<p>Diphtheria and tetanus have been brought under control in many areas of the world through mass immunisation programmes. Consequently, they are becoming forgotten infectious diseases. As diseases gradually disappear from the general population, more people come to regard them as diseases of the past, and no longer feel the need to maintain immunity through vaccination. As vaccination levels drop, diseases that were once under control begin to reappear, sometimes resulting in severe complications that can lead to permanent injury or death.</p>