thanks to everyone that answered. That was exactly what his wife told me, but since then he has had a lumbar puncture and they have found that staphylococcus that normally lives quite happily outside your body has somehow got inside and has affected his stem cells, this will be treated with antibiotics. So now we know! But it sounded really serious when we first heard. Thanks again!
will know more in 5 days times, when the results are through. At the moment he isn't on any medication whatsoever, just trying to recover from a very painful back due to the lumbar injections (he had three!)