In a recent study, to be published in tomorrow's issue of the journal Nature, scientists reveal new interesting facts about a virus and a disease which have killed so many people, but still remain more of a mystery.

Their recent findings show that the Human Immunodeficiency Virus has been around for more than we initially thought, placing the first HIV outbreak between 1884 and 1924, with a more focused estimate at 1908.The previous estimate indicated that the virus first appeared in the 1930s, but latest tests on infected tissue prove them wrong.

A team of scientists from the University of Arizona at Tucson have analyzed two of the earliest samples of the virus ever found, a 1960 sample of HIV gene fragments from a wax-embedded lymph-node tissue biopsy from a woman with HIV-1 group M genetic sequence and a 1959 blood sample from a man, both from Kinshasa, in the Democratic Republic of the Congo, formerly known as Leopoldville, capital of Belgian Congo.

The two people seem to have a common ancestor dating from at least 50 years earlier, the scientist say, after analyzing the genetic differences between the two viruses, and calculating the amount of time these differences would take to evolve. The virus might have been transmitted by that ancestor to his family members, but the “founder event” of the original infection may have involved eating monkeys infected with a similar virus.

Dr Michael Worobey, who led the research, said: "Now, for the first time, we have been able to compare two relatively ancient HIV strains. That helped us to calibrate how quickly the virus evolved and make some really robust inferences about when it crossed into humans, how the epidemic grew from that time, and what factors allowed the virus to enter and become a successful human pathogen.”

The study also generated a theory regarding the spreading of HIV and its development into AIDS, a disease that became one of the world’s most feared and common plague. It is believed that the urbanization of colonial Africa, principally the present-day city of Kinshasa in the Democratic Republic of the Congo, where the two samples of tissue were found, is the reason for the quick spreading of the virus.

Constantly growing cities opened a door to high-risk behaviors, like prostitution, and the increased number of people living together in a new society only made it easier for the virus to spread, first in small communities, then all around the world.

AIDS was first recognized formally in 1981, when it became a much-talked-about subject, but with all the research and efforts to prevent or cure the disease, millions of people across the globe are still affected by the life-threatening virus.

But Dr. Worobey thinks that the results of his recent study is not only going to help finding the source of the Human Immunodeficiency Virus, but might also help finding a cure or, at least, better ways of prevention:"I think the picture that has emerged here, where changes the human population experienced may have opened the door to the spread of HIV, is a good reminder that we can make changes now that could help reverse the epidemic. If HIV has one weak spot, it is that it is a relatively poorly transmitted virus. From better testing and prevention, to wider use of the antiretroviral drug therapy, there are a number of ways to reduce transmission and force this virus back into extinction.”