A scientific study has recently discovered a highly aggressive new strain of HIV in Cuba that progresses three times faster than most common strains of the virus.

Typically, it takes about 10 years for someone to develop full-blown AIDS from HIV. However, a study published in the journal EBioMedicine and conducted by researchers from the University of Leuven in Belgium found that several HIV-positive people living in Cuba developed AIDS within just three years.

The study also found that the new HIV strain, named CRF19, can cause patients to become ill before they are even aware that they've been infected. This leaves doctors with less time to stop the disease from spreading in someone's body.

In the study, the researchers analyzed the blood of 73 recently infected patients. Within the group, 52 already had full-blown AIDS, while 21 were only HIV-positive. The researchers then compared their blood samples to that of 22 AIDS patients with more common strains of the virus. Researchers found that patients with CRF19 had higher levels of the virus in their blood compared to those other with had more common strains.

Researchers also found that new variations of HIV form when an infected person has unprotected sex with multiple partners and are exposed to numerous strains of the virus. In effect, the different strains can combine and form a new variant of the virus.

The World Health Organization estimates that there are currently 35 million people across the globe living with HIV/AIDS, and the disease has killed nearly 40 million since the 1980s.

A study published in October 2014 traced the origins of HIV back to the early 20th century in the western region of Congo. From there, scientists say that the deadly virus spread throughout Africa over the next several decades and eventually turned into a worldwide epidemic, infecting 75 million people.

According to the Times of India, scientists have proved beyond reasonable doubt that HIV first appeared in Kinshasa, the capital of what is now known as the Democratic Republic of the Congo, around 1920. It then spread to other parts of central Africa through the emergence of social factors, including railroad expansion, sex workers and unsafe medical practices. 

Scientists say that the origin of the epidemic of AIDS spread from the region, which was then called Leopoldville, to the biggest urban center in Central Africa.