A viral infection is any type of illness or disease caused by a virus, a type of microbe. A viral infection occurs when a virus enters the body through such processes as breathing air contaminated with a virus, eating contaminated food, or by having sexual contact with a person who is infected with a virus. A viral infection may also be caused by an insect bite. In a viral infection, the virus invades the inside of the body’s cells in order to reproduce. A virus then spreads to other cells and repeats the process.
This process of viral infection results in a variety of symptoms that vary in character and severity depending on the type of viral infection and individual factors. Common symptoms of a viral infection includefatigue, flu-like symptoms and fever.
Many types of viral infections, such as a cold, are self-limiting in generally healthy people. This means that the viral infection causes illness for period of time, then it resolves and symptoms disappear. However, some people are at risk for developing serious complications of viral infection. In addition, certain types of viral infections, such as HIV/AIDS, are not self-limiting and cause serious complications and are eventually fatal.
There are many types of viruses that cause a wide variety of viral infections or viral diseases. For example, there are over 200 different viruses that can cause a cold or an upper respiratory infection. Other common viruses include the influenza virus, which causes influenza or the flu. The Epstein-Barr virus and the cytomegalovirus cause infectious mononucleosis. The varicella zoster virus causes shingles, and chickenpox, and HIV causes AIDS.
Viral diseases are extremely widespread infections caused by viruses, a type of microorganism. There are many types of viruses that cause a wide variety of viral diseases. The most common type of viral disease is the common cold, which is caused by a viral infection of the upper respiratory tract (nose and throat). Other common viral diseases include:
- Flu (Influenza)
- Human immunodeficiency virus (HIV/AIDS)
- Human papillomavirus(HPV)
- Infectious mononucleosis
- Mumps,measles and rubella
- Viral gastroenteritis (stomach flu)
- Viral hepatitis
- Viral meningitis
- Viral Pneumonia
Viral diseases are contagious and spread from person to person when a virus enters the body and begins to multiply.Common ways that viruses spread from person to person include:
Symptoms of viral infection vary depending on the type of viral infection, the area of the body that is infected, the age and health history of the patient and other factors. The symptoms of viral infection can also resemble symptoms of other diseases, such as bacterial infections.
Symptoms may affect almost any area of the body or body system and include fever,chills, headache, stiff neck, irritability, enlarged glands, diarrhea, nausea, vomiting, rash, abdominal pain, sore throat, ear pain, cough,weight loss, fatigue, body aches, and other flu-like symptoms.
In infants, signs of viral infection can include excessive crying, excessive sleepiness, difficulty with feeding, and a bulging of the soft spot on the top of the head.
Many viral infections, such as upper respiratory infection and seasonal influenza, are self limiting. People who are generally healthy are often able to survive these infections without developing serious complications. However, even young and healthy people may develop serious complications to some viral infections. For example, women infected with certain strains of HPV are at risk for developingcervical cancer.
Certain risk factors make it more likely that a person will develop serious, even lethal, complications from a viral infection. People who are generally most at risk for developing complications include those who have a compromised immune system due to such diseases as HIV/AIDS or combined immunodeficiencies. People who take certain medications, such as corticosteroids, which suppress the body’s natural immune response, are also at risk. Other risk factors include malnutrition, high stress levels and being very young or very old.
Complications of a viral infection can include a secondary bacterial infection, pneumonia,dehydration, shock, the development of some forms of cancer and coma.
Symptoms of viral diseases vary depending on the specific type of virus causing infection, the area of the body that is infected, the age and health history of the patient, and other factors. The symptoms of viral diseases can affect almost any area of thebody or body system. Symptoms of viral diseases can include:
- Flu- like symptoms (fatigue, fever, sore throat, headache, cough, aches and pains)
- Gastrointestinal disturbances, such as diarrhea, nausea and vomiting
- Malaise (general ill feeling)
- Stuffy nose, nasal congestion, runny nose, or postnasal drip
- Swollen lymph nodes
- Swollen tonsils
- Unexplained weight loss
WHAT CAUSES VIRAL DISEASES?
Viral infections occur when a virus enters the body and invades the inside of the body’s cells in order to reproduce. If the body’s immune system is unable to fight off the virus, it multiplies and spreads to other cells, repeating the process and leading to a widespread infection.
TYPES OF VIRUSES:
There are many types of viruses that cause a wide variety of viral infections or viral diseases. In fact, there are more than 200different viruses that can cause a cold or an upper respiratory infection. Other common viruses include the following:
- Epstein-Barr virus causes infectious mononucleosis (cytomegalovirus causes a very similar disease in some people)
- Human papillomaviruses (HPV) cause HPV infection, cervical dysplasia, genital warts, and cervical cancer.
- Influenza viruses,such as H1N1, cause influenza (flu).
- Respiratory syncytical virus (RSV) causes lower respiratory tract infections in young children.
- Rhinoviruses cause the common cold
- Rotavirus, enteroviruses and noroviruses cause viral gastroenteritis.
- Varicella zoster virus causes shingles and chickenpox
- West Nile virus causes west nile fever.
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.
- No vaccine or specific antiviral treatments for West Nile virus infection are available.
- Over-the-counter pain relievers can be used to reduce fever and relieve some symptoms
- In severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care.
The first step in treating viral infection is preventing its occurrence and spread. Vaccines are available to prevent some common viral infections, such as chickenpox, shingles, influenza, HPV,hepatitis B, hepatitis A, measles and mumps.
Prevention of the spread of harmful viruses that cause viral infection also includes frequent hand washing and covering the mouth and nose with a tissue during sneezing or coughing. It is also important to avoid contact with a person who has a viral disease. Prevention of sexually transmitted viral infections, such as HIV/AIDS includes abstaining from sexual contact. The proper and consistent use of male and/or female condoms also provides some protection.
Treatment of viral infections varies depending on the specific virus and other factors. However, treatment of viral infections generally includes rest, increased fluids, good nutrition, and may require hospitalization and intensive care, especially if complications occur.
Antibiotics treat bacterial infections and are ineffective for the treatment of viral infections.
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.