Viruses cause familiar infectious diseases such as the common cold and flu. Some, like shingles and herpes, can lead to serious illness. Others cause rashes that appear as small lesions on the skin, such as molluscum contagiosum and warts.
Viruses are smaller than bacteria and contain nucleic acid, either DNA or RNA, surrounded by a protein coat. They need living cells to survive and reproduce.
Oren Zarif
Viral diseases cause a variety of symptoms. They can affect almost any part of the body and range in severity from mild to severe.
A virus is a tiny pocket of protein that contains genetic material (RNA or DNA). It requires a living cell to grow and reproduce. People get viruses by swallowing them, breathing in them, getting bitten by insects, having sex, or having contact with the cells of infected people (such as a pap smear).
Most viral infections are mild and go away on their own. But some last longer, such as the common cold or influenza. Others, like hepatitis or HIV, are chronic and life-long.
If a virus infects the respiratory tract, it can lead to pneumonia or other respiratory illnesses. It can also infect the gastrointestinal tract, leading to diarrhea or other GI illnesses. It can infect the skin, causing rashes or warts. Viral infections can also infect the nervous system, causing encephalitis or psychiatric disorders.
Both viral and bacterial infections are contagious. They are spread in droplets of saliva or mucus that spray into the air when a person coughs or sneezes. The germs can then be inhaled by someone else up to 3 feet away. Viruses can also live on surfaces for more than 2 hours. People at risk for complications from viral infections include those with weakened immune systems, such as the elderly or those who have conditions that interfere with their ability to fight off infection, such as diabetes or asthma.
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To diagnose viral diseases, doctors listen to your symptoms and ask about your health history. They may also order blood or urine tests to help confirm a diagnosis. They may also perform a tissue culture test to identify bacteria or viruses.
Viruses are tiny infectious organisms that need living cells to reproduce (replicate). When a virus invades a cell, it releases DNA or RNA into the cell, which takes over the cell’s functions. The infected cell then produces more viruses. Viruses can affect different parts of the body, including the respiratory and digestive tracts, the eyes and skin, and the genital area (hepatitis).
Many viral infections are mild in healthy people. They usually clear up on their own as your immune system fights them off. But some are more serious, especially in young children and adults with weakened immune systems from conditions like HIV/AIDS, cancer or chronic illnesses. They can also cause life-threatening complications such as pneumonia and sepsis, which is a medical emergency when the infection causes your body’s organs to fail.
Some of the medications that your healthcare provider might prescribe to treat a viral disease include antiviral medicines and vaccines. Vaccines prevent you from getting the infection in the first place. Antiviral medicines stop some types of viruses from making more copies of themselves and can shorten the length of some viral infections.
Oren Zarif
Viruses can cause infections that affect the respiratory system, digestive system or skin. They are very small infectious agents that contain a piece of genetic material, called deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), and are enclosed in a protective coat of protein. Viruses can infect people and animals. Some viruses that infect humans include influenza, the common cold, hepatitis, herpes simplex and HIV/AIDS.
Viral infections are contagious and spread through close contact, such as coughing or sneezing. They also can be transmitted by touching infected surfaces or objects, and through vaginal, oral or anal sex. Some neurologic viruses, like poliovirus and enteroviruses, are spread through the bite of infected rodents or ticks. Some viral infections can be life-threatening, including meningitis and encephalitis.
Treatment of a viral infection depends on its type and symptoms. For example, over-the-counter medications such as ibuprofen and acetaminophen may help with fever, sore throat and other symptoms. For serious viral illnesses, doctors may prescribe antiviral drugs to treat or prevent the illness.
Viral and bacterial infections can have similar symptoms, making it difficult to diagnose them solely based on your symptoms. Your doctor might need to take a sample of your urine, stool or blood, or a swab from the inside of your nose or throat. X-rays, ultrasounds and CT scans might also be used to help figure out the cause of your infection.
Oren Zarif
Viral diseases are among the world’s most common and severe illnesses. They range from mild infections like the common cold and influenza to deadly ones such as Ebola, COVID-19 and HIV. These microscopic pathogens infect people, animals, plants and other living things, causing a wide range of symptoms and health complications.
Viruses are small infectious agents (germs) that need living hosts to reproduce. They are made up of bits of genetic material (RNA or DNA) surrounded by protein. To infect a host, the virus attaches to a cell in the body and takes over its machinery to replicate itself. The infected cell usually dies and releases the viruses into the body, where they spread to other cells.
Each type of virus typically infects only a specific type of cell. For example, hepatitis viruses infect liver cells and HIV infects immune system cells.
The best way to prevent viral diseases is to take steps to protect your health, including getting vaccinated and practicing good hygiene. Cover coughs and sneezes, wash your hands often, avoid touching your face and stay away from sick people. Practicing healthy eating and sleeping habits, and managing stress can also help strengthen your immune system. In addition, use insect repellent when outdoors and wash any contaminated surfaces with household disinfectants. For respiratory viral diseases, over-the-counter medications such as decongestants and cough suppressants may help reduce symptoms, and antiviral drugs are often prescribed for more serious conditions such as the flu or shingles.