- The Washington Times - Wednesday, December 15, 2004

Many people imagine that scientists should have found a way to rid the world of the common cold by now.

The task, however, is more complicated than it seems, says Dr. Margo Smith, director of the infectious-diseases section at the Washington Hospital Center in Northwest.

“There are at least 200 viruses that cause the common cold,” she says. “Each one of the viruses has a structure that’s very unique.”

On the surface, curing the common cold may not seem crucial in a world with many fatal diseases. The symptoms associated with the ailment, however, are among the largest contributing factors to job and school absenteeism in the country.

Nearly 22 million school days are lost each year to the common cold, according to the Centers for Disease Control and Prevention in Atlanta.

During the year, Americans suffer about 1 billion colds, according to estimates reported at the National Institute of Allergy and Infectious Diseases in Bethesda.

If scientists could figure out a way to kill a rhinovirus, a large group of viruses that cause the common cold, they probably would be successful at significantly reducing the amount of colds contracted, says Dr. John Bartlett, chief of the infectious-diseases division at the Johns Hopkins University School of Medicine in Baltimore.

More than 110 rhinoviruses that cause cold symptoms have been identified. Although each virus is different, Dr. Bartlett says he is hopeful that their similarities will be their downfall.

“If you could figure out how to kill one of them, you could kill all of them,” he says.

Unfortunately, Dr. Bartlett says, doctors and scientists have never been very good at treating viral infections.

Patients who receive a flu vaccination, for example, can still get influenza because the vaccine usually contains just three virus strains.

Acyclovir, the first anti-viral medication, was approved by the Food and Drug Administration in 1982 for treatment of herpes. The medication doesn’t cure the illness, though. HIV is another example of a virus that is fought with many drugs that don’t provide a cure.

Other viruses that cause the common cold are coronaviruses, adenoviruses, coxsackieviruses, echoviruses, orthomyxoviruses, paramyxoviruses, respiratory syncytial virus and enteroviruses.

Further, because so much of the population would use a government-approved medicine for the common cold, FDA safety standards have been more stringent than normal, Dr. Bartlett says.

“It will be very hard and expensive to get it through the FDA,” he says. “You’ve got to be so safe in terms of toxicity and drug interactions.”

However, if a drug were approved by the FDA, it would help a lot of people, Dr. Bartlett says. The average adult has about three colds a year.

“It ought to be a winner in the marketplace,” he says.

Because doctors lack a way to prevent and cure the common cold, they often overuse antibiotics, says Dr. Frederick G. Hayden, professor of internal medicine and pathology at the University of Virginia School of Medicine in Charlottesville.

In most instances, infections are viral and not bacterial, he says. Sometimes, a viral infection also can have a secondary bacterial infection.

“Antibiotics certainly won’t help the viral infection, and they have downsides,” Dr. Hayden says. “It drives the problem of antibiotic resistance.”

The use of Tamiflu has shown that early treatment with an anti-viral drug can decrease the length and severity of a virus, Dr. Hayden says. Tamiflu was approved by the FDA in 1999. The drug is for use by people who have noticed flu symptoms in the previous day or two.

Although the flu and the common cold are both caused by viruses, they represent different public health problems. Because there is not a vaccine to prevent the common cold, avoiding transmission of the virus is the key, says Dr. Allan Morrison, hospital epidemiologist at Inova Health System in Fairfax.

Usually, a cold virus enters the front nasal passages through contact with contaminated fingers or particles from coughing or sneezing. Even small amounts of viruses are enough to give a full-blown cold.

When people are in public places such as shopping malls, grocery stores and subway systems, they touch surfaces without knowing if they are contracting viruses. Crowded areas are key places where viruses can be transmitted, Dr. Morrison says.

Symptoms can begin 10 to 12 hours after a person is infected with a common cold virus. The peak of the infection usually occurs within 72 hours.

Washing hands often for at least 20 seconds and avoiding touching the face is crucial. Hand-sanitizing gels or wipes also are a good option.

“Young mothers carry them in their purses,” Dr. Morrison says. “You carry a hand wash with you without a sink.”

For people who are sick, using Kleenex Anti-Viral Tissue is an option for restricting the spread of germs, says Dr. Morrison, who is not affiliated with Kimberly-Clark Corp., the company that makes Kleenex. The middle layer of the tissues is supposed to kill cold and flu viruses, which doesn’t happen with regular Kleenex, he says.

“It won’t make you better sooner, but inventors of the Kleenex were using it as an attempt to block transmission of viruses,” Dr. Morrison says. “They are particularly good for families with younger children and for day care centers.”

Doctors have known for at least 50 years that children readily pass viruses, says Dr. William Jordan, former director of the division of microbiology and infectious diseases at the National Institute of Allergy and Infectious Diseases.

Because children haven’t acquired the level of immunity for viruses that many adults have, youngsters catch viruses easily. Adults who spend a lot of time around children who are sick also are more likely to contract viral illnesses, Dr. Jordan says. With more exposure to viruses, the chances of becoming ill increase.

“Children are virgin territory,” he says. “They are good disseminators of viruses. They usually have benign infections, but very frequently. Colds are a nuisance because they are so frequent.”

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