Sandy Schmidt, 42, came down with the mysterious illness soon after she ran a marathon in San Francisco last July. She got better before becoming sick again this spring, forcing her to quit her job as a business office manager. Running even one mile now would "put me in bed for a day and a half," she said.
Schmidt is among 160 residents of Lake Tahoe's North Shore who have been diagnosed by two local physicians since the winter of 1985 as having a chronic flu-like illness in a medical puzzle that has assumed national proportions.
Most of the victims are well-educated, previously healthy, about 40 years old and are more likely to be women than men. Their complaints also are similar: severe fatigue, recurrent colds and difficulties with memory and concentration. About half of them have enlarged lymph nodes in their neck and almost all have abnormal blood tests, suggesting that a common viral infection may be involved.
Drs. Peter R. Cheney and Daniel L. Peterson believe the explanation may be a chronic version of the familiar Epstein-Barr virus, which causes mononucleosis. But the so-called "kissing disease" affects primarily children and young adults, albeit the short-lived symptoms are not unlike those being seen here.
If they are right, solving the puzzle of this cluster of illnesses may have wide repercussions. Perhaps tens of thousands of Americans throughout the country with chronic lethargy have been similarly diagnosed in recent years as suffering from chronic infection with the Epstein-Barr virus. And many of them have joined support groups or sought unproven treatments with antiviral or other drugs.
But there is sharp disagreement over whether the Epstein-Barr virus explains more than a handful of cases of chronic illness nationwide--or any of the cases in this area. Indeed one Incline Village physician has accused the two doctors who have been making the local diagnoses of "perpetrating a hoax."
And last fall, two investigators from the federal Centers for Disease Control spent several weeks here looking into the mystery. They concluded last week that they could "neither prove nor disprove" the relationship between the Tahoe illnesses and the Epstein-Barr virus.
That finding was immediately questioned by Dr. Paul R. Cheney, one of the two doctors who has been treating the patients. He said the investigation was too narrow and has been overtaken by subsequent developments.
"Something unusual happened there," agreed Dr. Anthony Komaroff, chief of general medicine at the Brigham and Women's Hospital at Harvard Medical School. He is collaborating with Cheney in an ongoing research study. "It is not all fabrication or hysteria or misinterpretation. I have guesses, but it is still a mystery."
The Tahoe cases are puzzling because the mononucleosis virus, which spreads through the saliva, is not easily transmitted and has never been known to cause an epidemic. (The Lake Tahoe illnesses are not related to an outbreak of a respiratory virus in Los Angeles last winter that affected some nursing home residents.)
Conceivably, a new strain of the virus has developed. Or another infectious agent may be the culprit, and the Epstein-Barr virus may not even be responsible.
The fact is, doctors cannot even agree how to define this infection, recognize it and treat it.
Better Blood Tests
The current controversy is likely to continue until better blood tests are developed--perhaps in the next several years--because the current tests often give ambiguous results. Since 1968, the Epstein-Barr virus has been linked to mononucleosis, whose symptoms include fever, sore throat and enlargement of the lymph nodes and spleen. It usually runs its course in several weeks.
By the age of 60, four-fifths of Americans have had an infection with the virus, often through contaminated eating and drinking utensils. But the vast majority either never had symptoms to begin with or recovered completely. Infected individuals become lifelong carriers of the Epstein-Barr virus.
Like other members of the herpes virus family, this virus can be periodically reactivated, for unknown reasons, leading to, for example, some forms of nose and throat cancer, Burkitt's lymphoma, a tumor of the lymph glands that is common in Africa and a variety of severe illnesses in patients with abnormal immune systems.
When Cheney and his partner, Dr. Daniel L. Peterson, both internal medicine specialists, saw their first patients with severe fatigue in the winter of 1985, they were "not all that impressed," Cheney recalled. They thought the patients would recover quickly, without requiring special laboratory investigations or treatments. But every couple weeks, they saw a few more cases.
By May and June, many of the first patients were still not better, and the doctors were diagnosing up to 15 new cases a week, including 10 cases among teachers at one high school and five cases among teachers at another.
Many of the patients had first seen other physicians who either "didn't know what was going on or thought the patients were crazy," according to Cheney.
'Nightmare That Wouldn't End'
"We were horrified," Cheney recalled. "We felt like we were in a nightmare that wouldn't end."
