Bring on the fluids and the aspirin. This winter's flu epidemic, now at its peak, is joining forces with at least two other viruses to keep thousands of area residents home from school or work, and send many of them to the doctor.

"This year is one of those years where a fairly high percentage of kids in this whole area are sick," said a Children's Hospital virologist who has watched the flu, a cough-producing virus and a third virus that has caused diarrhea run rampant in recent weeks.

Area health officials reported higher than usual absence from schools -- considered the earliest and most reliable index of an epidemic -- in some parts of the District of Columbia, Maryland and Virginia.

Three out of 10 schools surveyed in DC. noted sharp rises in absentee rates during the past two weeks, according to the city's chief of communicable disease control. A Montgomery County Health Department spokesman said 17 percent of students were absent last week, compared with the usual 8 percent. Absences have increased in Arlington and were as high as 25 percent in one school last week, according to county officials. They also increased, but less dramatically, in Fairfax and Prince George's counties, according to health officials there.

Adults also are coming down with the viruses. One-third of the 200 or more patients seen daily at D.C. General Hospital's emergency room -- the city's busiest -- have what looks like the flu, according to Dr. Mona Harrison, the hospital's director of ambulatory services. She said the hospital is seeing 25 percent more flu cases this week than last.

"It's definitely on the rise," agreed Dr. George E. Keeler, an emergency physician at Washington Hospital Center. He estimated the emergency room is treating 20 or 30 patients a day who have the typical fever, muscle aches and cough of flu, with some complaining of cramps and diarrhea, too.

"We're seeing it in people from their 20s to their 80s," he said.

Doctors designated as "sentinel physicians" in Arlington were reporting four times as many cases of flu last week as two months ago, and deaths from pneumonia at Arlington Hospital -- sometimes a complication of flu in older people -- are twice as high as they were last winter, said Dr. Raymond Schwartz, chief of the county health services. But the increase, from eight deaths to 17, was not statistically significant, he said.

The Montgomery County Health Department, meanwhile, has recommended that hospitals and nursing homes limit visitors to the immediate families of patients, to prevent the illnesses from spreading.

Some doctors have the impression that this year's flu is keeping people down longer than usual. A normal attack lasts five to seven days, but Dr. Charles Christianson, a family practitioner at Fort Lincoln, said his patients have been sick for as long as two weeks. "My research assistant was unable to get out of bed for eight days straight," he said.

Nationwide, deaths from influenza and pneumonia have been at epidemic levels for the past four weeks, according to Dr. Richard Goodman, an epidemiologist at the federal Center for Disease Control in Atlanta.

He said most of the flu this winter is caused by Type B flu virus, which produces a milder illness than Type A, the virsus responsible for worldwide epidemics about every 10 years.

A handful of Type A infections also have occurred this winter, he said. The disease control center now is testing specimens sent from the Eastern Shore of Maryland, where health officials discovered an apparent outbreak of Type A flu -- the first in the area this year -- in Talbot County late last week.

The classic case of flu, which Goodman called "the all-overs" -- fever, weakness and aches, along with a cough and sore throat -- is being complicated in the Washington area by the two other viruses, which are more common than usual this winter.

Respiratory syncytial virus, which produces a bad cough and can make baby sick enough to be hospitalized, is at its peak now and will continue to cause illness into the spring, said the virologist at Children's Hosptial.

Rotovirus, which causes stomack pains, vomiting and diarrhea, both in children and adults, has been afflicting large numbers of local residents since late January, he said. He believes people who have been prostrated with both cough and diarrhea are suffering from not one virus, but two.

Goodman said influenza itself can cause nausea and diarrhea, but usually only in 15 to 20 percent of people who get it. He added that it is not clear whether the appearance of Type A virus in Maryland will prolong this winter's flu outbreak in the Washington area.

"It's like weather forecasting," he siad. "There's no way of saying for sure what's going to happen with the virus."