I am glad I never joined the Communist Party in Cuba, because it seems that like membership in a gang, once you’re in you never get out.
This article in the Miami Herald gives a pretty good overview of the issue in English. Basically what’s happening is that a growing number of party members are giving up their membership. In order to satisfy the party requirements they are giving various reasons, such as disease, old age, and so on, as excuses to be allowed to leave the party.
Faced with a dwindling membership the party is tightening the screws, and now warns party members that even if they are old and sick, they can still be useful to the party, so that’s no excuse to quit. In an apparent nod to Fidel’s deteriorating condition they even add this bit:
“Es necesario reiterar que la enfermedad no es un motivo de desactivación, en tanto no se trate de una dolencia que prive al militante de sus facultades mentales, lo que no incluye la demencia senil.”
Translated:
"It is necessary to reiterate that disease is not a cause for deactivation, so long as it is not an ailment that deprives the militant of his mental faculties, which does not include senile dementia.‘’
In other word you can leave if you’re crazy, but not if you’re old and crazy.
If you want to wade through the whole document in a Spanish pdf, here it is.