The Common Cold (Achoo!)

More than 200 different viruses are known to cause the symptoms of the common cold. Some, such as rhinoviruses, seldom produce serious illnesses. It is reported that children have about 6 to10 colds a year. If there are two or more young children in a home, the number of colds per child can be as high as 12 a year. Why? Because they are often in close contact with each other in daycare centers and schools.

Adults average about 2 to 4 colds a year, although the range varies widely. Women, especially those aged 20 to 30 years, have more colds than men, possibly because of their closer contact with children. On average, people older than 60 have fewer than one cold a year. Seasonal variation may relate to the opening of schools and to cold weather, which prompt people to spend more time indoors. The most common cold-causing viruses survive better when humidity is low—the colder months of the year. Cold weather also may make the inside lining of the nose drier and more vulnerable to viral infection. Cold symptoms can last from one to two weeks.

Viral causation of colds:

• Rhinoviruses (of the nose) cause estimated 30 to 35 percent of all adult colds; are most active in early fall, spring, and summer; grow best at 91 degrees F (temperature inside human nose). These viruses tend to cause more symptoms above the neck (stuffy nose, watery eyes, headache).
• Coronaviruses: three or four types infect humans with colds occurring primarily in winter and early spring. They are more likely to get into the trachea and bronchi and lead to fever and bronchitis)
• Other viruses (e.g., adenoviruses, parainfluenza, respiratory syncytial, enteroviruses, and coxsackieviruses) cause 10 to 15 percent of adult colds.
• Causes of 30 to 50 percent of adults colds (presumed to be viral) are unidentified.
• Research suggests that psychological stress and allergic diseases affecting the nose or throat may have an impact on one’s chances of getting infected by cold viruses.

Transmission of colds: (Incubation period is between 12 to 72 hours; usually 48 hours)

• Touching skin that may have cold viruses and then touching your eyes or nose.
• Touching environmental surfaces (e.g., telephones, stair rails, tables, doorknobs) that have cold germs on them and then touching your eyes or nose.
• Inhaling drops of mucus full of cold germs from the air.
• Studies suggest a person is most likely to transmit rhinoviruses in the second to fourth day of infection, when the amount of virus in nasal secretions is highest.
• Researchers have shown that using aspirin to treat colds increases the amount of virus in nasal secretions, possibly making the cold sufferer more of a hazard to others.

Prevention: Rhinoviruses can live up to 3 hours on skin and can survive up to 3 hours on objects such as telephones and stair railings. Cleaning environmental surfaces with a virus-killing disinfectant might help prevent spread of infection. One of the best ways to prevent transmitting a cold or infecting oneself is to wash your hands! If water isn’t available, CDC recommends using alcohol-based products made for washing hands. Avoiding coughers and sneezers if possible and using a tissue rather than a handkerchief are other suggestions for preventing infection.

Myth # 1: There is no evidence that one can get a cold from exposure to cold weather or from getting chilled or overheated. But, if one’s immunity has been lowered (e.g., due to poor nutritional habits, alcohol or other drug abuse, or chemotherapy), then this statement does not hold true. Myth # 2: Echinacea: research studies show that this herbal supplement may help if taken in early stages of a cold, but it does not prevent colds. Myth # 3: Vitamin C: to date, there is no conclusive evidence that shows large doses prevent colds. Vitamin C may reduce severity or duration of symptoms, but again there is no clear evidence to support this. The placebo effect probably plays an important role. Too much vitamin C taken over long periods may cause severe diarrhea in elderly and small children. Check our more information at http://www3.niaid.nih.gov/healthscience/healthtopics/colds/overview.htm

Dr. Scholl, of corn plaster fame, was once asked for his philosophy, to which he replied: “Early to bed, early to rise, work like hell and advertise.”