The Year in HIV/AIDS

TORONTO, Dec. 27 - Researchers and clinicians descended en masse on this city this year for the World AIDS Conference -- the first time in a decade the meeting has been held in North America.

While there was the usual hoopla of demonstrations and political grandstanding, there was also a renewed emphasis on the science of the pandemic, with marathon sessions devoted to new research.

The following summary reviews some of the highlights of the year in HIV/AIDS. For fuller accounts, links to the individual articles published in MedPage Today have been provided.

• IAC: HIV/AIDS Science Regains Center Stage

AIDS World Conference

Among the findings reported at the World AIDS Conference was one that was mildly disappointing in some circles - that adding more drugs to a standard three-drug regimen had no benefit. Adding another drug might have improved efficacy, some researchers had suggested, although the downside might be increased complexity, toxicity, and cost. But a three-year randomized trial scotched that idea.

• IAC: Four HIV Drugs No Better Than Three

On the other hand, the conference was told, once the disease is well in hand, it may be possible to drop two of the three drugs and keep things under control with just one. In patients who had well-controlled HIV and no history of previous virologic failure, the switch was effective, safe, and well tolerated, a Brazilian researcher said.

• IAC: Kaletra Alone Can Keep Suppressed HIV at Bay

The effect of HIV drugs on the heart has long been a concern, especially since many of the medications appear to increase what would normally be thought of as risk factors for cardiovascular disease. A Swedish investigator told the meeting that the cardiovascular effect is real, but small in comparison to the benefit patients get by taking HIV drugs.

• IAC: HIV Therapy's Impact on Heart Disease Small but Bears Watching

Another concern has been the long-term effects of the drugs, especially in children. But based on a cohort study of 133 HIV-positive children long-term treatment of children with protease inhibitor-based therapy appears to be well-tolerated, without apparent developmental abnormalities, a Swiss researcher said.

• IAC: Long-Term Therapy with Antiretrovirals Tolerated by Children

Circumcision

Late in the year, two major U.S.-funded trials in Africa were halted when data monitoring committees agreed the evidence was overwhelming that circumcision cuts the risk of heterosexual transmission of HIV by about 50%. A study of 2,784 HIV-negative men in Kenya found a 53% reduction in HIV acquisition in circumcised men, while a similar trial in 4,996 HIV-negative men in Uganda, showed a 48% reduction. Both trials were prospective and randomized but - for obvious reasons - blinded.

• Circumcision Halves Risk of Heterosexual HIV Transmission

Single Pill

The improvement of highly active anti-retroviral therapy (HAART) may have hit a peak early in 2006, with the approval of Atripla - a single pill, taken once daily, containing 600 mg of Sustiva (efavirenz), 200 mg of Emtriva (emtricitabine), and 300 mg of Viread (tenofovir DF). The three are among the most commonly used anti-HIV medications and are generally regarded as among the most effective as a combination. The co-formulation required three drug companies to work together - one reason the approval was hailed as "an extraordinary achievement."

• FDA Okays Atripla as Once-Daily Therapy for HIV

Mortality

Improvements such as Atripla -- in the number, type, and quality of medications used in HAART have resulted in lower viral loads and higher immune cell counts, according to an international group of researchers. Surprisingly, however, these gains have not translated into a decline in mortality or progression to AIDS. The initial introduction of HAART in the mid-1990s slashed the death rate dramatically, but since then it has remained relatively steady, the researchers said.

• HAART's Improving Control of HIV Has Bottom-Line Limit

Two studies this year showed that the power of HAART is restricted to the blood stream, and has little effect on HIV infection in the gut, the home of a very large proportion of the body's immune cells. The findings suggest that even when HIV is undetectable in the blood, it's percolating away in the gut-associated lymphoid tissue (GALT), which accounts for about 70% of the immune system.

• (HIV Lingers in Gut Despite HAART and
• In HIV Infection, HAART Little Help to Gut Immune Cells)

Drug Holiday

The notion of on-again, off-again drug therapy for HIV was? well ? on and off this year. Two studies suggested that so-called drug holidays were of no benefit and might actually harm patients, while a third study suggested that the idea might still have value and should be revisited.

• HIV Drug Holidays Get New Support, and
• HIV Drug Holidays Not a SMART Idea, and
• CROI: Treatment Interruptions Prove Dismal News for HIV Patients

Testing for All

Despite controversy, the CDC urged this year that HIV tests should be part of routine medical care for all Americans from the ages of 13 to 64, not just those thought to be at high risk for the disease. The goal is to reduce the number of Americans - thought to be about a quarter-million - who are HIV-positive and don't know it. But critics worried that the follow-up - counseling and treatment - would not be in place for another 250,000 patients.

• CDC Urges HIV Tests as Routine in Health Care and
• Proposed HIV Testing Guidelines Draw Fire

Index Chimps

And finally we may know who to blame for HIV. Researchers from Cambridge University said they've traced what appears to be the earliest transmission of simian immunodeficiency virus to humans - by digging into piles of chimpanzee feces in Cameroon, in West Central Africa. The fecal mess yielded viral samples that closely match the HIV-1 taken from the first known victim of AIDS - implying that the blame lies with a troop of chimps living in the region in the late 1950s.