How are bacterial infections prevented?

Definition

Bacterial infections are infections that are caused by microorganisms called
bacteria. Common bacterial infections include
urinary tract
infection (UTI), strep throat, tuberculosis
(TB), Helicobacter pylori infection, and
methicillin-resistant Staphylococcus aureus (MRSA).

Types of Bacterial Infection

UTI is a bacterial infection of one or more parts of the urinary system. Most UTIs originate in the bladder or urethra, but they also can begin in the kidneys or ureters. Strep throat is an infection of the throat that is caused by the group A Streptococcus (GAS) bacterium. TB is a bacterial infection that affects the lungs. H. pylori is a bacterium that affects the intestinal tract. It causes chronic gastritis and duodenal and gastric ulcers, and it may contribute to the development of gastric cancer. MRSA is a staph infection that has become resistant to the antibiotics that are normally used to treat staph infections.

Prevention

UTIs most commonly occur when bacteria that normally live in the intestine enter the urethra. Other sources of bacteria that can cause UTIs are sexual intercourse, urinary catheters, and obstruction, such as kidney stones or prostate problems.

No vaccine exists for the prevention of UTI. However, one can take the following measures to reduce the risk for UTIs: Drink a minimum of eight glasses of water per day, urinate as soon as possible after intercourse, take showers instead of tub baths, wipe from front to back after urination or bowel movement, avoid spermicidal foams or jellies, and avoid feminine hygiene sprays or douches.

Strep throat is spread through droplets in the air when an infected person sneezes or coughs or by contact with infected objects. As with UTIs, no vaccine exists for the prevention of strep throat. One should take the following measures to reduce the risk of contracting strep throat: Wash hands frequently, especially before preparing or eating food; when possible, avoid contact with people who have strep infections; and avoid sharing personal items such as drinking glasses, eating utensils, and toothbrushes.

TB is spread through droplets in the air when an infected person sneezes or coughs. Although a vaccine has been developed for the prevention of TB, it is not commonly used in the United States. The TB vaccine, which is also known as the Bacillus Calmette-Guérin (BCG) vaccine, does not always protect against TB and could cause a false-positive result in people who are later tested for TB.

Even without the use of the BCG vaccine, there are still some things one can do to prevent the spread of TB. One method is to treat TB-infected persons before their disease becomes active. This involves regular testing of people who may be at risk. For persons who test positive for TB infection, certain medications can be prescribed by doctors to help prevent active disease. Other methods of preventing the spread of TB include covering the nose and mouth with a tissue when coughing or sneezing, opening windows to ventilate rooms if the weather permits, avoiding the workplace when sick, wearing a mask around others, and avoiding close contact with family members for the first few weeks of treatment.

It is not known how H. pylori infection is contracted, so
there are no specific recommendations for prevention. However, to prevent
complications of H. pylori infection, persons with symptoms of
gastritis or gastric or duodenal ulcers are frequently
tested for H. pylori and are treated if found to be infected.

MRSA can be acquired in hospitals and other healthcare settings, and in specific communities, such asnursing homes. MRSA infection is spread through contact with a contaminated person or object. In the health care setting, MRSA is frequently prevented through isolation of infected persons and through practicing standard precautions, such as handwashing and wearing protective gloves and clothing.

There are several measures that one can take to prevent the spread of MRSA in the community setting. These measures include covering wounds with clean, dry bandages until they have healed; frequent handwashing; not sharing personal items, such as towels, wash cloths, or razors; periodic cleaning of frequently touched surfaces with disinfecting wipes; and washing bed linens in hot water.

Impact

According to the National Institute of Diabetes and Digestive and Kidney
Diseases, UTIs account for more than 8 million doctor visits each year in the
United States. UTI is more common in women, and one in five women will get a UTI
at least once during her lifetime. The Centers for Disease Control and Prevention
(CDC) reports that between 9,000 and 11,500 cases of invasive
GAS disease occur each year in the United States, resulting in 1,000 to 1,800
deaths annually.

The World
Health Organization estimates that one-third of the world’s
population is infected with TB at any given time, and that 5 to 10 percent of
infected persons will develop active TB in the future. In 2009, about 1.7 million
people died from TB.

The CDC estimates that approximately two-thirds of the world population is infected with the H. pylori bacterium, and that between 2 and 20 percent of those persons infected will develop ulcers. Furthermore, CDC statistics show that in 2005, more than 94,000 people developed a serious MRSA infection and more than 18,000 people died during a hospital stay related to these infections.

Bibliography

Brachman, Philip S., and Elias Abrutyn, eds. Bacterial Infections of Humans: Epidemiology and Control. 4th ed. New York: Springer, 2009.

Brogden, K., et al. Virulence Mechanisms of Bacterial Pathogens. 4th ed. Washington, D.C.: ASM Press, 2007.

Centers for Disease Control and Prevention. “ Helicobacter pylori: Fact Sheet for Health Care Providers.” Available at http://www.cdc.gov/ulcer/keytocure.htm.

Mayo Foundation for Medical Education and Research. “Tuberculosis.” Available at http://www.mayoclinic.com/health/tuberculosis/DS00372.

_______. “Urinary Tract Infection.” Available at http://www.mayoclinic.com/health/urinary-tract-infection/DS00286.

“Strep Throat.” Available at http://www.webmd.com/oral-health/tc/strep-throat-topic-overview.