Scientists have discovered a strain of HIV in West Africa that progresses to AIDS in about five years, the shortest period of any known HIV-1 type, Healio reports. With over 60 different epidemic strains of HIV-1 worldwide—two or three of them are typically predominant in any particular area—it is possible that an individual can become infected with two different strains that eventually combine themselves into what’s known as a recombinant strain as is this new finding.

Publishing their findings in The Journal of Infectious Diseases, researchers from Lund University in Sweden studied 152 people with HIV in Guinea-Bissau in West Africa, determining their HIV subtype or what form of recombinant virus they carried. Then they measured the average duration from the estimated time that the participants acquired the virus until they progressed to AIDS.

The participants carried three major HIV-1 subtypes or circulating recombinant forms (CRFs), as they are known: 53 percent had CRF02_AG, 29 percent had A3, and 13 percent had a recombinant strain of A3 and CRF02_AG called A3/02. Those with this latter, recombinant strain had a 2.6-fold elevated risk of AIDS and a 2.9-fold elevated risk of AIDS-related death when compared with A3.

The researchers found that the estimated time of progression to AIDS or AIDS-related death was a respective 5 and 8 years for A3/02, 6.2 and 9 years for CRF02_AG and 7.2 and 11.3 years for A3.

“HIV is an extremely dynamic and variable virus,” Patrik Medstrand, a professor of clinical virology at Lund University in Sweden and one of the study’s authors, said in a release. “New subtypes and recombinant forms of HIV-1 have been introduced to our part of the world, and it is highly likely that there are a large number of circulating recombinants of which we know little or nothing. We therefore need to be aware of how the HIV-1 epidemic changes over time.”

To read the Healio story, click here.

To read the release on the study, click here.

To read the study abstract, click here.