Bacteria and viruses are different types of microorganisms. Not all of them cause illness and disease, but bacterial and viral pathogens have the potential to do so.
This article describes the differences between bacterial and viral infections, and gives examples of each.
We also outline the different treatment options for bacterial and viral infections and provide tips on how to prevent infections in general.
Bacterial vs. viral infections
Pathogens are micrcoorganisms that cause illness and disease.
Bacteria, viruses, and fungi are different types of microorganisms.
Pathogens are microorganisms that have the potential to cause illness or disease.
Bacterial pathogens cause bacterial infections, whereas viral pathogens cause viral infections.
Sometimes, both bacteria and viruses can cause illness. Examples include pneumonia and meningitis.
What is a bacterial infection?
Bacteria are living organisms that have just one cell. There are many different species of bacteria. Some live inside the human body and carry out functions, such as:
helping people to digest food
getting rid of cells that could cause disease
Less than 1% of bacterial species can cause bacterial infections. Such infections occur when the bacteria enter the body and invade the body’s immune system, where they quickly multiply and produce harmful toxins.
Examples of bacterial infections
We outline some common types of bacterial infection below.
Streptococcus or strep is a group of bacteria. There are two main types: alpha (α)-hemolytic streptococci, and beta (β)-hemolytic streptococci.
Alpha-hemolytic streptococci includes the bacterial species Streptococcus pneumoniae (S. pneumoniae), as well as Viridans group streptococci.
S. pneumoniae usually exist on the skin and inside the throat. This bacterial species can cause minor infections, such as sinus infections and middle ear infections. More severe infections include:
bacteremia, which is a bacterial infection of the blood
Viridans group streptococci
Viridans group streptococci most commonly exist in the mouth, gut, and genital region. Severe infections can occur if the bacteria enter other parts of the body.
A Viridans group streptococci infection that enters the bloodstream can infect the inner lining of the heart. The medical term for this is endocarditis. It is a serious condition that requires prompt medical treatment.
There are two types of Beta-hemolytic streptococci: Group A and Group B streptococci.
Group A strep
An infection by group A strep, or Streptococcus pyogenes, can be invasive or non-invasive. Invasive infections are those that spread to the bloodstream.
The most common non-invasive Group A strep infections include:
Invasive Group A strep infections are much rarer. They may lead to the following conditions:
the flesh-eating disease necrotizing fasciitis
Group B strep
Group B strep, such as Streptococcus agalactiae usually live harmlessly inside the digestive system and female genital tract.
Group B strep most commonly affects newborns. This is because the bacteria can pass from mother to fetus in the womb. According to one article, most people develop a natural immunity to Group B strep as they get older.
A newborn who has a Group B strep infection may display the following signs and symptoms:
floppiness and unresponsiveness
unusually low or high body temperature
unusually slow or fast heart rate
Without treatment, a Group B Strep infection may lead to serious conditions, such as meningitis and pneumonia.
There are more than 30 types of Staphylococcus, or staph, bacteria. Most staph infections are due to the species Staphylococcus aureus (S. aureus). This bacteria lives on the skin or inside the nose and can enter the body through an open wound.
Staph bacteria can cause various types of infections, including:
toxic shock syndrome