He thought it was a woman's disease. But when Wayne Jones, 38, a Northern Virginia truck dispatcher, went to Alexandria Hospital last October for back surgery, he wound up with toxic shock syndrome.

An infection in the incision for his operation triggered "a six-day period when I was so sick I didn't know what was going on."

"I was almost ready to go home," he remembered. "But I started having a fever. My kidneys failed. I was in intensive care. It's six days I just can't account for. I was so sick I couldn't talk hardly. But I remember telling my wife I didn't want to die."

Toxic shock syndrome has not gone away. Hundreds, and perhaps thousands, of Americans came down with it last year--men, women and children of all ages. But one group is most vulnerable: women 15 to 24 who use highly absorbent tampons.

Debbie Headlee got toxic shock syndrome last August. She was 16.

"I was under the electric blanket freezing," she said. Then she got a rash, her temperature soared to 106, and she was rushed to Montgomery General Hospital in Olney. Her blood pressure dropped to a barely life-sustaining level.

"There was one point," said her mother, "when I looked at Debbie and thought, 'My God, she has died.' "

Headlee was using a tampon when she got sick. Seventy percent of all American women of childbearing age use tampons. But the widespread use of this 20th-century product seems to promote a 20th-century disease.

Toxic shock syndrome is one of a new class of diseases of technology, "a new way for an old germ to get at us," a Connecticut nurse said.

Toxic shock is caused by the one bacterium so common that almost everyone knows its name--"staph," Staphylococcus aureus in the medical textbooks. Eighty-five percent of all cases occur in menstruating women, 98 percent of whom have used tampons, but toxic shock also may start in operative wounds, since colonies of staph germs inhabit every hospital, or in infected burns, cuts, abscesses, boils or insect bites. Women may get it during childbirth, or when a diaphragm is kept in place more than 12 to 18 hours.

The national death rate among toxic shock victims is 3.3 percent. In Minnesota, a 3-month-old boy died after a wound infection on his heel. A sinus infection sent a woman, 81, into toxic shock.

"We've had three deaths in the last two months, two in menstruating women, one in a man with a wound infection. We've had three cases in the last seven days. This disease is still a problem," said a Minnesota health official.

Some strange illnesses, which now seem unmistakably similar to toxic shock, were recorded as early as 1927, but in the mid-'70s young women began to get them with increasing frequency.

Dr. James Todd, a Denver pediatrician, reported that between 1975 and 1977 he had found seven children and adolescents with what he correctly diagnosed as a "new and severe" staph infection. He named it "toxic shock syndrome," and reported this in a medical journal. Four of those patients were girls of menstrual age.

On the evening of Dec. 3, 1979, in Madison, Dr. Russell Chesney told his wife, Joan, also a doctor, of a puzzling case. A healthy teen-ager had suddenly developed a high fever and gone into shock as her blood pressure dropped dangerously. Two days later residents rushed to her office to ask her to see a girl, 15, with kidney failure and shock.

Later that afternoon she listened in amazement as yet another doctor told of a 23-year-old woman who came close to dying after being stricken with vomiting, diarrhea and fever, then falling blood pressure, while menstruating.

"Things clicked," Joan Chesney remembered. "I wrote a note saying, 'Do you think this could be toxic shock syndrome?' " The Madison doctors alerted Dr. Jeff Davis of the Wisconsin Health Department. He soon recorded five cases among menstruating women. In January his friends in the neighboring Minnesota Health Department noted five more, and called the Centers for Disease Control in Atlanta.

The CDC assigned Dr. Kathryn Shands, a young officer from its Epidemic Intelligence Service, to investigate. Within days, a doctor called about the puzzling case of a girl, 14, taken to the hospital semi-conscious with kidney, liver and nerve damage and a red body rash.

Shands rushed over to see her, and found that the girl had been using tampons.

"It was an absolutely classical toxic shock case," said Shands. "My major impression was that this was an incredible disease to strike a completely healthy adolescent girl."

By mid-February the disease's usual symptoms were well recognized: fever, rash, drop in blood pressure, involvement of "at least three organ systems"--meaning possible heart, muscle, gastrointestinal, lung, kidney, liver or nervous system problems--then, after a week or so, peeling skin and often temporary hair loss.

In May, the CDC went public, alerting doctors that a new nationwide disease had stricken 55 persons, 52 of them young women, and killed seven. By June the case total had reached 131. In August, 131 more cases were reported. It was the disease's peak month.

The CDC and the Midwest health departments made a series of studies comparing toxic shock victims with a healthy, age-matched control group. It became clear that most toxic shock patients, like 49 million other American women, had used tampons.

And 71 percent of the stricken women had used Rely tampons. Procter & Gamble had introduced Rely in 1974 as the first of the super-absorbent varieties, with strong appeal to women seeking more freedom in work and sports.

Rely had a new, highly absorbent ingredient, carboxymethylcellulose, also used in paper towels. Rely also had a new shape to expand radially instead of lengthwise for better fit. "It even absorbs the worry," the Rely label said.

Rely had quickly captured nearly a third of the $400 million-a-year tampon market. But in September, 1980, confronted by the CDC data, Procter & Gamble halted Rely sales.

In August, the Minnesota Health Department began still another study in association with Wisconsin and Iowa. By the time the Tri-State Study was completed in January, 1981, the CDC's case count had begun dropping. The CDC concluded that removing Rely had removed one main cause of the illness.

