Dating epidemic

Rated 4.18/5 based on 519 customer reviews

However, the types of apes shown to carry the SIV virus are different in South America.

The primary point of entry, according to researchers, is somewhere in the jungles of Brazil.

The discovery of the main HIV / SIV phylogenetic relationships permits explaining broad HIV biogeography: the early centres of the HIV-1 groups were in Central Africa, where the primate reservoirs of the related SIVcpz and SIVgor viruses (chimpanzees and gorillas) exist; similarly, the HIV-2 groups had their centres in West Africa, where sooty mangabeys, which harbour the related SIVsmm virus, exist.The pandemic HIV-1 strain (group M or Main) and a rare strain found only in a few Cameroonian people (group N) are clearly derived from SIVcpz strains endemic in Pan troglodytes troglodytes chimpanzee populations living in Cameroon.Thus, this region is presumably where the virus was first transmitted from chimpanzees to humans.However, reviews of the epidemiological evidence of early HIV-1 infection in stored blood samples, and of old cases of AIDS in Central Africa, have led many scientists to believe that HIV-1 group M early human centre was probably not in Cameroon, but rather further south in the Democratic Republic of the Congo, more probably in its capital city, Kinshasa (formerly Léopoldville).Using HIV-1 sequences preserved in human biological samples along with estimates of viral mutation rates, scientists calculate that the jump from chimpanzee to human probably happened during the late 19th or early 20th century, a time of rapid urbanisation and colonisation in equatorial Africa. Some molecular dating studies suggest that HIV-1 group M had its most recent common ancestor (MRCA) (that is, started to spread in the human population) in the early 20th century, probably between 19.

Leave a Reply