WHAT IS A VIRAL INFECTION ?
A virus is a tiny organism that causes an infection in the body. Viruses are made up of the genetic material known as DNA or RNA, which the virus uses to replicate. In order for a virus to survive, it must invade and attach itself to a living cell. It will then multiply and produce more virus particles.
By attaching itself to a host cell, the virus may either kill or alter the cell’s functions. When the cell dies, new types of viruses are released, and they infect other cells. This is how viruses cause disease. Generally, viruses will only infect one type of cell. For example, the cold virus will only infect cells of the upper respiratory tract.
Viruses can be transmitted in numerous ways, such as through contact with an infected person, swallowing, inhalation, or unsafe sex. Factors such as poor hygiene and eating habits can increase your risk of contracting a viral infection.
The external barriers, such as the skin and mucous membranes, are the first line of defense. The body’s immune defenses are triggered when the virus enters the body, and white blood cells (lymphocytes and monocytes) begin to attack and destroy the virus.
This type of general protection is referred to as innate or natural immunity.
Types of Viral Infections
Viruses can affect any part of the body or body system, and can cause infections such as the common cold, flu, gastroenteritis, chicken pox or herpes. The most common type of viral infections involves the respiratory tract.
The common cold is a frequently occurring viral infection and usually includes symptoms such as sneezing, stuffy nose, sore throat and coughing. Although colds are a minor infection of the nose and throat, a cold can last from two days to two weeks. Colds are highly contagious and are spread by fluids from sneezing or coughing, which contain the infection.
Influenza, also known as the “flu”, is a respiratory infection caused by viruses. The flu differs in several ways from the common cold. Symptoms of the flu include body chills, fever, headache, muscle ache and sore throat. Unlike many other viral respiratory infections, the flu can cause severe illness and life-threatening complications in many people. The flu is contracted in the same airborne manner as the common cold. For both cold and flu, the viruses are easily transmitted in highly populated areas.
The gastrointestinal system is also commonly affected by viruses with symptoms such as diarrhea and/or vomiting. Stomach viruses can be spread through contaminated food or water and can cause viral gastroenteritis, meaning inflammation of the stomach and intestines (small and large). Improper hand washing following a bowel movement or handling a diaper can spread the disease from person to person. Symptoms of gastroenteritis can include nausea with or without vomiting, diarrhea, low-grade fever and abdominal pain. Many people call gastroenteritis the “stomach flu”, although this virus is not a strain of Influenza at all.
The skin can also be infected by a viral infection such as the common wart or chicken pox. Chickenpox is an infectious disease; with most cases occurring in children under age 15, but older children and adults can also get it. It spreads very easily by human contact. Symptoms include itchy rash, fever and headache. The rash is blister-like and usually appears on the face, scalp or torso. The disease is usually mild and lasts 5 to 10 days, although adults and older children tend to get sicker from it. Chickenpox in a virus that stays in the body forever and in most cases a person who has had the virus will likely never contract it again.
Viruses such as herpes are caused by the herpes simplex virus (HSV). This infection can infect the mouth, genitals and anus. Oral herpes causes sores around the mouth and face, while genital herpes affects the genitals, buttocks and anus. Genital herpes is known as a sexually transmitted disease (STD) and it is transmitted through sexual contact through the mouth and genitals. This virus can be spread even when sores aren’t present. Like chickenpox, this virus will remain in the body forever; however, a person with herpes may continue to deal with reoccurrences or “outbreaks” for life.