Introduction to Viruses
How Can Viral Diseases Be Prevented and Treated?
There are a number of different routes by which a person can become infected with a virus. To contract some viruses, humans must come in direct contact with a source of infection, such as contaminated food, water, fecal material, or body fluids. Other viruses are transmitted through the air. Viruses that cause diarrheal disease, for example, usually are spread via a fecal-oral route or through ingestion of contaminated food. Alternately, viruses that cause respiratory infections, such as the flu, are often spread by coughing and sneezing. Good hygiene and frequent hand washing are simple but effective ways to reduce the spread of viruses and other microorganisms.
The most successful method to prevent viral infections is through vaccines. Vaccines stimulate the body’s natural defenses—the immune system—to combat viral infections. They consist of components of a virus, or weakened or killed whole virus particles. Many childhood viral infections virtually have been eliminated (at least in the developed world). Remarkably, the viral disease, smallpox, has been eliminated from the human population through vaccination. However, vaccines are not available for all viral diseases. For example, a vaccine against HIV is being sought urgently. Some viruses, such as HIV, mutate rapidly, making vaccine development extremely challenging.
Unfortunately, once viral infections occur, there is little that can be done to cure these diseases. In contrast to bacterial infections, antibiotics are useless against viral infections. For a few viruses, antiviral drugs exist that can relieve some symptoms of the disease. Drugs that inhibit HIV reproduction have been developed, but while these drugs may improve a patient’s quality of life for some time, they are not a cure, and eventually HIV-infected individuals will succumb to the disease.
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Video and transcript courtesy of Wah Chiu, PhD, National Center for Macromolecular Imaging at Baylor College of Medicine. Funding for the video provided by NCMI, NIH.