How an infectious disease is treated depends on the microbe that caused it and sometimes on the age and medical condition of the person affected. Certain diseases are not treated at all, but are allowed to run their course, with the immune system doing its job alone. Some diseases, such as the common cold, are treated only to relieve the symptoms. Others, such as strep throat, are treated to destroy the offending microbe as well as to relieve symptoms.
The last century saw an explosion in our knowledge about how microbes work and in our methods of treating infectious diseases. For example, the discovery of antibiotics to treat and cure many bacterial diseases was a major breakthrough in medical history. Healthcare providers, however, sometimes prescribe antibiotics unnecessarily for a variety of reasons, including pressure from patients with viral diseases such as the flu.
Because antibiotics have been prescribed too often or prescribed for the wrong diseases for many years, some bacteria have become resistant to the killing effects of these drugs. This resistance, commonly called antibiotic or drug resistance, has become a very serious problem, especially in hospital settings.
Bacteria that are not killed by the antibiotic become strong enough to resist the same medicine the next time it is given. Because bacteria multiply so rapidly, changed or mutated bacteria that resist antibiotics will quickly outnumber those that can be destroyed by those same drugs.
Viral diseases can be very difficult to treat because viruses live inside your body’s cells where they are protected from medicines in the bloodstream. Researchers developed the first antiviral drug in the late 20th century. The drug, acyclovir, was first approved by the Food and Drug Administration to treat herpes simplex virus infections. Only a few other antiviral medicines are available to prevent and treat viral infections and diseases.
Healthcare providers treat HIV infection with a group of powerful medicines that can keep the virus in check. Known as highly active antiretroviral therapy, or HAART, this treatment has improved and lengthened the lives of many suffering from this deadly infection.
Viral diseases should never be treated with antibiotics. Sometimes a person with a viral disease will develop a bacterial disease as a complication of the initial viral disease. For example, children with chickenpox often scratch the itchy skin lesions (sores) caused by the virus. Bacteria such as Staphylococcus can enter those lesions and cause a bacterial infection. A healthcare provider may then prescribe an antibiotic to destroy the bacteria. The antibiotic, however, will not work on the chickenpox virus, only on the staph bacteria.
Although safe and effective treatments and cures for most viral diseases have eluded researchers, there are safe vaccines to protect you from viral infections and diseases.
Medicines applied directly to the infected area are available by prescription and over the counter to treat skin and nail fungal infections. Unfortunately, many people have had limited success with them. Very powerful oral antifungal medicines are available only to treat systemic (within the body) fungal infections, such as histoplasmosis. Healthcare providers usually prescribe oral antifungal medicines with caution because all of them, even the milder medicines for skin and nail fungi, can have very serious side effects.
Diseases caused by protozoan parasites are among the leading causes of death and disease in tropical and subtropical regions of the world. Developing countries within these areas contain three-quarters of the world’s population, and their people suffer the most from these diseases. Currently, there are no vaccines to control parasitic diseases.
In many cases, controlling the insects that transmit these diseases is difficult because of pesticide resistance, concerns regarding environmental damage, and lack of adequate public health systems to apply existing insect-control methods. Thus, disease control relies heavily on the availability of medicines. Healthcare providers usually use antiparasitic medicines to treat protozoal infections. Unfortunately, there are very few medicines that fight protozoa, and some of those are either harmful to humans or are becoming ineffective.
The fight against the protozoan Plasmodium falciparum, the cause of the most deadly form of malaria, is a good example. This protozoan has become resistant to most of the medicines currently available to destroy it. A major focus of malaria research is on developing a vaccine to prevent people from getting the disease in the first place. In the meantime, many worldwide programs hope to eventually control malaria by keeping people from contact with infected mosquitoes or preventing infection if they can't avoid contact.
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Your immune system has an arsenal of ways to fight off invading microbes. Most begin with B and T cells and antibodies whose sole purpose is to keep your body healthy. Some of these cells sacrifice their lives to rid you of disease and restore your body to a healthy state. Some microbes normally present in your body also help destroy microbial invaders. For example, normal, good bacteria, such as lactobacillus in your digestive system, help destroy germs that find their way there.
Other important ways your body reacts to an infection include fever and coughing and sneezing.
Fever is one of your body’s special ways of fighting an infectious disease. Many microbes are very sensitive to temperature changes and cannot survive in temperatures higher than normal body heat, which is usually around 98.6ºF. Your body uses fever to destroy influenza viruses, for example.
Another tool in your immune system’s reaction to invading infection-causing microbes is mucus production. Coughing and sneezing help mucus move those germs out of your body efficiently and quickly.
Other methods your body may use to fight off an infectious disease include
Last Updated July 30, 2008