Researchers at Children's Hospital National Medical Center yesterday confirmed that they have isolated the Russian flu virus from the throat washings of two children treated early last week in the hospital's emergency room.

At the same time, local college student health services are being swamped by students complaining of the headaches, body aches, sore throats, coughs and fevers associated with the influenza caused by the A/USSR/77 H1N1 virus.

The Herker School, a private boys' preparatory school in Potomac, Md., was closed yesterday and won't reopen until next Tuesday. "I've got so many kids out that we decided the only thing to do was close the school," said headmaster Col. John Kieffer (USAF-Ret).

Kieffer said that of the 110 students who attend the school, 40 are sick and "another 10 ought to be at home . . . We've been fighting it since last Friday," he said.

Dr. Naomi Schaub, director of the student health service at George Washington University, said "we've been seeing about 70 or 80 patients a day with a flu-type illness, and we're getting a lot more phone calls. Usually it's more like 20 or 30 cases a day. This appears to be a different flu from what we were seeing three weeks ago. It's mostly the younger students and the students who live in the dorm," said Schaub.

The flu Schaub and other health workers were seeing a few weeks ago - and are still seeing some of - were A-Texas and A-Victoria, both H3N2 viruses that have been prevalent in this country for the past several years.

The symptoms caused by the Russian flu are generally of shorter duration, usually lasting about three to five days, and seem to involve more body aches than the A-Exas and A-Victoria varieties.

By yesterday new cases of flu at the Naval Academy had dropped to 45, but some 1,200 midshipmen remained in bed as a result of the illness that has so far infected about 75 percent of the 4,300 midshipmen. None was hospitalized. Ill midshipmen were generally confined to their rooms and treated with aspirin and cough medicines.

Health service workers at the University of Maryland reported a large number of students complaining of the Russian flu symptoms, as did doctors at Howard and Georgetown universities.

Dr. Martin Levey, the D.C. government's epidemilogist, said there has been a marked increase in flu cases in the District public schools, but he will not have confirmation until late today whether the flu is Russian or the earlier A-Texas or A-Victoria.

Neither Fairfax County schools, the most numerous in Northern Virginia nor Montgomery County Schools have reported any unusual absenteeism for this time of the year, but there have been reports of influenza outbreaks in some Prince George's County schools.

The first confirmed outbreak of the Russian flu in this country occurred in a high school in Cheyenne, Wyo. during the week of Jan. 15. There have been other confirmed outbreaks in Laramie, Wyo., at the Air Force Academy in Colorado Springs, Colo., at Air Force bases in Denver and Cheyenne, in Tecumseh, Mich., East Lansing, Mich., San Antinio, Tex. and at the U.S. Military Academy in West Point, N.Y.

It is virtually impossible at this point to tell how the virus will spread. I could blanket the country within the next four to eight weeks, or it could "seed" itself, spreading slowly, individual case by individual case, until next flu season.

While it is possible to speculate that the flu came to this country from a U.S. Air Force base in England, which experienced an earlier outbreak to an Air Force facility in Cheyenne. Dr. Alan Hinman, director of the federal Center for Disease Control's division of immunology, said there's "probably not that knid of nifty tie. It's as likely that theare were separate introductions as it is that it spread from one place to another."

There are, however, at least two places where experts say it's possible to make an educated guess how the virus spread from one population group to another.

On Jan. 23 the outbreak began at West Point, and by the 27th some 200 to 300 cadets were reporting to sick call each day. By the 30th the epidemic had peaked at the Military Academy.

By the 27th, Dr. Rita Jaeger, director of the student health service of Vassar College, the predominantly women's school in nearby Poughkeepsie, N.Y., noted an increase in flu cases.

"I know there are a few students here who go out with men from West Point," said Dr. Jaeger, who added that the flu is now "going around the campus very rapidly. We've had 600 or 700 come in to clinic, and there are probably that many sitting in their rooms."

A similar situation occurred in Colorado Springs home of the Air Force Academy. "There is evidence of influenza activity in a couple of the high schools in the Colorado Springs area," said Dr. Stan Furgeson, assistant director of disease control and epidemiology for the Colorado Department of Health.

And, said Ferguson, there "is some socialization and dating of cadets by some of the older girls" in the high schools.

As is often the case with influenza epidemics, the first outbreaks of the Russian flu in this country have been among military populations. The reasons for that phenomenon is not clear.

"There are things about disease mechanics and military populations that we don't well understand," said Ferguson, who nevertheless speculated that the spread within military populations has something to do with "the crowding, mobility, social, physcial and psychological stresses on that population."

Both the Asian flu epidemic of 1957 and the Hong Kong flu epidemic of 1968 began among military populations. Looking back many months after those outbreaks were long over, epidemiologists were able to trace some portions of the outbreaks to single individuals or groups of individuals.

The Asian flu, for example, reached this country in June 1957 via a Pakistani ship that landed at the navel base at Newport, R.I. There were isolated outbreaks around the country, and on June 26 there was an outbreak at a religious convention of 1,688 persons in Iowa.

Those persons returned to the 43 states from which they had come, just as some 1,000 infected boy scouts returned in Valley Forge, Pa. Those persons, and others involved in sporadic outbreaks, seeded their Communities until, by the week of Oct. 13-19, with children back in school and cool damp weather setting in, there were 12,238,000 cases of flu reported all over the country.