What Is an Infectious Disease? Examples of Basic Types

, Staff Writer
Updated March 26, 2020
Scientists doing research in laboratory
    Scientists doing research in laboratory
    Morsa Images / DigitalVision / Getty Images

Have you heard the term “infectious disease” on the news? If you are confused as to what an infectious disease is or how it is spread, you have come to the right place. Learn how infectious diseases are caused, transmitted and even cured. You’ll also get information on how to prevent infectious diseases in your body.

What Are Infectious Diseases?

It happens every year! You get a headache, fever and cough. Next thing you know, you have the flu. The flu (influenza) is a common infectious disease infecting more than 40 million people each year. Then, there are the epidemics and pandemics like Ebola and coronavirus that pop up. So, what is an infectious disease?

Infectious diseases are a class of diseases and their symptoms, like fever and cough, caused by tiny organisms. They get into our bodies where they don’t belong and make us sick. While some are just annoying, like the common cold, others like pneumonia can lead to death.

Learn about the basic examples of infectious diseases and the organisms that cause them.


Basic Examples of Infectious Diseases

Infectious diseases are no fun. Some of the most common infectious diseases come from bacteria, viruses, fungi and parasites. Now, find out what each one is and as well as some common types of each.

Bacterial Infections

Bacteria are little microbes found all over the world. Not only do they live on you and in you, but they can be found in the air, water and soil. Most of the time, bacteria are harmless or even helpful. However, certain strains can wreak havoc on our bodies.

This happens when “bad” bacteria get inside an area of a body where they don’t belong, like from eating undercooked meat or through a cut in your skin. These bacteria include streptococcus pneumoniae, staphylococcus aureus and escherichia coli.

Common bacterial infections include:

  • Pneumonia
  • Bacterial meningitis
  • Tuberculosis
  • Food poisoning (E. coli)
  • UTI (urinary tract infections)
  • Salmonella infections
  • Skin infections like MRSA (methicillin-resistant Staphylococcus aureus)

While these infections cause a range of symptoms from fever and diarrhea to serious skin infections, most bacterial infections can be treated with antibiotics. However, some strains of infections like MRSA are becoming resistant to antibiotics, so doctors try other various treatments.


Viral Infections

Little microbe hijackers, viruses have genetic code inside a protein shell. They use that genetic code to hijack your cells to make more viruses to attack or modify some part of your body. With millions of viruses floating around, they can be quite dangerous.

However, contracting a virus means you need to come into contact with someone who is already sick or infected. You can get exposed through the air after a sneeze or cough. It’s also transmitted by touching their hands or a surface they’ve left the virus on. A few newsworthy viruses include H1N1, COVID-19, Ebola, Zika virus and human immunodeficiency virus (HIV).

Examples of viral infections include:

  • Cold
  • Flu
  • Polio
  • Stomach flu
  • Hepatitis C
  • Coronavirus

Treating someone infected by a virus can be harder than treating a bacterial infection. While there are antiviral medications, most of the time, you can only treat the symptoms while your immune system does its thing. Antibiotics are typically ineffective against viral infections.

Some serious viral infections can lead to further complications, like bacterial infections. For viruses, prevention through frequent and proper handwashing is the best medicine.


Fungal Infections

Eww, fungus. Fungal infections are a common woe of many athletes and people all around the globe. Fungi spread through spores and are found all over the natural world. Once these little invaders infect the body, they can be difficult to kill.

You can get fungal infections from inhaling spores or by getting them on your skin. They like to take hold of individuals who have a weakened immune system.

Common fungal infections include:

  • Thrush
  • Candidiasis
  • Ringworm
  • Athlete’s foot
  • Valley fever

Unlike bacterial and viral infections that can cause fevers and coughs, fungal infections typically cause a rash. Treatment includes the application of an antifungal medication, like a cream or ointment.

Parasitic Infections

Now it’s time to talk about parasites. These little moochers use a host to survive. Unknown to the host, they can grow and multiply, invading their system. Parasites could be transmitted by mosquitoes by bites or through the mouth from dirty hands. Parasitic infections come from protozoa, helminths and ectoparasites like:

  • Malaria
  • Trichomoniasis
  • Giardia
  • Tapeworms
  • Ticks

The treatment for parasite infections is as varied as the different types of parasites but can include antibiotics, creams and specialized medications.


Preventing Infectious Diseases

Half of the battle against infectious diseases is prevention. For example, you may get a vaccine against infectious diseases like polio or the flu. Keeping your body and area clean can also be important in fighting infectious diseases. However, since most infectious diseases are transferred from dirty hands, correct handwashing is pivotal to staying healthy.

The Basics on Infectious Diseases

Infectious diseases are no joke. While some are common, others can be killers. Knowing what they are and how you might prevent them is key to staying healthy. Now that you’ve explored examples of infectious diseases, you might be interested in examples of zoonotic diseases and how they spread.