Using the polymerase chain reaction (PCR) technique several viruses have been demonstrated in tears; they include herpes simplex viruses 1 and 2, Epstein-Barr virus, varicella zoster virus, human herpes virus 6, hepatitis B and C viruses, measles virus, and adenovirus. Now researchers in Singapore have used PCR to detect the virus of severe acute respiratory syndrome (SARS-CoV) in the tears of patients.

Between 11 and 18 April 2003, 36 consecutive patients at the Tan Tock Seng Hospital with probable …