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Overview - Treatment

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.

For Bacteria

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.

Doctors, however, sometimes prescribe antibiotics unnecessarily for a variety of reasons, including pressure from patients with viral infections. Patients may insist on being prescribed an antibiotic without knowing that it won't work on viruses. Colds and flu are two notable viral infections for which some doctors send their patients to the drugstore with a prescription for an antibiotic.

Because antibiotics have been overprescribed or inappropriately prescribed over the years, bacteria have become resistant to the killing effects of these drugs. This resistance, called antimicrobial 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's 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.

For Viruses

Viral diseases can be very difficult to treat because viruses live inside the body's cells where they are protected from medicines in the blood stream. Researchers developed the first antiviral drug in the late 20th century. The drug, acyclovir, was first approved by the U.S. 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.

Health care professionals treat HIV infection with a group of powerful medicines which can keep the virus in check. Known as highly active antiretroviral therapy, or HAART, the new treatment has improved 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 skin sores caused by the viral infection. Bacteria such as staph can enter those lesions and cause a bacterial infection. The doctor may then prescribe an antibiotic to destroy the bacteria. The antibiotic, however, will not work on the chickenpox virus. It will work only against staph.

Unfortunately, safe and effective treatments and cures for most viral diseases have eluded researchers, but there are safe vaccines to protect you from viral infections and diseases.

For Fungi

Medicines applied directly to the infected area are available by prescription and over the counter for treating skin and nail fungal infections. Unfortunately, many people have had limited success with them. During the 1990s, oral prescription medicines became available for treating fungal infections of the skin and nails.

For many years, very powerful oral antifungal medicines were used only to treat systemic (within the body) fungal infections, such as histoplasmosis. Doctors usually prescribe oral antifungal medications cautiously because all of them, even the milder ones for skin and nail fungi, can have very serious side effects.

For Protozoa

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 populations suffer the most from these diseases. Controlling parasitic diseases is a problem because there are no vaccines for any of them.

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, control of these diseases relies heavily on the availability of medicines. Doctors usually use antiparasitic medicines to treat protozoal infections. Unfortunately, there are very few medicines that fight protozoal infections, 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 meantime, many worldwide programs hope to eventually control malaria by keeping people from contact with infected mosquitoes or from getting infected if contact can't be avoided.



National Institute of Allergy and Infectious Diseases, USA.