I wasn't planning to write about the flu this week, but because it is on my mind (and my chest and in my head and my throat) it seems appropriate. This year's, in case you haven't noticed, is a particularly nasty virus--high fever, headache, cough, sore throat and a general feeling of having been flung from the Washington Monument.

One area pediatrician confirms he is "seeing quite a lot of this really mean bug." Although he doesn't know its particular strain, "It isn't just flu," he declares, "it's in-flu-en-za."

The National Centers for Disease Control in Atlanta have reports of influenza in 121 cities and 37 states. It is not epidemic--even if feels that way when you get it.

"However," says Dr. Karl Kappus, epidemiologist at CDC headquarters in Atlanta, "there's a lot more of it around this year than last year. That was a most mild year. We're having a real flu season this time."

Kappus says it also feels worse if you smoke. A recent study done among Israeli soldiers showed that smokers tended to have more severe and protracted cases of the same flu than the nonsmokers.

According to Dr. Carl Brandt, virologist at Children's Hospital National Medical Center, there are two strains of Type A influenza around the Washington area. "It's usual for Type A to peak here in February," he says, but there are "a lot of other pathogens rolling around as well."

One, called Respiratory Syncytial Virus, says Brandt, has caused a lot of severe respiratory illnesses in small children over the past quarter of a century. "Yet practically nobody's ever heard of it." Even grandparents, he says, can catch that nasty illness from their grandchildren and then infect them all over again.

Researchers have learned that viruses can be spread through telephone mouthpieces as well as by coughs, sneezes and expressions of affection.

What to do? I tend to agree with the current wisdom that fevers are there to speed healing and, everything else being equal, should be left to run their own course. But this time everything else wasn't equal. Even my old standby, aspirin, only got my fever down to 101.

But because of a possible link to the condition known as Reye's Syndrome for children and young adults, aspirin should not be used at all in treating viruses like flu and chicken pox. After cool compresses and tepid baths, if any chemical is to be used at all, it should be acetaminophen which is in Tylenol and Anacin-3, for example.

Of course we called our doctor. Although sympathetic, he knew that we knew that he couldn't tell us anything to do that would make it better faster. That's the way flu is. Just stay in bed until it goes away; drink warm liquids (chicken soup is perfect); mellow out and hope for the best.

Antibiotics don't work on viruses. There are a few anti-virus medicines, like Amantadine, that are beginning to be seen on the market, but by the time they work, the worst is usually over. Their best usage is as a short-term preventative for older people and those with chronic diseases who may suffer potentially fatal complications.

Most high-risk people should have had flu shots in the fall--not always a guarantee either, because the flu virus tends to mutate so quickly that last year's vaccine often is just no good against this year's virus. However, in the case of this year's most prevalent flu strains, the vaccine--had you remembered to get it in time--would have worked.

Now a word about flu names. The scientists are reluctant to label the strains by names of the places of origin because they change so quickly. "Their real names are things like H1N1 or H3N2 our current crop ," says Dr. Kappus, "but we fall back to the place names Brazil, Bangkok because people's eyes just glaze over when they see those numbers . . ."

Now I don't know if the variety I had was H1N1 or what, but I do know it came from Rockville because I caught it from my husband who caught it in Rockville. Ever heard of the Rockville flu?

* A closing note on Heart Month--some hearty reading:

* The Pritikin Permanent Weight Loss Manual by Nathan Pritikin (Grosset & Dunlop, $14.95). Low-cholesterol, low-fat, low-protein diet that is high in complex carbohydrates. Recipes and exercise programs. Dean Ornish's heart study tends to validate some of the claims for the Pritikin program.

* The American Medical Association Book of Heart Care (Random House, $12.95). Easy-to-read, factual compendium of traditional medicine's fight against heart disease.

* The Heart (U.S. News Books, $16.95). Excellent and beautifully illustrated heart book for laymen. Part of a mini-encyclopedia of the body.

* The Relaxation Response by Herbert Benson, M.D. (Avon, $2.25). The simplest technique for a relaxation exercise.

* Stress, Diet and Your Heart by Dean Ornish, M.D. (Holt, Rinehart and Winston, $16.95). Putting it all together and coming out healthier.

For information on special programs and free pamphlets, write American Heart Association, Nation's Capital Affiliate, 2233 Wisconsin Ave. NW, Washington. D.C. 20007, or call 337-6400.

* Asthma and Allergies: A free seminar.

A public session with some of the area's top specialists in childhood allergies and asthma is scheduled for Saturday March 5 from 1 to 3 p.m. at Children's Hospital National Medical Center, second floor auditorium. The seminar is sponsored by the Metropolitan Washington Chapter of the Asthma and Allergy Foundation of America. Parents of asthmatic and allergic children will hear short talks on techniques for identifying the allergic child, new approaches to therapy, as well as some simple tricks for do-it-yourself prevention.

One hour will be devoted to questions and answers. No advance arrangements are necessary. The hospital is at 111 Michigan Ave. NW.