Sars may 'spread via touch'
2004-05-07 09:11
Paris - The Sars virus has been found in sweat glands and the intestine, according to a new study, which says that in theory the disease may spread via contaminated sewage, food or even a handshake, not just by airborne droplets.
Pathologists from the First Military Medical University in Guangzhou, southern China, warn that if further research proves that the disease can be transmitted by these unexpected routes, the implications for public health are major.
The team devised two methods of testing for the presence of the coronavirus (Sars-CoV).
One was an antibody that binds specifically to the virus, and the other was amplification of telltale fragments of viral DNA.
Using these two markers, they tested tissue that had been taken from four people who had died of Sars, and from four "controls", people who had died of other causes.
The results were remarkable, according to their study, which is published on Friday in a British peer-reviewed publication, the Journal of Pathology.
As expected, they found that the lungs of Sars victims to be riddled with the virus: up to 49% of the tissue cells they viewed had been infected.
This is unsurprising because Sars is already known to be a disease that can be carried by droplets expelled in sneezes and coughs, its prime target area is the airways, and its symptoms are akin to pneumonia.
"Strikingly," the authors add, "Sars-CoV was also detected in many other organs and tissues, including stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal, liver and cerebrum (brain)."
'Primary target'
Viral infection in the small intestine and renal system reached from 25 to 49% of cells, and the same figure was seen for the skin. In the liver, pancreas and brain, 24% or less of cells were infected.
Lead researcher Ding Yangqing said that, like the respiratory tract, the gastro-intestinal system could be "a primary target" for the virus.
"This suggests that the gastro-intestinal system may also be an entry route for Sars-CoV (if it is) present in food or water.
"Although there is no report of such transmission, caution should be exercised by the at-risk population during the Sars-CoV endemic season. This finding supports the hypothesis that Sars-CoV may be released into the environment via faeces from individuals" with the disease.
As viral traces were found in the kidneys, urine may also theoretically transmit the disease.
Ding also noted that the virus had, for the first time, been found in sweat gland cells in the skin.
"This suggests another route of transmission for Sars-CoV, since this virus may be excreted in sweat and infect other people who are in direct contact with the patient's skin."
If skin contact is confirmed as a transmission route, it would mean that patients may have to wear gloves, disposable gowns and eye goggles, in addition to a face mask, to avoid kissing or touching other people.