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Also indexed as: Bacterial Infection
Infection is the result of invasion of the body by microorganisms, including bacteria,
viruses, or fungi.
Not all microorganisms cause infections in the body, and exposure to a disease-causing
microorganism does not always result in symptoms. The immune system plays a large role in
determining the body’s ability to fight off infection.
Some examples of infection are common cold/sore
throat, influenza,
cough, recurrent ear infections, urinary tract infection,
yeast infection, athlete’s foot, cold sores, HIV, shingles, and
parasites.
What are the symptoms of infection?
Symptoms of infection include localized warmth, redness, swelling, discharge, foul-smelling
odor, and pain to the touch. In more serious cases, symptoms
may also include fever, chills, nausea, vomiting,
diarrhea, and fatigue.
Medical treatments
Over the counter agents available to treat minor bacterial skin infections include
benzalkonium chloride (Zephiran®), neosporin (Myciguent®), bacitracin
(Baciguent®), and combination antibiotic formulas (Neosporin®, Polysporin®).
Fungal skin infections may be treated with clotrimazole (Lotrimin AF®), miconazole
(Micatin®), and terbinafine (Lamisil®). Drugs
used to treat vaginal yeast infections include clotrimazole (Gyne-Lotrimin®,
Mycelex®), miconazole (Monistat®), and butoconazole (Femstat 3®). Individuals
with infections that do not respond to over the counter medications should seek medical
advice.
Prescription strength topical, oral, and intravenous
antibiotic medicines are reserved for more serious bacterial infections; these include cephalosporins, such as cephalexin (Keflex®),
cefaclor (Ceclor®), and cefazolin (Ancef®); lincosamides, such as lincomycin
(Lincocin®) and clindamycin (Cleocin®);
macrolides, such as
erythromycin (Ery-Tab®), clarithromycin
(Biaxin®), and azithromycin (Zithromax®); penicillins, such as
penicillin VK (Veetids®), amoxicillin
(Amoxil®), and dicloxacillin (Dynapen®); and
sulfonamides, such as sulfasoxazole (Gantrisin
Pediatric®) and sulfamethoxazole
(Gantanol®, Septra®, Bactrim®). Antiviral
drugs are available to treat infections caused by herpes simplex and human immunodeficiency
virus (HIV). Numerous drugs are available to treat topical and systemic infections caused by
fungus and yeast.
Surgical treatment is recommended in some cases to remove diseased tissue, prevent the
spread of infection, or drain pus from an infected area.
Dietary changes that may be helpful
Nutrition is a major contributor to the functioning of the immune system, which in turn
influences whether or not the body is resistant to infection. Specifically, it makes sense to
restrict sugar, because sugar interferes with the
ability of white blood cells to destroy bacteria.1 Alcohol also interferes with a
wide variety of immune defenses,2 and excessive dietary fat reduces natural killer cell activity.3
However, there is no research investigating whether reducing sugar, alcohol, or fat intake
decreases the risk of infection or improves healing.
Allergy, including food allergy, has been suggested
to predispose people to recurrent infection,4 and many doctors consider allergy
treatment for people with recurrent infections. The links between allergy and ear infections,5 6 urinary tract infections in children,7 and yeast vaginitis in women8 9 have
been documented.
Lifestyle changes that may be helpful
Stress can depress the immune system, thus
increasing the body’s susceptibility to infection. Coping effectively with stress is
important.10 Exercise increases natural killer cell activity, which may also help
prevent infections.11
Nutritional supplements that may be helpful
Nutrients useful for maintaining healthy immune function are also applicable for preventing
infections. Vitamin A plays an important role in immune
system function and helps mucous membranes, including those in the lungs, resist invasion by
microorganisms.12 However, most research shows that while vitamin A supplementation
helps people prevent or treat infections in developing countries where deficiencies are
common,13 little to no positive effect, and even slight adverse effects,
have resulted from giving vitamin A supplements to people in countries where most people
consume adequate amounts of vitamin A.14 15 16 17
18 19 20 Moreover, vitamin A supplementation during
infections appears beneficial only in certain diseases. An analysis of trials revealed that
vitamin A reduces mortality from measles and diarrhea, but not from pneumonia, in children living in
developing countries.21 A double-blind trial for vitamin A supplementation in
Tanzanian children with pneumonia confirmed its lack of effectiveness for this
condition.22 In general, parents in the developed world should not give
vitamin A supplements to children unless there is a reason to believe vitamin A deficiency is
likely, such as the presence of a condition causing
malabsorption (e.g., celiac disease). However,
the American Academy of Pediatrics recommends that all children with measles should be given
high-dose vitamin A for several days.
Vitamin C has antiviral activity, and may help prevent
viral infections23 or, in the case of the
common cold, reduce the severity and duration of an infection.24 Most studies
on the common cold used 1 to 4 grams of vitamin C per day.
Lactobacillus acidophilus (the friendly
bacteria found in yogurt) produces acids that kill
invading bacteria.25 The effective amount of acidophilus depends on the strain
used, as well as the concentration of viable organisms. These and other friendly bacteria
known as probiotics inhibit the growth of potentially
infectious organisms (pathogens) by producing acids, hydrogen peroxide, and natural antibiotics called bacteriocins and microcins, by utilizing
nutrients needed by pathogens, by occupying attachment sites on the gut wall that would
otherwise be available to pathogens, and by stimulating immune attacks on pathogens.
