8 including the three africans i had in a hospital tank for you - and all within the last 12 months. i have never had any fish die this way in the 4 years i've been keeping fish prior to this last year. 
 
as for the fish that don't die - TB has carriers which are generally unaffected by the disease, as do many other diseases. 
 
i am stunned at the attitude of some on here for what is quite a scary issue. imagine, if it is actually a new, strange, unidentified disease, and instead of dealing with it, we ignore it... it could spread to every tank in NZ in a matter of a few years.... could even spread to humans....