It may be stated that there is no laboratory diagnosis for beriberi.
Prognosis
There is no disease in which one should be more conservative in making a favorable prognosis than in beriberi. A case which seems to be progressing toward recovery may suddenly develop cardiac disturbances and die in a very short time.
We now know that a change to a beriberi-preventing diet is practically curative.
The mortality rate varies in different countries and in different epidemics, so that we have death rates varying from less than 2 per cent. to those exceeding 50 per cent. In acute pernicious beriberi the prognosis is almost surely fatal.
The epidemic of beriberi which prevailed at Manila in 1882 seems to have been attended by a great mortality, this having been as high as 60% during the early part of the outbreak.
Prophylaxis and Treatment
Prophylaxis.—It must be remembered that not only is rice, from which the neuritis-preventing vitamine has been removed by excessive milling, productive of beriberi but that the same applies to other cereals which have been similarly deprived of their vitamines.
The same result may be obtained by the employment of excessive sterilization for canning.
Fresh meat is as valuable as fresh vegetables in prophylaxis but if either kind of food be subjected to excessive heat, as is the case with tinned meats, etc., they not only do not prevent beriberi but in a negative way are beriberi-producing.