Researchers have discovered a new strain of HIV that progresses to full-blown AIDS within three years. Though a few cases were reported previously in Africa, this is spreading widely in Cuba. If left untreated, can become an epidemic among newly infected patients.

This aggressive strain (named CRF 19) is a combination of HIV subtypes A, D and G.

In Cuba this has been found in people having unprotected sex with multiple partners, according to the study by international medical scientists who published their findings in the Journal of EBioMedicine. This study raises concerns among U.S AIDS researchers.

HIV normally enters human cells by attaching itself to what is called a co-receptor (CCR5) that lies along the CD4 immune cells. Transition to AIDS occurs when the virus switches the CCR5 co-receptor to CXCR4, which often takes several years ( average 5-10 years). The new aggressive strain makes this switching faster, that will open up more cell types to HIV infection, speeding up disease progression towards full-blown AIDS and death. This is so rapid that the patients may not realize they were infected, making early detection and treatment difficult.

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