Much of the research on the transmission of the common cold has been done with rhinoviruses, which are shed in the highest concentration in nasal secretions. Studies suggest that it is most likely to transmit rhinoviruses in the second to fourth day of infection, when the amount of viruses in nasal secretions is highest. It has also been shown that using aspirin to treat colds increases the amount of virus shed in nasal secretions, possibly making the cold sufferer more of a hazard to others.
Hand-washing is the simplest and most effective way to keep from getting colds. Not touching the nose or eyes is another. Individuals with colds should always sneeze or cough into a paper tissue, and promptly throw it away. If possible, one should avoid close, prolonged exposure to people who have colds. Because viruses can survive up to three hours outside the nasal passages on inanimate objects and skin, cleaning environmental surfaces with a disinfectant might help prevent spread of infections.
The development of vaccines that could prevent the common cold has reached a difficult stage because of the discovery of many different cold viruses. Each virus carries its own specific antigens, substances that induce the formation of specific protective proteins (antibodies) produced by the body. Until we find ways to combine many viral antigens in one vaccine, or take advantage of the antigenic similarities they share, prospects for a vaccine are not great. Evidence that changes occur in common-cold virus antigens further complicate development of a vaccine. Such changes occur in some influenza virus antigens and make it necessary to alter the influenza vaccine each year. Only symptomatic treatments are available for uncomplicated cases of the common cold: bed rest, plenty of fluids, gargling with warm salt water, and aspirin or acetaminophen to relieve headaches or fever.
Several studies have linked the use of aspirin to the development of Reye’s syndrome in children recovering from influenza or chickenpox. Reye’s syndrome is a rare but serious illness that usually occurs in children between the ages of three and twelve years. It can affect all organs of the body, but most often injures the brain and liver. While most children who survive an episode of Reye’s syndrome do not suffer any lasting consequences, the illness can lead to permanent brain damage or death. It is recommended that children and teenagers not be given aspirin or any medications containing aspirin when they have any viral illness, particularly chickenpox or influenza.
Many doctors recommend these medications be used for colds in adults only when headaches or fever is present. Studies show that aspirin and acetaminophen can suppress certain immune responses and increase nasal stuffiness in adults. Non-prescription cold remedies, including decongestants and cough suppressants may relieve some cold symptoms but will not prevent, cure, or even shorten the duration of illness. Moreover, most have some side effects, such as drowsiness, dizziness, insomnia, or upset stomach and should be taken with care. Antihistamines may also have some effect in relieving inflammatory responses such as runny nose and watery eyes that are commonly associated with colds.
Antibiotics have no effect on viruses. These prescription medications should be used only for bacterial complications, such as sinusitis or ear infections, that can develop as secondary infections. Many people are convinced that taking large quantities of vitamin C will prevent colds or relieve symptoms; several studies involving children and adults have been conducted. To date, no conclusive results have shown that large doses of vitamin C prevent colds. The vitamin may reduce the severity or duration of symptoms, but there is no definitive evidence.
Taking vitamin C over long periods of time in large amounts may be harmful: it can cause severe diarrhea, a particular danger for elderly people and small children. In addition, too much vitamin C distorts results of tests commonly used to measure the amount of glucose in urine and blood. Combining oral anticoagulant drugs and excessive amounts of vitamin C can produce abnormal results in blood-clotting tests. Further, large amounts of vitamin C over time may facilitate the formation of kidney stones.
