The disease that carried Mozart off 224 years ago today was as sudden as it was mysterious. It struck during a year in which he was uncommonly healthy and also spectacularly productive. Only its essential elements are known, the most striking of which was progressive swelling (i.e., edema) of the entire body, ultimately so profound that a few days before Mozart died he was unable to make the smallest movement and had to be fitted with a gown that opened at the back to facilitate changing. By then, according to his son, Carl Thomas, he also had a stench so awful (likely due to retained urinary waste products), that “an autopsy was rendered impossible.” Although Mozart was the disorder’s most notable victim, he was by no means its only one. According to Dr. Eduard Vincent Guldener von Lobes, one of several consulting physicians: “A great number of inhabitants of Vienna were at this time laboring under the same complaint, and the number of cases which terminated fatally, like that of Mozart’s, was considerable. I saw the body after death, and it exhibited no appearances beyond those usual in such cases.” Von Lobes’ statement was recently confirmed by Zeger, Weigl and Steptoe, who found a marked increase in “deaths from edema among young men” recorded in Vienna’s official daily register in the weeks surrounding Mozart’s death compared with previous and following years.
Although over 100 different diagnoses have been proposed as the cause of Mozart’s fatal illness, none fits its character, course, and epidemiological characteristics better than acute glomerulonephritis – acute inflammation of the microscopic filters of the kidneys (the glomeruli) induced by a preceding streptococcal infection. Mozart, in fact, was no stranger to streptococcal infections and their complications. He had a series of severe illnesses as a child, which were almost certainly recurrent episodes of strep throat and streptococcus-induced acute rheumatic fever. Therefore, if his final, fatal illness was acute, post-streptococcal glomerulonephritis, it would have been just one of many times his life could have been cut short by an encounter with streptococci. However, unlike acute rheumatic fever, post-streptococcal glomerulonephritis is typically a benign disorder of young children, which virtually always resolves fully in a matter of weeks. How then, could acute, post-streptococcal glomerulonephritis explain not just Mozart’s death, but also those of the many other young Viennese men who died of “edema” during the winter of 1791/2?
The answer lies with the particular species of streptococcus responsible for the cases of acute glomerulonephritis. Streptococcus pyogenes is the species of streptococcus responsible for the vast majority of acute post-streptococcal glomerulonephritis (also “strep throat’ and rheumatic fever) – those benign cases, involving children who recover completely after relatively brief illnesses. There is, however, another rarer form of post-streptococcal glomerulonephritis, a much severer form, which attacks and sometimes kills adults. It’s caused by a different species of streptococcus, Streptococcus equi, the agent responsible for “strangles,” a highly contagious infection of horses. The bacterium also attacks cows, and in rare instances in which humans are infected, consumption of milk or milk products from S. equi-infected cows is responsible. The infection produces an illness typical of acute glomerulonephritis, in which over 90% of the victims are adults. One in 50 dies, even with the best care available today. One in 20 requires renal dialysis to recover, which, of course, was not available in Mozart’s day.
In the final analysis, of the myriad diagnoses proposed to date, only an epidemic of acute post-streptococcal glomerulonephritis caused by milk or cheese contaminated with S. equi, explains both the clinical and the epidemiological features of Mozart’s fatal illness.
Headline image credit: Mozart family portrait, circa 1780. Public domain via Wikimedia Commons.