Severe Acute Respiratory Syndrome (SARS) virus has been found in tears, a discovery that poses a major challenge for health workers, according to a Singaporean study published on Monday.
Tear samples were taken from the tear ducts of 36 patients who came to Singapore's Tan Tock Seng hospital with suspected Sars in April 2003.
Eight of these patients subsequently turned out to have Sars. And in three of those eight cases, the Sars virus was found in the tear samples.
The study, published in the British Journal of Ophthalmology, was headed by Seng Chee Loon of National University Hospital, Singapore.
The researchers say the discovery opens up another exciting tool for detecting Sars in its early stages.
But, they say, it also has worrying implications for eye doctors.
"Many healthcare workers are in close proximity to the eyes of patients and this may be a source of spread among healthcare workers and inoculating patients."
That means ophthalmologists and other workers should consider beefing up their protective gear when they are treating patients suspected to have the virus.
The pneumonia-like illness claimed around 800 lives from 8,000 cases in 32 countries last year.
China - excluding Hong Kong and Taiwan - was the worst hit with 349 deaths. In Singapore, there were 33 deaths out of 238 infections.
Last month, Chinese scientists announced that the Sars corona-virus had been found in sweat glands and the intestine, raising fears that the disease may spread via contaminated sewage, food or even a handshake.
The typical path of transmission is through airborne droplets, expelled by coughs or sneezes, that are inhaled by someone in close proximity.