------------------------------------------------------------- DISEASE NO. + ++ +++ POSITIVE NEGATIVE ------------------------------------------------------------- Measles 47 10 6 12 28 19 Infectious arthritis 38 9 6 4 19 19 Pneumonia 30 5 8 5 18 12 Typhoid 27 6 8 3 17 10 Scarlet fever 10 0 0 4 4 6 Smallpox 14 1 4 0 5 9 Miscellaneous 12 2 5 2 9 3 ------------------------------------------------------------- 178 33 37 30 100 78 ------------------------------------------------------------- [14] Warfield, L. M.: Jour. Lab. and Clin. Med., November, 1917. A summary of the cases showed: 252 cases without sclerosis; 248 with sclerosis; 147 cases with infections but no sclerosis; 180 cases with infections and sclerosis. This study failed to throw any positive light on the question. Infectious diseases undoubtedly play a certain rôle, particularly those continuing a long time and certain particular infectious diseases, as measles. =Syphilis= Syphilis is one of the most important of the etiologic factors in the production of arteriosclerosis. It has been shown that in 85 per cent of cases of aortic insufficiency in persons, usually males, over forty-five years, who did not have chronic infective endocarditis, the Wassermann reaction was positive. Acute aortitis affecting the ascending and transverse portions of the arch of the aorta is very commonly seen, and the irregular, scattered, slightly raised, yellowish-white patches of sclerosis in the arch which are found years after the syphilitic lesion, are considered by some to be very characteristic of syphilis. Mesaortitis is the primary lesion and acts as a _locus minoris resistentiæ_ where an aneurysm forms. Hypertensive cardiovascular cases have been serologically studied, and a positive Wassermann reaction found in a large percentage of one series. In fifty cases, 90 per cent either gave a positive Wassermann reaction or luetin test, were known to have syphilis, or had children with hereditary syphilis. This suggests what might be called "familial cardiovascular syphilis." Hypertensive disease is possibly one of the common so-called "late" manifestations of syphilis. That syphilis is responsible for the arterial disease in the vessels of the brain, resulting in apoplexy or sudden cardiac death in middle life, has long been known. In fact, it is claimed (Osler) that all aneurysms occurring in persons under thirty years of age are due to syphilitic aortitis. In the late stages of syphilis the arterial lesions may be of a diffuse character. =Chronic Drug Intoxications=