 |
- What is a common cold?
- What are the causes of Common cold?
- What are the symptoms of Common Cold?
- How are common cold viruses transmitted?
- How can we control the spread of common colds?
|
|
1. What Is a Common Cold?
The common cold is a group of symptoms in the upper respiratory tract caused by a large number of different viruses. Although more than 200 viruses can cause the common cold, the perpetrator is usually the rhinovirus, which is to blame for causing 10% to 40% of colds. Also, the coronaviruses cause about 20% of colds and the respiratory syncytial virus (RSV) causes 10% of colds.
The rhinovirus (or other cold virus) enters your body through your nose or mouth and is easily spread when you touch someone or touch common objects (the computer keyboard or mouse, the telephone receiver, a doorknob, or eating utensils). If you aren't cautious about hand washing, you can spread the common cold to family, friends, co-workers, and people you've never met at a restaurant or the supermarket.
Top |
|
2. What are the causes of the Common Cold?
The most common causes of the common cold are viruses -- rhinoviruses, coronaviruses, and the respiratory syncytial virus (RSV). The rhinovirus group causes 10% to 40% of colds. The coronaviruses and RSV are responsible for 20% and 10% of cases, respectively.
• Common Cold Causes: Rhinoviruses
Rhinoviruses, the worst offenders, are most active in early fall, spring, and summer. More than 110 distinct rhinovirus types have been identified. These viruses grow best at temperatures of about 91 degrees, that perfect body temperature right inside the human nose. Most rhinoviruses seldom produce serious illnesses. Other cold viruses, such as parainfluenza and respiratory syncytial virus, produce mild infections in adults but can lead to severe lower respiratory infections, such as pneumonia, in young children.
• Common Cold Causes: Coronaviruses
Scientists think coronaviruses cause a large percentage of adult colds. These cold viruses are most active in the winter and early spring. Of the more than 30 kinds of coronaviruses, three or four infect humans. The importance of coronaviruses as a cause of colds is hard to assess because, unlike rhinoviruses, they are difficult to grow in the laboratory.
• Other Causes of the Common Cold
About 10 to 15 percent of adult colds are caused by viruses also responsible for other, more severe respiratory illnesses.
The causes of 30 to 50 percent of adult colds, presumed to be viral, remain unidentified. The same viruses that produce colds in adults appear to cause colds in children. The relative importance of various viruses in children's colds, however, is unclear because it’s difficult to isolate the precise cause of symptoms in studies of children with colds.
There is no evidence that you can get a cold from exposure to cold weather or from getting chilled or overheated.
• Stress, Allergies, and the Common Cold
There is also no evidence that your chances of getting a cold are related to factors such as exercise, diet, or enlarged tonsils or adenoids. On the other hand, research suggests that psychological stress and allergic diseases affecting your nose or throat may have an impact on your chances of getting infected by cold viruses.
Top |
|
3. What are the symptoms of Common Cold?
Symptoms usually show up about two days after a person becomes infected. Early signs of a cold are a sore, scratchy throat, sneezing, and a runny nose. Other symptoms that may occur later include headache, stuffy nose, watering eyes, hacking cough, chills, and general malaise (ill-feeling) lasting from 2 to 7 days. Some cases may last for two weeks. The common cold may be accompanied by:
- laryngitis (inflammation of the larynx or "voice box");
- tracheitis (inflammation of the membrane lining the trachea or "wind pipe") or
- bronchitis (inflammation of the bronchial membranes).
- These inflammations may make one more susceptible to more serious complications such as
- sinusitis (inflammation of sinus membranes) and
- pneumonitis (inflammation of the lungs).
Although no fatalities have been reported among otherwise healthy workers the disability is important because it affects work performance and industrial absenteeism.
Top
|
|
4. How are common cold viruses transmitted?
Colds are really not very contagious, compared to other infectious diseases. Close personal and prolonged contact is necessary for the cold viruses to spread. The viruses must get into the nose where they can infect the nasal membranes. The virus must attach to nasal cells after which the viruses can multiply. Inhaling contaminated droplets produced when someone else coughs or sneezes may be one way to catch a cold.
Cold viruses can remain infective even if they are outside the body for a few hours. You can catch a cold if you handle something that is contaminated with a cold virus and then stick your contaminated finger up your nose or rub your eyes. The cold viruses can reach the nose when you rub your eyes because the virus can be passed down the tear ducts that go from the eyes into the nasal cavities.
Top |
|
5. How can we control the spread of common colds?
You cannot cure a cold but you can help protect yourself from getting a cold by following good personal hygiene practices. Good hygiene practices include:
- washing hands properly and frequently
- covering the mouth when coughing or sneezing
- wiping noses using disposable tissues in a way that secretions are contained by the tissue without contaminating the hands
- avoiding rubbing the eyes with dirty hands
- avoiding nail biting (especially important for infections that are transmitted orally)
A healthy diet and getting sufficient sleep are also important in helping to prevent colds. Our immune system is also affected by stress. Studies have shown that people are more susceptible to getting colds after times of psychological stress.
Top |
| |
| |
|
