“Determining the HIV-1 subtype of infected individuals could be important in the management of HIV-1 infections,” say A3/O2 study authors. (Photo: GIZMODO)
Guinea-Bissau, West Africa, appears to have generated the newest strain of the HIV/AIDS virus.
In recent years, health experts have begun to think of HIV/AIDS as a treatable, nonlethal disease. Seventeen people treated with cell transplants or early antiretroviral drugs have had documented cures, and dozens of different antiviral treatments have been developed. Just 10 days ago, the European Medicine Agency recommended approval of Tivicay (dolutegravir), a new drug from GlaxoSmithKline that is expected to draw major sales.
The immunity-draining virus currently affects about 35 million people worldwide. Full-blown AIDS kills over 1.7 million people per year. Since its discovery in the last quarter-century of the 1900s, HIV/AIDS has killed 35 million. With the apparent success of early treatment, in June the World Health Organization proposed raising the standard for treatment from a blood count of 350 CD4 cells to 500 per milliliter.
However, Mother Nature appears to be upping the stakes. A team of researchers from the Department of Experimental Medical Science of Sweden’s Lund University has recently studied a new recombinant form of the virus that progresses significantly faster and with more killing power than those identified previously.
The recombinant, a cross between Guinea-Bissau’s two most common strains (02AG and A3), is called A3/02. Joakim Esbjörnsson of Oxford, a coauthor on the 2013 paper, first described A3/02 in 2011. Angelica A. Palm et al. summarize the hands-on findings about the virus in the Journal of Infectious Diseases: “Faster progression to AIDS and AIDS-related death among seroincident individuals infected with recombinant HIV-1 A3/CRF02_AG compared with sub-subtype A3.”
People with this strain are three times more likely to develop AIDS and suffer an AIDS-related death than others with the predecessor strain. The new subtype develops AIDS from HIV in about five years, about two to two-and-a-half years faster than one of the parent strains alone.
The researchers studied long-term health in 152 people with HIV in Guinea-Bissau. The most common locus for AIDS, sub-Saharan Africa has HIV in nearly one of every 20 adults (4.9%). These individuals account for almost 70% of the worldwide HIV population.
From the abstract of the Lund study:
Human immunodeficiency virus type 1 (HIV-1) is divided into subtypes and circulating recombinant forms (CRFs) but the impact of subtype/CRF on disease progression is not fully understood…. Hazard ratios (HRs) were calculated using a Cox proportional hazard model, adjusting for gender and age at seroconversion…. The major subtypes/CRFs identified were CRF02_AG (53%), A3 (29%), and A3/02 (a recombinant of A3 and CRF02_AG) (13%). Infection with A3/02 was associated with a close to 3-fold increased risk of AIDS and AIDS-related death compared to A3 (HR = 2.6 [P = 0.011] and 2.9 [P = 0.032], respectively). The estimated time from seroconversion to AIDS and AIDS-related death was 5.0 and 8.0 years for A3/02, 6.2 and 9.0 years for CRF02_AG, and 7.2 and 11.3 years for A3…. Our results show that there are differences in disease progression between HIV-1 A-like subtypes/CRFs.
Patrik Medstrand, Professor of Clinical Virology at Lund and the study’s senior author, provides these insights: “HIV is an extremely dynamic and variable virus. 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.”
“The good news is that as far as we know the medicines that are available today are equally functional on all different subtypes of variants,” says first author Angelica Palm.
The authors at Lund reportedly plan further studies of combined HIV viruses in Europe.