Infections that have been successfully prevented or treated with friendly bacteria include
infectious diarrhea,
vaginitis, and urinary tract infections.26
Marginal deficiencies of zinc result in impairments of immune function.27 Supplementation with
50 mg of zinc three times per day for 30 days has been shown to increase immune function in
healthy people.28 However, such large amounts of zinc can potentially cause adverse
effects. Some doctors recommend lower amounts of supplemental zinc for people experiencing
recurrent infections, such as 25 mg per day for adults and even lower amounts for children
(depending on body weight). Zinc lozenges have been found helpful in some studies for the common cold. Zinc has not been studied as prevention or
treatment for other types of infection.
A multiple vitamin-mineral formula helped elderly
people avoid infections in one double-blind trial, but not in another.29
30 In a double-blind study of middle-aged and elderly diabetics, supplementation with a
multiple vitamin and mineral preparation for one year reduced the risk of infection by more
than 80%, compared with a placebo.31 In another double-blind trial, supplements of
100 mcg per day of selenium and 20 mg per day of zinc, with or without additional
vitamin C, vitamin E, and beta-carotene, reduced infections in elderly people, though
vitamins without minerals had no effect.32 That study suggests that trace minerals
may be the most important components of a multiple vitamin and mineral formula for preventing
infections.
Premature infants with very low birth weight have an increased susceptibility to
infections. In a double-blind trial, premature infants were given either selenium supplements (5–7 mcg per 2.2 pounds of body weight)
or placebo. Those receiving the selenium supplements had fewer hospital-acquired
infections.33
Athletes who undergo intensive training
or participate in endurance races (such as a marathon) are at increased risk of developing
infections. In a double-blind study, marathon runners received either glutamine (5 grams immediately after the race and 5 grams again
two hours later) or a placebo. Compared with the placebo, supplementation with L-glutamine
reduced the incidence of infections over the next seven days by 62%.34
Are there any side effects or interactions?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful
The main herbs for infection can be broken down into three basic categories: those that
support a person’s immune system in the
fight against microbes, those that directly attack microbes, and those that do both. These
categories are summarized in the table below. Note that this table does not include herbs that
are largely used for parasitic infections of the
intestines.
| Mechanism of Action |
Examples |
| Immune supportive |
American ginseng, andrographis, Asian
ginseng, astragalus, coriolus, eleuthero, ligustrum, maitake, picrorhiza, reishi, schisandra, shiitake |
| Antimicrobial |
Chaparral,
eucalyptus, garlic, green
tea, lemon balm (antiviral), lomatium, myrrh, olive leaf, onion, oregano, pau d’arco
(antifungal), rosemary,
sage, sandalwood, St. John’s wort, tea tree
oil, thyme, usnea |
| Both immune supportive and antimicrobial |
Barberry,
echinacea, elderberry, goldenseal, licorice, Oregon grape, osha, wild
indigo |
Are there any side effects or interactions?
Refer to the individual herb for information about any side effects or interactions.
References
1. Sanchez A, Reeser JL, Lau HS, et al. Role of sugars in human
neutrophilic phagocytosis. Am J Clin Nutr 1973;26:1180–4.
2. Ahmed FE. Toxicological effects of ethanol on human health. Crit
Rev Toxicol 1995;25:347–67.
3. Kubena KS, McMurray DN. Nutrition and the immune system: A review of
nutrient-nutrient interactions. J Am Diet Assoc 1996;96:1156–64.
4. Horesh AJ. Allergy and infection VII. Support from the literature.
J Asthma Res 1968;6:3–55 [review].
5. Pang LQ. The importance of allergy in otolaryngology. Clin
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6. Nsouli TM, Nsouli SM, Linde RE, et al. Role of food allergy in serous
otitis media. Ann Allergy 1994;73:215–9.
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8. Crandall, M. Allergic predisposition and recurrent vulvovaginal
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zinc and immune function. Fed Proc 1986;45:1474–9.
28. Duchateau J, Delespesse G, Vereecke P. Influence of oral zinc
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29. Chandra RK. Effect of vitamin and trace-element supplementation on
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Vitam Nutr Res 1993;63:11–6.
31. Barringer TA, Kirk JK, Santaniello AC, et al. Effect of a
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32. Girodon F, Lombard M, Galan P, et al. Effect of micronutrient
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Copyright © 2004 Healthnotes, Inc. All rights reserved.
www.healthnotes.com
Learn more about Healthnotes, the company.
Learn more about the authors of Healthnotes.
The information presented in Healthnotes is for informational
purposes only. It is based on scientific studies (human, animal, or in vitro),
clinical experience, or traditional usage as cited in each article. The results reported may
not necessarily occur in all individuals. For many of the conditions discussed, treatment with
prescription or over-the-counter medication is also available. Consult your doctor,
practitioner, and/or pharmacist for any health problem and before using any supplements or
before making any changes in prescribed medications. Information expires March 2005.
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