Finding SARS-CoV virus in many parts of the body leads to calls for more stringent infection control measures

New research in two papers published this week in The Journal of Pathology gives greater insight into why the virus is so deadly, and shows that it could transfer from person to person via breath, urine, faeces and even sweat.

Searching for SARS

Scientists in China used markers that only bind to SARS-CoV to analyse tissues from four people who had died of the infection. They found the virus in the lungs, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum.

Finding the virus in sweat glands leads to the possibility that it could spread via sweat. Discovering it in the lungs, trachea and bronchi explains why it is spread by coughs and sneezes. Finding it in the intestinal tract and kidney shows that it could also be spread via faeces and urine, opening the possibility that the virus could infect a person via contaminated food or water.

“As a result of our work we recommend new infection control measures which include getting patients to wear gloves, disposable gowns, and eye protection, in addition to N95 masks, and to avoid kissing or touching other people,” says lead researcher Dr Yanqing Ding, of the Department of Pathology, the First Military Medical University, Guangzhou, China.

Receptor binding

In a separate study, Dr Inge Hamming and colleagues at the University Hospital Groningen, The Netherlands, examined various organs and tissues, looking for Angiotensin Converting Enzyme 2 (ACE2) receptors that enable SARS-CoV to bind to cells.

Publishing their work in the same edition of The Journal of Pathology, they found ACE2 receptors at several locations, but most prominent in the lungs and kidneys, the lining of the small intestine, and on cells in sweat glands. This not only shows that the virus probably enters the body at these sites, but also that SARS could spread via coughs, faeces and sweat.

They also found the receptors on the inner lining of arteries and veins in every organ they studied. This raises the question of why SARS-CoV doesn’t infect all the organs in which it binds to the blood vessels. Their suggestion is that the virus may operate like HIV, which not only has to bind to cells, but needs an additional mechanism to gain entry.

“Finding where ACE2 is expressed provides a first step in understanding how and where the virus causes the main symptoms of SARS,” say study supervisors Dr Harry van Goor and Professor Wim Timens.

SARS background

• The virus causing SARS originated from wild animals such as Himalayan palm civets.
• It first started to infect humans in the Guangdong province of China in 2003.
• Over 8000 people had SARS in 2003 and 774 died of the disease.
• While the number of cases diminished towards the end of 2003 the virus hasn’t gone away, and fresh cases of SARS have occurred in 2004.