Respiratory virus infections in travellers.

THIS subject is both too large and too small for a short paper. It is too large, in that every respiratory virus infection that man is heir to can afflict travellers of one sort or another. There seems to be no special proneness to such infections in those who travel in contrast to diarrhoeal infections. This is probably because the common viruses of respiratory tract disease are very widely and uniformly distributed, to judge by the fact that antibodies against them are found in roughly the same frequency in children and adults all over the world. Thus we either have to describe all the viruses which affect non-travellers, and say that they affect travellers too, which is to say too much, or else that the infections are no different from those of non-travellers, which is too little. Instead, I think it may be interesting to consider to what extent the viruses are dependent on travellers for their dissemination and survival.