RESUMEN
It is generally accepted that human immunodeficiency virus (HIV) is the etiological agent of acquired immune deficiency syndrome. According to this claim, HIV was transferred to humans from contact with monkeys around 35-50 years ago. However, this claim has not been sufficiently confirmed epidemiologically. The spread and incubation period of the plague epidemic has led to the theory that the Black Death was caused by hemorrhagic viruses. Having examined detailed historical data, we have concluded that the bacterium Yersenia pestis was an infectious agent in the epidemic, together with another agent which we suggest was HIV. Our considerations were mainly based on the existence of the CCR5 delta 32 mutation, which protects against HIV infection and has been present in the Caucasian population for over 2000 years. The combination of two infectious agents led to the devastation of the Black Death, the removal of HIV carriers, and an increase in the number of CCR5Δ32 mutations in the Caucasian population. In sub-Saharan Africa, this epidemic and subsequent sanitation process did not occur, which explains the much higher level of HIV genetic information in this part of the world.