The Tri-State Study came to a different conclusion: the risk of toxic shock was most closely associated not with Rely or any other brand but with a tampon's absorbency.

"All five tampon manufacturers had high-absorbency products," said Dr. Michael Osterholm of the Minnesota Health Department. "Rely was no more absorbent than some others." In a sense, he said, Rely was singled out because it had most of the high-absorbency market.

CDC doctors called the Tri-State results "highly interesting" but still unproved. They said the increased risk for Rely was real. A National Academy of Sciences-Institute of Medicine study group agreed.

The CDC recorded only 527 cases, with 15 deaths, in 1981, compared with 1980's 866 cases and 42 deaths. (Full 1982 figures have not come in from all states.) But in Minnesota, which continued to watch every hospital from January, 1980, through July, 1981, the case load failed to drop despite Rely's disappearance.

In Utah, another state keeping close watch, case reports still average two or three a month, compared with four a month at the peak of the scare. This sparsely populated state had 32 cases in 1982, up from 21 the previous year.

"We think cases dropped when all tampon use dropped in 1981," said Craig Nichols of the Utah Health Department. "We think women have become more complacent again, tampons have come back and so has toxic shock." Tampon use has returned nearly to pre-toxic scare levels.

Although CDC officials get just 40 or 50 official case reports every month--500 or 600 a year when all state figures are reported--one official thinks there may really be 3,100 to 8,800 cases yearly. Scrutiny by most state health departments has become sketchy. And even these numbers may be only the tip of the iceberg.

Many cases may be mistaken for other disorders. The official "case definition" for statistical precision fits only the most serious cases, and doctors say they feel there are many less severe and even mild ones.

The uncertain figures produce varying estimates of a menstruating woman's risk of getting the disease--from 3 or 4 chances in 100,000 each year, according to the CDC, to 1 in 2,500 of getting some form of it, said Dr. Patrick Schlievert, a University of Minnesota bacteriologist.

Procter & Gamble maintains there was never any defect in Rely tampons. It is fighting at least 400 lawsuits by stricken women or their survivors. Other tampon makers face hundreds more.

Procter & Gamble has settled one case out of court and is appealing one $300,000 verdict. Johnson & Johnson won one case, but lost another in which a jury awarded a woman $10.5 million. The sum may be reduced in further proceedings. International Playtex, too, won one case and lost another. There have been many more undisclosed settlements, according to the OB/GYN Litigation Reporter.

The manufacturers, the CDC and the Midwest health departments agree on one thing: more investigation is needed to establish the role of relative absorbency, as well as the incidence of toxic shock. One proposed study would cost $1.7 million. But in today's economy, with other diseases and a limited CDC budget, toxic shock syndrome no longer gets top priority.

One woman in 100 harbors the same staph strain that spawns toxic shock. Most women apparently develop protective antibodies that defend them from the poison the germs produce. Young women are apparently most vulnerable because they have not developed the antibodies. But any woman, it seems, can become more vulnerable when she uses a tampon, especially a high-absorbency tampon.

There are many possible scenarios for what may happen in toxic shock. Blood and menstrual fluid are good culture media for bacteria. The staph germs thrive in a warm environment. The mucous membrane of a woman's reproductive organs also may prevent the body's protective white cells from attacking.

Add a barrier, a tampon, and more blood and menstrual fluid are trapped as growth media. The crucial added element, said Minnesota's Dr. Schlievert, may be trapped oxygen. The greater the tampon's absorbency and the more closely it fits, the more trapped blood and oxygen to support bacterial growth.

First Schlievert and then Dr. Merlin Bergdoll of the University of Wisconsin independently isolated what they say they think is the bacteria's principal toxin. They say they hope to produce both a blood test for the disease and an antitoxin.

Most toxic shock patients recover. Some victims have permanent nerve or other damage. In a few cases victims have had toes or fingers amputated where loss of blood flow caused gangrene. Some women have had as many as five or six repeat attacks.

Debbie Headlee, after a second attack a month after her first, said, "I would never use a tampon again." Most women still like tampons, however. The two women doctors most closely involved with the CDC investigation still use tampons. One disgusted woman telephoned the CDC in 1980 to say, "I know why this happened. They finally found a tampon that worked."

Starting last Dec. 20, the Food and Drug Administration ordered tampon makers to put a toxic shock warning either on or inside tampon packages. The warning must suggest that a woman use tampons with the least absorbency needed.

Yet there is no way for a woman to know which brands are most or least absorbent, and products as absorbent as Rely Supers are still being sold, Osterholm reports. Most manufacturers sell several varieties, ranging from "super-plus," for example, to "super" to "regular." But the terms have no standard meaning.

Osterholm studied tampons made in 1979-80. Playtex Super-Plus, o.b. Super Plus, Tampax Super Plus, Kotex Super and Playtex Super were all in the highest-absorbency group with Rely Super. In a mid-group were o.b. Super and Playtex Regular; in a somewhat lower absorbency group, Tampax Super, Kotex Regular, o.b. Regular and, least absorbent, Tampax Slender.

Since then, he said, Kotex has reduced absorbency, and another maker, whom he said he cannot name, has increased it somewhat.

Osterholm and activist women's health groups want tampon makers to disclose the measured absorbency of all brands. Negotiations are in progress, but the outcome is unsure.

Still, Osterholm said: "There is one positive aspect to all this. We're learning a lot more. Toxic shock has brought menstruation and women's health out of the closet."