HIV is something no person really chooses to live with and in Cuba a new and even more aggressive form was identified recently. This virus is the result of having unprotected sex with multiple partners who have HIV, so that the HIV strains combine into a new HIV variant. Patients sometimes didn't even know they were infected and AIDS occurs within 3 years of their first HIV infection.
HIV normally anchors to co-receptors - proteins on the membranes of cells. First it anchors to CCR5 and after a few more or less healthy years, to CXCR4. When this happens, a faster progression to AIDS occurs. The Cuban virus quickens the transition to CXCR4 after infection and reduces the healthy phase, which means the progression to AIDS happens a lot faster.
Researchers compared the blood of people with this ‘new' virus with blood of people with the known HIV virus. The patients with the new HIV variant had high doses of the virus and RANTES, which are defensive molecules. RANTES is part of the immune response and it binds to CCR5. Because there is such a high dose of it, it suggests that CCR5 proteins weren't good anchor points for this variant of HIV and the virus went straight to the CXCR4. Normally the transition from CCR5 to CXCR4 is difficult, but a protease was found in the new and aggressive HIV, which is an enzyme that enables viruses to replicate in great numbers.
This virus is said to be the most aggressive virus ever studied in humans. Reason enough to protect yourself, right?