In the UK you not meant to operate heavy equipment and the like for 24 hours and I seem to remember that they have a 48 hours before flying commercially somewhere in the rule book. But thats slightly different and I think its to give your body a chance to build up the red blood cells again for flying at altitude with pressurisation and the chance of failure.
I spent a month in South America and that put a stop to any blood donation for me. Exposure to some spider and a tick puts me into a high risk group.