Largest post-mortem study of SARS deaths teaches scientists about the disease

Led by John Nicholls of Hong Kong University, researchers from Hong Kong and from Toronto (two of the cities worst affected by the 2003 SARS outbreak) joined forces for a large and detailed study of the bodies of 32 patients who had died from SARS.

The results, reported in the international open-access journal PLoS Medicine, suggest ways when and how treatments for this disease might be most effective.

The findings suggest that the SARS virus causes illness and death by attacking cells in the alveolar epithelium, a particular tissue that lines the lung.

The virus multiplies mostly within this group of cells, and only for a limited time after infection. Antiviral drugs are likely to be only useful during this initial time window after infection.

After less than two weeks, the body’s immune system seems to be able to fight back and prevent the virus from further multiplying, but this does not lead to recovery in all patients.

In fact, most of the patients in this study (25 out of 32) died more than two weeks after they fell ill and without signs that the SARS virus was still multiplying in their body.

This suggests that disease progression and death is not dependent on continued widespread virus multiplication but that in patients who die the initial damage to the lungs is so severe that they cannot recover.

The study also suggests that death from SARS is not due to the virus multiplying outside of the lungs.