Medical detectives have found that a young man died of hantavirus infection in San Francisco 13 years before the famous "Four Corners" outbreak in the Southwest.
The discovery supports a growing sense that the disease is not a new killer but has instead existed undetected for many years.The 22-year-old man, whose name is withheld by researchers for confidentiality reasons, sickened and died in 1980 while visiting his mother in San Francisco on a hitchhiking trip from New Mexico.
For years, his mother was troubled by the unresolved death. In 1993, she asked for a new examination of stored samples of her son's lung tissue.
"What it says to all of us who looked at it is that it isn't a new disease - just newly recognized. It's been around for a while," said Dr. Sandra Schwarcz of the San Francisco Health Department.
"The nicest part was when I told his mother," said Schwarcz. "It provided her with closure."
Hantavirus was unheard of before a sudden outbreak of respiratory failure and death in a cluster of young adults in the southwestern United States in May 1993. Lab evidence linked the outbreak to a previously unrecognized hantavirus, called Sin Nombre virus.
Since then, the disease has been found elsewhere in the country, demonstrating a wider distribution than first thought.
Federal authorities report that 131 other cases of hantavirus infection have been recognized in 24 states. The largest number has occurred in New Mexico, with 28 cases, and Arizona, with 21 cases. Cases also have been confirmed in Argentina, Brazil and Canada.
California has had 13 cases, eight fatal, according to the state Department of Health Services. Its victims include an Oakland psychologist, a Portola equestrienne, a UC-San Diego biology student and a Santa Barbara ranch hand.
The virus is carried by the tiny deer mouse, the most common and widespread of the white-footed mice native to wooded areas of the western United States.
The Four Corners outbreak, which brought the disease to medical attention, has since been linked to huge rains, an abundant crop of pine seeds and a subsequent tenfold jump in the mouse population. Without such a large outbreak, it might still be undetected.
The new report, published in the latest issue of the Western Journal of Medicine, describes one of the oldest known cases of the disease. A similar study from Michigan authorities, published in the British journal Lancet last year, traced the disease to 1978.
These retrospective diagnoses provide evidence that sporadic cases of the disease are likely to have occurred for many years, at an unknown frequency, but were undetectable until the advent of new analytical lab techniques.
The San Francisco story started on Feb. 28, 1980, when a young man came to a hospital clinic, suffering from severe fever, nausea and respiratory distress. He was discharged, then admitted later that night with rapidly worsening symptoms. He died shortly after of cardiac arrest.
He had arrived in the city 10 days before the onset of his illness, following a three- to six-week hitchhiking trip from New Mexico. There he lived alone in a rural adobe brick house, daily gathering wood and hunting rabbits and squirrels.
His illness was never diagnosed. His death remained unexplained. But when later news articles described an outbreak of a "new" disease called Hantavirus Pulmonary Syndrome, his mother immediately recognized the symptoms.
She recalled that pieces of his lungs had been saved by doctors. On her request, researchers retrieved these specimens, imbedded in paraffin, and sent them off to the federal Centers For Disease Control and Prevention in Atlanta for testing.
His tissue was found to be infected with the "Sin Nombre" virus.
(Distributed by Scripps Howard News Service.)