a1 Formerly at the Department of Microbology Guys Hospital Medical school, UMDS, London.
The possibility that a devastating human pandemic could arise, causing massive loss of human life, is discussed. Such a major threat to the human species is likely to be a virus, and would spread by the respiratory route. It need not necessarily cause massive loss of life, but if it caused serious illness or incapacity it would still have a major impact. A possible source is from an existing respiratory pathogen, but it would more probably arise from an infection that is maintained in an arthropod or vertebrate host, but which at present either does not infect humans, or if it does it fails to be effectively transmitted between them. More research should therefore focus on the pathogenetic factors and the viral determinants that promote respiratory transmission.
p1 Present address: Sheriff House, Hammingden Lane, Ardingly, Sussex RH17 6SR. UK.