What is a bacterial infection?
Bacterial infections are any illness or condition caused by bacterial growth or poisons (toxins). You can get sick from getting harmful bacteria in your skin, gut (GI tract), lungs, heart, brain, blood or anywhere else in your body.
Harmful bacteria from the environment, an infected person or animal, a bug bite or something contaminated (like food, water or surfaces) can cause infections. Bacteria that’s not normally harmful but that gets into a place in your body where it shouldn’t be can also cause infections.
What is bacteria?
Bacteria are living things with only a single cell that can reproduce quickly. There are millions of bacteria that live all around us — in soil or water and on surfaces in our homes and workplaces. There are even millions of bacteria that live on your skin and inside of your body.
Most bacteria aren’t harmful, and many are even helpful. They can help you digest food and kill off other harmful forms of bacteria that try to invade your body. But even the helpful ones can hurt you if they grow where they’re not supposed to.
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What’s the difference between a bacterial infection and viral infection?
Living, single-celled organisms that can reproduce on their own cause bacterial infections. Only a few types of bacteria cause illness in people.
An organism that’s not made up of cells causes viral infections. Viruses always need to infect humans or other living things to create more copies of itself.
Antibiotics can treat most bacterial infections, but only a few viral infections have medications that treat them.
What are the types of bacterial infections?
Bacteria can cause many types of infections, depending on how you’re exposed and what part of your body it infects. Some common types of bacterial infections include:
- Food poisoning (gastroenteritis).
- Some skin, ear or sinus infections.
- Some sexually transmitted infections (STIs).
- Bacterial pneumonia.
- Most urinary tract infections (UTIs).
What are some examples of bacterial infections?
Common bacterial infections include:
- Campylobacter and Salmonella infections, common types of food poisoning.
- Cellulitis, boils and impetigo, skin infections.
- Pneumococcal disease, including ear and sinus infections and some types of pneumonia.
- Lyme disease, a disease spread by ticks.
- Bacterial vaginosis, an overgrowth of bacteria in your vagin*.
- Chlamydia and gonorrhea, sexually transmitted infections.
- Strep throat, a bacterial infection common in children that causes a sore throat.
- C. diff, an infection in your intestines.
- E. coli, a common cause of urinary tract infection (UTI).
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Is a bacterial infection serious?
There are many bacterial infections that aren’t usually serious or can be treated easily with antibiotics. Impetigo and boils are examples. However, any bacterial infection that gets deep into your body, like in your blood, heart, lungs or brain, can be life-threatening.
How do bacterial infections spread?
Bacterial infections can spread through droplets or dust in the air, direct or indirect contact, a vector (like a tick or mosquito) or contaminated food or water (vehicular).
Airborne or droplet
You can get bacterial infections through the air from contaminated dust or droplets of water or mucus (like phlegm or snot). Legionnaires’ disease, pertussis (whooping cough), tuberculosis, meningococcal disease and strep throat spread this way.
Contact
You can get bacterial infections from direct contact with infected skin or mucous membranes, or from indirect contact with contaminated surfaces. Bacterial diseases you get by contact include skin infections and some sexually transmitted infections (STIs) like gonorrhea and chlamydia.
Vector
Infections you get from bugs (like mosquitos, ticks or fleas) are called vector-borne. You can get Rocky Mountain spotted fever, Lyme disease and shigellosis through vectors.
Vehicular
While it sounds like something you get from your car, “vehicular” usually means you get sick from water or food (the “vehicle” of transmission). You can get gut (gastrointestinal) infections from E. coli, Campylobacter and Salmonella bacteria in contaminated food or water.
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Who do bacterial diseases affect?
Anyone can get a bacterial disease, and most of us will at some point in our lives. You’re at higher risk for getting an infection if you have:
- Diabetes.
- A weakened immune system (due to HIV/AIDS, cancer, cancer treatments or immunosuppressive medications).
- An open wound.
- Had surgery recently.
How does a bacterial infection affect my body?
Bacteria can hurt your body either when they reproduce or by releasing poisons (toxins) that damage your cells. Infections that only affect the surface of your skin or mucous membranes (like your throat or intestines) aren’t usually serious, but sometimes, bacteria can spread in your body and cause life-threatening illnesses. If bacteria gets into your blood, it can cause sepsis, a reaction to the infection that causes organ damage, which is sometimes fatal.
