DURING the late summer and early fall of 1947, an epidemic acute febrile illness characterized by headache, pyrexia and paroxysmal pain in the region of the diaphragm occurred in Massachusetts. Clinically it closely resembled a malady first described in Iceland by Finsen1in 1856, who called it "pleurodynia." The same syndrome has since been variously designated as "Bornholm disease," "epidemic muscular rheumatism," "acute benign dry pleurisy," "epidemic pleuritic pain," "Bamle disease" and "devil's grip." The last name was based on the description of the pain in the chest experienced by one of Dabney's2patients in the first outbreak reported from the United States. The literature on the disease was reviewed by Sylvest3in 1934 and has been brought up to date by Scadding.4 The etiology remains obscure. Small5found inclusion bodies in the erythrocytes in 2 cases, which induced him and Torrey6to believe that the disease was caused by a