Cuba is facing a widespread and deadly epidemic of the Human Immunodeficiency Virus (HIV) that can progress into AIDS some three times faster than the most common strains of the virus. Now researchers have identified what makes this HIV different and deadlier than most.

You may not know this, but there are actually two common strains of the virus that causes AIDS, HIV-1 and HIV-2, each with their own smaller sub-types often varied by region. As of last November, these strains individually claimed more than 39 million lives globally, while millions more people live on with the virus in their bodies, according to the World Health Organization (WHO).

HIV alone only reduces the effectiveness of a victim's immune system, working to turn a body's defenses into factories that actually propagate the illness. Things get really bad when the virus leads to the most advanced stage, Acquired Immunodeficiency Syndrome (AIDS). The WHO reports that it can take two to 15 years for an HIV patient to hit this stage, but once there, the victim can develop certain aggressive cancers, infections, and other severe illnesses with few means to fight back.

And that's the problem with the ongoing HIV problem in Cuba, which is speeding up the advancement to that final stage by threefold, according to initial assessments.

How is this happening? According to a study recently published in the journal EBioMedicine, many Cubans have actually contracted what is called a "circulating recombinant form" of the virus. (Scroll to read on...)

After studying 73 Cuban patients as they progressed through the various stages, an international team of researchers determined that most of the victims boasted a deadly cocktail of three subtypes (A,D, and G) of HIV-1, which have somehow found their way into the region.

The accelerated disease progression, the researchers say, likely has something to do with its use of cellular anchoring points - called a coreceptors - which help the virus gain entry into a cell. You can almost think of these as keys, where coreceptor CXCR4 has long been seen as a 'master key' that quickly leads to AIDS.

In most HIV cases, it takes nearly five years for the virus to find that 'key,' sometimes working towards using a less effective coreceptor known as CCR5 instead.

However, Cuba's deadly recumbent strain, called CRF19, was found to have abnormally high levels of an immune response molecule called RANTES that essentially causes the virus to ignore CCR5 entirely by binding it down. The result is that the HIV works to exclusively make use of CXCR4 - potentially leading to AIDS far earlier than usual.

"We propose," the researchers wrote, "that CRF19 is evolutionary very fit and causing rapid progression to AIDS in many newly infected patients in Cuba."

Thankfully, in understanding this researchers may find ways to help treat or prevent the disease.

A separate team of researchers have even recently determined how to "trap" the virus in a body by essentially hiding the aforementioned keys for good. The result is a strain that slowly dies off on its own without ever gaining access to a body's cells. That could eventually lead to some promising vaccines, but as things stand, there is still much more work to be done.

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