So ill he could not move, Wolfgang Amadeus Mozart supposedly sang parts of his final masterpiece, "Requiem," from his deathbed. Two centuries later, the exact cause of the Austrian composer's premature death, in December 1791 at age 35, is still a mystery. 

This portrait by painter Johann Georg Edlinger, showed Mozart not long before his mysterious death in 1791. 

Theories abound. It's known that his entire body was so swollen he couldn't turn over in bed; some say jealous rivals poisoned him, while others suggest scarlet fever, tuberculosis, or lethal trichinosis from undercooked pork. 

Now, new evidence points to an altogether different conclusion: Mozart may have died from kidney damage caused by a strep infection, possibly strep throat. Health.com: Can't stop coughing? 8 causes of chronic cough 

Dr. Richard H.C. Zegers of the University of Amsterdam and his colleagues analyzed data from Vienna's death registry. Researchers had not previously analyzed the daily death registry -- begun in handwritten script in 1607 and maintained until 1920 -- for clues to Mozart's death. 

Zegers and his team looked at information for 5,011 adults who died during three consecutive winters starting in 1790, as well as eyewitness accounts of Mozart's death, according to the study published this week in Annals of Internal Medicine. 

"By looking at the patterns of death during Mozart's time and combining them with the signs and symptoms of his final disease, we have not one but two pillars on which our theory is built," said Zegers. "Although we can't be 100 percent conclusive, I'm convinced that we have come very near the exact reason he died." 
Who has been looking it over?
Dr. Richard H.C. Zegers of the University of Amsterdam and his colleagues