• infectious diseases

In developed countries, infectious diseases (ID) fully dominated the population health problems until the first decades of the past century, and continue in poorest countries today. Epidemics like plague or cholera, at different times, have killed significant proportions of the population from important cities, including European ones. The decline of ID in the 19th century, raised, in scientific circles, the belief that they would disappear and that their persistence in poor countries would also diminish following the tendency observed in developed countries. A world without ID was announced. The most complete formulation of this idea is the so called epidemiological transition theory.¹ However, the unexpected happened: over the last decades of the 20th century ID emergence/re-emergence was registered, even in the rich parts of the world. In the poorest parts the new diseases have added to already large ID burden.²

Historical studies bring us some enlightenment. A historian analysing the importance of this group of diseases in the history of human society made some surprising observations.³ He criticised the dominant notion that ID had not had an important influence …