The patients were mostly year-round residents of Incline Village, Tahoe City and Truckee, communities with a combined population of about 30,000. One victim, a teacher in her early 50s who has been unable to work since September, recalled last week: "My days are pretty boring. I read or get a videocassette. I feel like a Raggedy Ann with no stuffing."
About 15% of the 160 patients are as ill today as when they were first diagnosed, about 60% have waxing and waning symptoms, and about 25% feel they have recovered. No new cases have been added to the outbreak since January. About 100 cases of an apparently similar illness were also reported in the isolated farming community of Yerington, Nev., about 50 miles to the southeast.
In the early spring of last year, Cheney and Peterson studied two articles in the January, 1985, Annals of Internal Medicine, which cited the possible role of the Epstein-Barr virus in such patients.
They ordered blood tests for their patients, speculating that the tests might help solve the riddle. They were "astounded" when test after test showed high levels of antibodies to the virus. Blood tests for other diseases were usually negative.
Last summer, Cheney, 38, who also has a Ph.D. in physics, requested help from the the Centers for Disease Control, where he had done immunology research as a medical student.
After studying 15 chronic fatigue cases by reviewing medical charts and conducting interviews, Drs. Gary Holmes and Jon Kaplan of the Centers for Disease Control found that many patients had "non-specific symptoms" and many of their test results were similar to test results of a control group of healthy patients.
In the centers' Morbidity and Mortality Weekly Report, the federal agency advised doctors nationwide to search first for the other "definable" and perhaps "treatable" diseases in patients with severe lethargy, such as anemia, tumors, anxiety or depression. "It was really hard to make any definite statements," Holmes said in a telephone interview from the centers' headquarters in Atlanta. The agency plans no further studies.
But Cheney said that, after Holmes and Kaplan left, additional evidence has emerged to incriminate the Epstein-Barr virus or a related pathogen.
Another four patients developed the fatigue malady, and two are still ill months later. By chance, they all had blood tests before they became sick, and the tests showed they had not been exposed to the virus, Cheney said. Subsequent test results suggested exposure to the virus. Two of the patients, it turned out, had been in the control group of healthy people for the Centers for Disease Control study.
Some chronic fatigue patients have had brain abnormalities identified on "magnetic resonance image" scans, according to Cheney. Others have been tested for subtle immune system abnormalities.
Sheila Bastien, a neuropsychologist from Berkeley, found significant memory and concentration problems in eight patients she tested, including a teacher, a nurse and a business owner. "Many of these individuals are far too . . . impaired to function effectively," she concluded in a report sent to Cheney last month.
Academic Study Under Way
Such data is being studied by Komaroff of the Harvard Medical School and collaborators at some of the nation's leading medical schools, including Harvard, Duke University and the University of Massachusetts. "We are helping a small private practice conduct an academic study of a phenomenon that has fallen upon them," he said.
Cheney has cut back his practice time by 25% and run up phone bills of $2,000 a month in order to research the mysterious cluster of cases. While he believes that the Epstein-Barr virus is a "common denominator," he acknowledged that the definitive answer is still elusive.
The Tahoe puzzle underscores a more general philosophical disagreement in modern medicine between physicians who are willing to diagnose and treat patients primarily on the basis of their complaints and the results of an examination, and those who insist on unequivocal laboratory proof of the relationship between abnormalities and an illness.
Doctors in the latter group point out, for instance, that some labels used in the past to explain chronic fatigue, such as "neuromyasthenia" or "hypoglycemia," were widely discredited after more data was gathered.
Even the principal authors of the two articles in the Annals of Internal Medicine that sparked the current interest in Epstein-Barr virus disease disagree on its significance. "There are many causes of chronic fatigue . . . (but) the data regarding Epstein-Barr virus are very, very weak," said Dr. Stephen E. Straus, chief of the medical virology section at the National Institute of Allergy and Infectious Diseases. "It is still very much a research issue."
In contrast, Dr. James F. Jones of the National Jewish Hospital and Reseach Center in Denver and the author of the second article, said he has seen "several hundred" patients who he believes have the disease. "The illness exists. There is a very clear picture. The patients can't go to work or school. Their marriages break up. All aspects of life are interfered with."
Jones cautioned, however, that the diagnosis should not even be considered until individuals had been sick for at least two years, a definition that would exclude many patients who have been diagnosed with the disease, at least for now.