What causes bacterial diseases?

Bacterial diseases are caused by harmful bacteria (pathogenic bacteria). The vast majority of bacteria do not cause disease, and many bacteria are actually helpful and even necessary for good health. Bacterial diseases occur when pathogenic bacteria get into an area of the body that is normally sterile, such as the bladder, or when they crowd out the helpful bacteria in places such as the intestines, vagina or mouth. Less common, bacterial infections can occur when healthy bacteria multiply uncontrollably. 

Various ways pathogenic bacteria can enter the body

Pathogenic bacteria can enter the body through a variety of means including:

  • Contamination of bites, cuts, rashes, abrasions and other breaks in the skin, gums and tissues

  • Eating  contaminated food

  • Getting bitten by an infected insect

  • Having sexual contact with an infected person

  • Inhaling contaminated air-borne droplets into the nose and lungs

  • Kissing an infected person

  • Sharing needles for tattooing or drug use

  • Through the eyes, ears or urethra

  • Touching infected feces or body fluids, and not washing your hands before eating or touching your mouth, eyes or nose

Once bacteria enter the body, a healthy immune system will recognize the bacteria as foreign invaders and try to kill or stop the bacteria from reproducing. However, even in a healthy person, the body is not always able to stop the bacteria from multiplying and spreading. As the harmful bacteria reproduce, they can crowd out healthy bacteria and microorganisms and emit toxins that damage the cells of the body.

What are the risk factors for bacterial diseases?

Bacterial diseases can occur in any age group or population, but a number of factors increase the risk of developing bacterial diseases. Not all people with risk factors will get bacterial diseases. Risk factors for bacterial diseases include:

  • Being an infant, child or older adult

  • Eating eggs or meats that are raw or undercooked

  • Eating expired foods, or eating leftovers that have been stored for more than two to three days

  • Having a genetic predisposition to bacterial infection

  • Having a compromised immune system due to an immunodeficiency disorder, HIV/AIDS, diabetes, cancer or cancer treatment, kidney disease, or from taking steroid medications   

  • Having a chronic disease

  • Malnutrition

  • Not washing your hands frequently, especially after using the bathroom, touching pet feces, handling reptiles, or touching raw foods or foods contaminated with bacteria

  • Significant exposure to a person with a bacterial disease

Reducing your risk of bacterial diseases

You can lower your risk of developing or transmitting bacterial diseases by:

  • Avoiding contact with a person who has a bacterial disease or its symptoms, such as fever, vomiting or diarrhea

  • Covering your mouth and nose with a tissue when sneezing or coughing, then washing your hands

  • Defrosting foods in the refrigerator or microwave, not on the counter

  • Refrigerating leftovers right away and eating them within two to three days unless they have been frozen

  • Eating a healthy diet that is high in whole grains, fruits and vegetables and contains adequate low-fat protein and low-fat dairy products or other calcium sources

  • Getting enough rest and minimizing stress

  • Getting recommended vaccines for bacterial diseases, such as meningitis, pneumonia, tetanus and rabies

  • Seeking regular medical care and following your treatment plan for a chronic disease

  • Throwing out expired food or perishable food that has been sitting at room temperature for two hours or longer

  • Using antibacterial products to clean surfaces, such as computer keyboards, telephones and sinks

  • Washing your hands after using the bathroom and after contact with pet feces, reptiles, dirty diapers, raw foods, and people who are ill

  • Washing plates, utensils, and cutting boards that have been exposed to raw meats or poultry in hot soapy water

  • Wearing long pants and sleeves, and using insect repellant when in tall grass or wooded areas


What are bacterial diseases?

Bacterial diseases include any type of illness caused by bacteria. Bacteria are a type of microorganism, which are tiny forms of life that can only be seen with a microscope. Other types of microorganisms include viruses, some fungi, and some parasites.

... Read more about bacterial diseasesintroduction


What are the symptoms of bacterial diseases?

Symptoms of bacterial diseases vary depending on the type of bacterial infection, the area of the body that is infected, and other factors, such as the patient’s age and health history. The symptoms of bacterial diseases can also resemble symptoms of other diseases, such as colitis, influenza, and viral infections. The classic symptom of a bacterial infection is a fever, although not all people... Read more about bacterial diseasessymptoms


How are bacterial diseases treated?

Bacterial diseases are treated with antibiotics. Antibiotics work by killing the harmful bacteria or by stopping them from reproducing and spreading. Different types of antibiotics are effective for treating specific types of bacteria. Antibiotics may be given orally, intravenously, or by intramuscular injection, depending on the type a... Read more about bacterial diseasestreatments

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Jul 30, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Infections and Contagious Diseases, Cold and Flu

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