Issue date: Jan 9, 2000

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Special Health Report: Immunity

Colds and flu: Do you know the facts?
Test yourself with this true-and-false quiz.

1.Cold viruses can spread from hard surfaces as well as direct contact with a sick person.

TRUE: Many of the more than 200 viruses that cause the common cold live for several hours on hard surfaces. Touching a doorknob or telephone, for example, and then touching your nose or eyes can transmit the virus.

2.Regular soap is as effective as antibacterial soap for washing germs off your hands.

TRUE: Washing vigorously with any kind of soap removes skin oils that contain germs. (In any case, colds and flu are caused by viruses, not bacteria.) Also effective for killing viruses on surfaces: rubbing alcohol and bleach.

3.Colds are spread mainly by coughs and sneezes.

FALSE: Studies suggest that colds are spread more by contact (shaking hands, sharing phones) than by airborne particles. The flu, on the other hand, is rapidly spread by coughs and sneezes.

4.Flu season comes in winter because the viruses thrive in the cold.

FALSE: Winter is when people spend time indoors together and spread the virus. In the tropics, influenza is a year-round phenomenon.

5.Colds, flu and strep throat are all cured by antibiotics.

FALSE: Of the three, only strep throat is caused by bacteria, so it's the only one cured by antibiotics.

6.Flu symptoms include fever, fatigue, muscle aches, runny nose, nausea and diarrhea.

FALSE: True influenza doesn't involve gastrointestinal distress. Those symptoms are caused by other viruses or bacteria.

7.You can develop antibiotic-resistant infections when you take an antibiotic.

TRUE: Bacteria that have been exposed to the antibiotic but have developed ways to fight them survive. They can then multiply and cause symptoms. You can transmit these resistant bacteria to others, who also may become ill.

8.Some people get the flu from the flu vaccine.

FALSE: The current vaccine contains only dead virus that cannot cause the illness. Next year, however, look for live "attenuated" (weakened) virus shots or nasal spray, which better spur immunity.

9.Colds and flu are contagious only in the earliest stages.

FALSE: The flu remains contagious for five to seven days from the onset of symptoms; colds, for three to four days.
-- Monika Guttman

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Is it a cold or the flu?

Before you choose a treatment, it helps to know what you have. Distinguishing between a cold and the flu can be tricky. To be certain, doctors now can perform a quick office test that identifies influenza. The test eventually will be available as a home kit. Meanwhile, here are symptoms to look for.

Symptoms	Cold	Flu
Fever	Rare	Characteristic, high (102-104 degrees); lasts 3-4 days
Headache	Rare	Prominent
General aches, pains	Slight	Usual, often severe
Fatigue, weakness	Quite mild	Can last up to 3 weeks
Extreme exhaustion	Never	Early and prominent
Stuffy nose	Common	Sometimes
Sneezing	Usual	Sometimes
Sore throat	Common	Sometimes
Chest discomfort, cough	Mild to moderate, hacking cough	Common, can become severe
Complications	Sinus congestion or earache	Bronchitis, can be life-threatening
SOURCE: National Institutes of Health

Information about flu surveillance and vaccination is available through the Centers for Disease Control's toll-free Voice Information System (1-888-232-3228) or online at www.cdc.gov/ncidod/diseases/flu/weekly.htm. October through May, information is updated weekly.

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The future of colds and flu
A cure for colds may be on the horizon, but flu will kill again.

A search for the cure. A cure for the common cold is hard to find because of basic biology. Many, many viruses cause colds and flu, and exposure to one virus does not cross-protect for another, says Frederick G. Hayden, infectious-disease specialist at the University of Virginia. Also, the body attacks cold viruses partly through an immediate immune response instead of relying on stored antibodies (from prior exposure or inoculation). On the radar: a drug called Pleconaril that inhibits the attachment of the cold virus to cells. Another drug in the works (known as AG7088) stops the virus from replicating once it has invaded the cell.

Preparing for a "plague." Flu pandemics come in cycles every two or three decades, so experts warn that the United States is due for another pandemic like the 1968 Hong Kong flu outbreak that killed 34,000 Americans. The lethal avian influenza that appeared in 1997 (it killed a third of the 18 people infected in Asia) "was a warning sign," says Linda Lambert, influenza program officer at the National Institutes of Health. The virus that caused it, H5N1, apparently passed from chickens to humans, surprising researchers who had believed that such transmission was not possible. H5N1 never learned to pass from human to human, but Lambert says "nobody will be surprised if it surfaces again."

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