Scientists have determined the geographical center and time frame for the emergence of HIV

Scientists say that the reason for the rapid spread of immunodeficiency virus in the human population, which became a real pandemic, which infected more than 75 million people worldwide, was the “perfect combination” of factors that came together in colonial Africa at the beginning of the last century.

Genetic analysis of several thousand individual viruses confirmed that, without any doubt, HIV first appeared in Kinshasa, the capital of the Republic of Congo, around 1920, where it spread through the colonial railway network to other parts of central Africa.

Scientists believe that their new discovery has finally narrowed the initial spread of HIV to a single source, the colonial-era city of Leopoldville (the old name of Kinshasa), which later became the largest city in Central Africa focused on trade, including the sale of meat from forest game caught in nearby forests.

In a new study, based on the analysis of subtle genetic differences between different HIV subtypes, it was determined that people developed HIV from a virus infecting monkeys, which, in turn, were hunted for food and which they subsequently very likely brought with them to Kinshasa.

Rapid social change, the development of prostitution, the reuse of medical syringes and many other factors contributed to the rapid spread of the virus to more distant distances in the Congo by millions of passengers who used the local railway network daily, scientists say.

“For the first time, we were able to analyze all possible evidence thanks to the latest phylogeographic research methods that allowed us to statistically identify where this virus came from,” says Oxford University professor Oliver Pibus, lead author of the study published in the latest issue of the journal Science.

“In other words, it means that we are very likely to know where and when the HIV pandemic started. It seems that a combination of factors in Kinshasa in the early 20th century created the “ideal conditions” for the rapid spread of HIV, leading to a generalized and unstoppable epidemic that hit all of Central Africa.

In earlier studies, scientists also assumed that HIV was originally transmitted to humans from monkeys, and then developed into a pandemic, the center of which was Central Africa in the first half of the last century. However, a new study based on all the collected facts was able to more accurately determine the time and geographical scope of the epicenter. This epicenter in 1920 was the city of Kinshasa.

“Based on spatial information, we were able to learn where the virus appeared and how it spread, which became a powerful pandemic. By this time, the city of Kinshasa was developing very rapidly. It was the largest city in Central Africa and was very well connected to the rest of Congo, said Dr Nuno Faria of Oxford and one of the participants in the new study.

“Information from the colonial archives told us that by the end of the 1940s more than one million people had travelled through Kinshasa every year. Our genetic information about the virus suggests that HIV has spread very quickly through the Democratic Republic of Congo, a country the size of Western Europe, says Dr Faria.

Further social changes in the country, leading to independence in 1960, helped the virus break down the barrier between small groups of infected people and penetrate the wider population. The virus was also transmitted to Haitian immigrant workers, who then brought it to their homes, where it was later transmitted to U.S. tourists.

“Our study also showed that initial transmission of the virus from animals to humans, possibly as part of hunting or processing wild animal meat, covered a very limited time frame during the Belgian colonial era, if we are talking about a specific strain of HIV, which subsequently spread and developed into a real pandemic,” adds Professor Pibus.

“By the 1960s, the development of transportation systems, the same railways that initially contributed to the widespread spread of the virus, had become less active, but by that time signs of a pandemic had spread across Africa and beyond.”

“Previous studies have suggested that initial transmission of the HIV virus from monkeys to humans may have occurred in the southeastern parts of Cameroon, near the borders of the Belgian Congo,” Dr Faria said.

Source: hi-news.ru