 In the summer of 1947, at the age of 28, Ritsema contracted poliomyelitis, a condition which entailed, in his case, diaphragm paralysis and which brought him to the threshold of death.Although he survived, the disease left him paralysed from the waist down.The following winter, at the suggestion of a neurologist who had recommended a warmer climate, the Ritsemas spent a month on the shores of Lake Maggiore, near Ascona in Switzerland, where Alwine von Keller had taken up residence at the Casa Shanti