Quantitative temporal-spatial distribution of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) in post-mortem tissues.

Few post-mortem studies have been performed on patients who have died from severe acute respiratory syndrome (SARS). No studies have examined how the SARS-associated coronavirus (SARS-CoV) loads in different organs with respect to time, post-mortem. The aim of this study was to determine the quantitative temporal-spatial distribution of SARS-CoV in the post-mortem tissue samples of seven patients. Quantitation of a house-keeping gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was undertaken to standardize the amount of tissue tested. SARS-CoV viral load and SARS-CoV/GAPDH RNA ratio for each organ type were related to four time durations: onset of illness to death, death to post-mortem tissue sampling, and total durations of treatment with ribavirin and hydrocortisone. The SARS-CoV/GAPDH RNA ratio remained relatively stable in most organ tissue types for all these time durations. The ratio reached the highest value of equal to or greater than one for lung and small bowel, whereas those for heart, liver, spleen, and kidney were always less than one. It is concluded that SARS-CoV viral loads in these organs remain relatively stable, post-mortem. This quantitative assessment further supports SARS-CoV has a specific tropism for the human respiratory and gastrointestinal tracts, which may be related to the density of SARS-CoV receptors.