Cold, Common | Research & Encyclopedia Articles

Cold, Common

Dedicated researchers have searched for a cure or even an effective treatment for the common cold (rhinitis) for years. Discovering or constructing the agent that will be universally lethal to all the cold-causing viruses has been fruitless. A drug that will kill only one or two of the viruses would be of little use since the patient would not know which of the viruses was the one that brought on his cold.

The common cold differs in several ways from influenza or the flu. Cold symptoms develop gradually and are relatively mild. The flu has a sudden onset and has more serious symptoms the usually put the sufferer to bed, and the flu lasts about twice as long as the cold. Also influenza can be fatal, especially to elderly persons, though the number of influenza viruses is more limited than the number of cold viruses, and vaccines are available against certain types of flu.

Rhinoviruses, adenoviruses, influenza viruses, parainfluenza viruses, syncytial viruses, echoviruses, and coxsackie viruses--all have been implicated as the agents that cause the runny nose, cough, sore throat, and sneezing that advertise that you have a cold. More than 200 viruses, each with its own favored method of being passed from one person to another, its own gestation period, each different from the others, wait patiently to invade the mucous membranes that line the nose of the next cold victim.

Passing the cold-causing virus from one person to the next can be done by sneezing onto the person, by shaking hands, or by an object handled by the infected person and picked up by the next victim. Oddly, direct contact with the infected person, as in kissing, is not an efficient way for the virus to spread. Only in about 10% of such contacts does the uninfected person get the virus. Walking around in a cold rain will not cause a cold. Viruses like warm, moist surroundings, so they thrive indoors in winter. Colds are easily passed in the winter, because people spend more time indoors then than they do outdoors. However, being outdoors in cold weather can dehydrate the mucous membranes in the nose and make them more susceptible to infection by a rhinovirus.

In addition, cold-causing viruses mutate with regularity. Each time it is passed from one person to the next, the virus changes slightly, so it is not the virus the first person had. Viruses are obligate parasites, meaning that they can carry out their functions only when they invade another living cell.

The virus has a tough envelope surrounding its nucleic acids, the genetic material for any living thing. Once it invades the body, the virus waits to be placed in the location in which it can function best. Once there, it attaches to a cell by means of receptor areas on its envelope and on the cell membrane. The viral nucleic acid then is inserted into the cell nucleus and it takes over the functions of the nucleus, telling it to reproduce viruses.

Taking regular doses of vitamin C will not ward off a cold. However, high doses of vitamin C once a person has a cold may help to alleviate symptoms and reduce discomfort. Over-the-counter drugs to treat colds treat only the symptoms. They may dry up the patient's runny nose, but after a few days the nose will compensate and overcome the effects of the medication and begin to drip again. The runny nose is from the loss of plasma from the blood vessels in the nose. Some researchers assert the nose drip is a defensive mechanism to prevent the invasion of other viruses. Antibiotics such as penicillin are useless against the cold because they do not affect viruses.

Scientists agree that the old wives' remedy of chicken soup can help the cold victim, but so can any other hot liquid. The steam and heat produced by soup or tea helps to liquefy the mucus in the sinus cavities, allowing them to drain, reducing the pressure and making the patient feel better. The remedy is temporary and has no effect on the virus. Colds are usually self-limiting, and recovery usually occurs within a week.