2. We can expect epidemics, and pandemics [37]. The world is overdue for a pandemic of influenza. In many parts of the developing world there is increasing social and demographic turbulence -- massive migration from rural regions into urban and periurban slums, usually lacking safe water supplies, adequate sanitary facilities and public health infrastructure, often aggravated by conflict and breakdown of law and order. This scenario favours epidemic and endemic diseases and increasing social unrest.