| multiple sclerosis in key west, florida. | in 1984, a press release by a miami, florida, neurologist described a possible cluster of persons with multiple sclerosis in key west, florida. the authors examined the cluster using prevalence rates, which are recognized as having a latitudinal gradient for multiple sclerosis, being generally high at high latitudes and low at low latitudes. case ascertainment showed 32 definite or probable cases among residents of the study area (latitude, 24.5 degrees n) on september 1, 1985, a prevalence rate ... | 1989 | 2816901 |