infections are:High FeverAbdominal PainVomiting and nauseaLoss of sensationImpaired bowel functionSleepiness and Confusion


The tests for detecting bacterial infections are:Urine testSwab sample testCBC (complete blood count) testImaging tests such as X-ray

The methods of detecting viral infections are:Direct detection methods such as Microscopy and StainingVirus isolation methods such as PCRSerology methods such as antibodies.


The antibiotics for treating bacterial infections include ciprofloxacin, amoxicillin, and erythromycin.

Antiviral drugs and medicines are used for the treatment of viral infections.

What is Bacterial Infection?

Shaped like balls, spirals, and rolls, bacteria refers to living creatures with a single cell. Various kinds of bacteria will have varying effects on the body. The intrusion of bacteria into the body, thereby leading to chemical reactions and various imbalances in the body, is known as bacterial infection. When a bacterium enters the body, it first multiplies itself and then triggers the destruction in our body. The intrusion of bacteria into the body can even take place through the skin. 

The diseases caused due to bacteria may range from minor ones such as ear infections to serious ones such as meningitis. The common infections include Salmonella, Tuberculosis, etc. Salmonella, much like food poisoning, is caused due to intake of uncooked poultry. The bacteria present in the GI of various poultry animals enter the body and thereby show symptoms such as diarrhea, vomiting, abdominal pain, stomach upset, etc. Tuberculosis is a lung infection caused due to the bacteria Mycobacterium tuberculosis. 

Clostridium difficile refers to the good and harmless bacteria residing in our gastrointestinal tracts. If a person has a weak immune system or uses antibiotics, these bacteria get multiplied in numbers, leading to infections in the gastrointestinal tract. The symptoms of these infections are constant diarrhea and inflammation of the colon. Various bacteria lead to various diseases, which in turn have varying symptoms.

What is Viral Infection?

Viruses refer to organisms that have a protein coat surrounded by RNA/DNA as their genetic material. These organisms can’t reproduce all by themselves. They are dependent on their host for their food and survival. However, it’s still unsure whether these organisms are alive or not. As they reproduce and take energy from the host’s body, some scientists consider them to be alive. On the contrary, as they lack cella and the ability to reproduce by themselves, some scientists consider them to be dead.

Viruses are both harmful and helpful. Viral infections occur due to the intrusion of a harmful virus into the human body. On entering the host’s body, they transfer their genetic material into the cell body of the host. As a result, they keep multiplying themselves, thereby leading to the hijacking of the cell’s internal machinery. Further, these multiplied viruses lead to their multiplication in the host’s body, thereby harming the concerned body part. 

Most common viral infections affecting the respiratory tract include Rhinovirus, Seasonal influenza, RSV (Respiratory Syncytial Virus), etc. The most common viral infections infecting the skin include Molluscum contagiosum, VZV (Varicella-zoster virus), etc. The most common viral infections affecting the stomach include Hepatitis A, Norovirus, Rotavirus, etc.

Main Differences Between Bacterial and Viral Infection

  1. Bacterial infection is not always contagious. However, viral infections are most contagious. 
  2. While antibiotics help treat bacterial infections, viral infections can’t be treated with antibiotics. Antibiotics have no effect on viruses and are thus, valueless.
  3. While the bacterial infection is localized, the viral infection affects the whole body. 
  4. In bacterial infections, the symptoms last in the body for up to 2 weeks. But, in viral infections, the symptoms last in the body for no less than 1 week. 
  5. Examples of bacterial infections include whooping cough, ear infection, strep throat, UTIs. On the other hand, the examples of viral infections include flu, common cold, bronchitis, HIV/AIDS, coughs, chickenpox, etc. 


Infections, irrespective of their type, weaken our immune system significantly. Thus, one should stay away from these organisms and their resulting diseases. One can do this by maintaining proper hygiene, taking vaccinations on time, and not sharing the use of personal items. Moreover, practicing safe sex and regular usage of sprays and insect repellents is also essential. One should also stay away from wild animals. With proper hygiene and cleanliness, one can avoid these infections. Moreover, on noticing the symptoms, one should contact the doctor at the earliest, thereby taking the prescribed medicines and taking proper care of themselves.


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