SARS Virus Found in Tears
Could Mean Earlier Diagnosis, Earlier Pinpointing of Source of Spread
June 21, 2004 -- The highly contagious SARS virus has been found in human tears, a new study shows. This means that the infection may spread through contact with tears -- and that tear analysis could help with diagnosing the infection, researchers say.
Last year, SARS -- or severe acute respiratory syndrome -- had a significant worldwide impact, both in human deaths and the world economy. Singapore was one of the countries affected by SARS, writes lead researcher Seng Choo Loon, MD, with the Eye Institute of National University Hospital in Singapore. His study appears in the current issue of the British Journal of Ophthalmology.
In a preliminary effort to identify patients early when the epidemic first broke, Loon and his colleagues collected specimens from various secretions, including tears, from patients diagnosed with SARS. Laboratory testing showed that the virus was indeed in the tears -- as has been reported with other viruses, he explains.
"Finding the SARS virus in tears is important, as the latter may be a potential source of spread," he writes. "This is the first recorded [evidence] of detection of the SARS virus from tears."
His current report is of 36 people suspected as having SARS, including 17 health-care workers. Loon and his colleagues analyzed their tear samples in a laboratory; tears from three people tested positive for SARS. Two were elderly patients who died from SARS; the third was a young, female health-care worker who recovered from the infection.
All three positive tear samples were taken in the early stages of infection, he adds. Samples from five other probable cases, which were taken in later stages of infection, tested negative.
"The ability to detect and isolate the virus in the early phase of the disease may be an important diagnostic tool for future patients," Loon writes. "Tear sampling is both simple and easily repeatable."
His study also helps explain risks to health-care workers who may catch the virus from their patients since they are in close proximity with them, he says. Use masks, gowns, gloves, and goggles when dealing with suspected SARS cases, he advises.
In the eye doctor's office, all sorts of equipment like trial frames and reusable pinhole testing devices, and even the doctor's hands can spread the infection among patients, Loon says.
After all, SARS is not likely dead. "Even as the epidemic has died down, we are warned of future outbreaks," he says.