[Hypotheses on the role of the prehistoric Sahara in the spread of parasitic and hematologic diseases].

15,000 years ago, the Sahara was moist, inhabited by tropical fauna and travelled over by nomadic populations. Later, the dryness incited human migrations to North or West Africa. African bilharziasis (S. mansoni and S. haematobium) could have been carried by nomadic populations infected in the Nile River. Sickle cell disease and alpha-thalassemia are derived from Saudi Arabia (unless in the case of alpha-thalassemia there was an identical mutation in several regions). Echinococcosis was brought with the dromedary in the ptolemaic era whereas ankylostomiasis was brought by the Romans or the Arabs.