The 4 Types of Infection

If you’ve ever had a cold, Athlete’s Foot, or even COVID-19, you’ve had some kind of infection. Infections like these are spread by germs. Germs can enter the body through a cut in the skin or through the mucus membranes through your nose, mouth, and other less hardy skin-like areas. Some germs you even swallow! 

What Is Infection?

Infection occurs when germs enter the body and multiply, causing disease and illness. Different kinds of pathogens, a fancy term for germs, cause different types of sickness and disease. They come in four types – viruses, bacteria, fungus, and parasites. 

These pathogens get into your body through skin-to-skin contact, the transfer of body fluids, or contact with feces. You might catch a germ by consuming contaminated food or water, inhaling airborne particles or droplets, or touching something that another person carrying germs has also touched. 

Germs are things that cause illness, but not all viruses, bacteria, fungi, or parasites are germs. Many are beneficial, and some are fundamental to how your body works.

Your body reacts to a germ by increasing and activating white blood cells, specialized cells that fight infection. They release antibodies or consume germs, fighting the things that shouldn’t be inside your body. 

That’s why you run a fever — some immune processes work better at higher temperatures, and some germs don’t survive as well in the heat.

Infection can also result in chills, headache, rash, achy muscles and joints, and mucus overproduction — the typical runny nose, coughing, and wheezing. If the infection becomes especially severe, it causes sepsis, characterized by the following:

  • Signs and symptoms of infection – fever and so on
  • Body temperature lower or higher than normal
  • Mental decline – confusion, sleepiness, difficulty rousing
  • Extreme pain, discomfort, shortness of breath, or other illness

When seeking treatment for an infection, it helps if you are familiar with different types of infections and their symptoms. Here is an overview of each of the four infection types.

Family First ER has invested in a complete line of future-forward diagnostic technology to help our physicians visualize bone and soft tissue damage. Learn more here.

Viral Infections

A virus isn’t even a whole cell. It’s part of the inside of a cell and is made of proteins. You may be familiar with the representation of the SARS-CoV-2 virus that causes COVID – the ball with spikes sticking out all over. 

Viruses come in many shapes, but all of them infiltrate the cells of the body and kill them or turn the cellular machinery over to create more virus particles.

When new virus particles are released from the cell, they infect yet more cells. If this happens to too many cells and the body doesn’t shut down the virus or viral production, you will get sick.

As a rule, viruses cannot live long outside of a host cell. They may only last minutes or hours, if that, on a dry surface. 

A virus can infect almost any part of your body. The type of virus or illness is usually named after that body part:

  • Encephalitis or meningitis – brain
  • Common cold – rhinovirus (nose)
  • Pharyngitis – vocal cords
  • Gingivostimatitis – mouth
  • Parotitis – lymph glands
  • Myelitis – heart
  • Gastroenteritis – stomach and intestines
  • Pancreatitis – pancreas

Viruses can infect your eyes, skin, or lungs. Many sexually transmitted diseases (STDs) are caused by a virus.

Viruses are treated mainly by allowing the body to fight them off. Anti-viral medications are still uncommon. Healthcare providers give you medicine to manage the symptoms and wait for the self-limiting viral infection to end. 

Vaccinations prevent many viral diseases, including:

  • Chickenpox
  • Mumps 
  • Measles 
  • Tetanus 
  • H. Influenzae Type B (HiB)
  • Pertussis (Whooping Cough)

Antibiotics are not effective against viruses. Taking antibiotics for viral illnesses can create the conditions for antibiotic-resistant bacteria and do nothing for your sickness.

Bacterial Infections

Bacteria are single-celled organisms that contain everything they need to live. They live in, on, and around the human body and almost everything else. Because they are self-sustaining, they can live for days or weeks on surfaces. Fortunately, relatively few bacteria are pathogenic (germs).

Good bacteria help your gut metabolize food, protect you from other illnesses, and rarely cause problems. Sometimes, though, bacteria, especially in high numbers, can create issues like body odor or disrupt the balance of the body’s normal flora (normal balance of bacteria). Then an overgrowth of one bacteria type can make you sick.

Some bacteria can cause serious illness, like:

  • Cholera 
  • Diphtheria
  • Dysentery 
  • Bubonic plague
  • Tuberculosis 
  • Typhus 

Bacteria can cause illnesses like strep throat, urinary tract infections, rashes, and meningitis. Some bacteria kill body cells and tissues as they rapidly multiply; others produce toxins that can paralyze or destroy cells or trigger a toxic immune response.

Your body fights bacterial infection by developing fever, redness, and pain at the wound site and elevating the temperature at the site.

Antibiotics are the first-line defense against bacterial infection. Most of the time, you take antibiotics orally (by mouth). Common antibiotics are penicillin, sulfa, tetracycline, and ciprofloxacin. For more immediate impact for severe infections, antibiotics may be given by IV.

Always take all the antibiotics prescribed. Stopping because you feel better lets the stronger bacteria live and become resistant to that antibiotic, making it useless.

Fungal Infections

Fungus is a single or multi-celled entity similar to bacteria. They live in and on the body without causing a problem unless you are immune-compromised or have a weakened immune system. For example, people with AIDS might develop fungal pneumonia because a fungus the lungs can usually handle overgrows and impairs breathing. 

Sometimes people on long-term antibiotics develop fungal infections because the bacteria that normally control the fungus have been killed by the antibiotic.

Fungi (plural of fungus) are spread by spores, which they use to reproduce. Athlete’s Foot is an example of fungal infection. Fungal infections are treated with anti-fungals like fluconazole or nystatin.

While ER visits are usually unplanned, there are ways to alleviate the stress and anxiety that accompanies an emergency. Here is what to expect during a visit to the ER.

Parasitic Infections

Many parasites that cause human infection are single-celled entities called protozoa. They thrive in moisture and usually spread disease through water, either because you swallow it or it enters through your eyes or ears.

A parasite is a form of symbiont in which the symbiosis is damaging to the host. Common parasitic infections include yeast infections (Candidiasis), Giardiasis (caused by the parasite Giardia Lamblia), malaria, and Chagas Disease (caused by trypanosomes). Other parasites are hookworm, tapeworms, flatworms, and roundworms. 

Ticks, lice, fleas, and mice are also parasites. They cause infection by burrowing under the skin.

Parasites can cause skin disease or intestinal illnesses like diarrhea or nausea. People with weakened immune systems may develop serious infections that spread to the major organs. 

Treatment begins with oral rehydration in cases of severe intestinal upset. Metronidazole (Flagyl) is the most commonly used broad-spectrum anti-parasitic. IV Quinine is used to treat malaria.

Most people with parasites have a mild, self-limiting illness.

Now You Know…

Now you know that infections can be caused by different types of germs – viruses, bacteria, fungi, and parasites. Each one responds to different kinds of treatment, and many are mild and self-limiting. 

Sometimes the illness becomes severe enough you need to see a healthcare professional or who can diagnose you and prescribe the right kind of medication.

In extreme cases, you may need to come to the emergency room. Contact us today to learn more about our emergency services for infectious diseases.