By Bob Huff
Online webcasts make CROI (the Conference on Retroviruses and Opportunistic Infections) the most accessible major scientific meeting on AIDS. Webcasts are accessed through the main website at www.retroconference.org/2008. Click on View the Webcasts and Podcasts. The webcast sessions are accessed by clicking tabs corresponding to the Conference Day, Sunday through Wednesday. Click on the Speaker Name tab at the top of the page and you will see an alphabetical list of speakers for each of the conference days. Select one of the viewing options on the buttons to the right and wait for the slides to download onto your computer. The program will automatically begin to play the program you have selected. The viewing console allows you to enlarge the slide display or to skip back or forward through the presentation. If you click Index you will be able to view other presentations by speakers who participated in that session.
The annual Conference on Retroviruses and Opportunistic Infections—known as CROI—is the most important AIDS research meeting of the year. Thousands of the best scientists and doctors from around the world—and the world recognized by CROI increasingly includes Africa and Asia—meet for three days to look at the latest data and discoveries about HIV and the diseases that accompany it.
CROI is dominated by technical topics. Unlike the biannual International AIDS Conference there is little discussion of the economic, social, and psychological reasons why this virus is so pervasive and so destructive. For a nonscientist, much of this conference is incomprehensible. But with a little orientation, insights into the newest and most exciting ideas about understanding and defeating HIV can be grasped. At CROI one can get a glimpse of how HIV infection might one day be prevented, disabled, and even cured.
CROI is a uniquely accessible conference because all of the main science sessions are made available on the Web for free viewing as soon as the meeting is over. Webcasts offer video and audio of the presenter, while his or her slide presentation displays in a separate window. Those with slower Internet connections can skip the video and simply listen to the presenter, along with a slide presentation.
Here are a few highlights from this year’s CROI webcasts.
SUNDAY, FEBRUARY 3, 2008
A special orientation program for young investigators was presented on Sunday before the conference officially began. This session offers a preview of important news emerging at the conference, accompanied by basic background lectures intended to introduce newcomers to the field. This is an excellent place to plunge into learning about what’s new in AIDS research.
The Early AIDS Epidemic in the US: Views from Atlanta and Hollywood
Do you know the story of how AIDS appeared 27 years ago? In this moving presentation, illustrated by clips from the Hollywood film And the Band Played On (based on Randy Shilts’s book of real-life reportage), Harold Jaffe recalls how the horrifying disease was first recognized and how he and his medical-detective colleagues slowly came to understand that a sexually transmitted, deadly new virus was spreading throughout the country. This presentation is aimed at young doctors, some of whom had not yet been born in 1981. For those who were young in those days, it’s difficult to recall a time before AIDS. It’s also painful to remember that nearly 15 torturous years ticked by until effective treatments finally stemmed the tide of death in 1995. Jaffe’s presentation is easily one of the most engaging and educational of the CROI webcasts. Must viewing.
HIV/AIDS: Where Is It Going and What Does It Mean?
Kevin De Cock
Do you know that 40,000 to 60,000 people in the United States become infected with HIV every year? Did you know that over one million people in the United States have been infected with HIV since the epidemic began—and that half of them have died? Kevin DeCock provides a simple and clear orientation to the epidemiology of HIV in this country and around the world. Because many years can pass following HIV infection before serious disease appears, the virus can spread widely in a population before it is recognized. In most places in the world the peak rate of new infections has now passed. But this early peak is accompanied by a rising number of deaths that may follow many years later. This second deadly peak still lies in the future for many countries. However, as an increasing number of people around the globe gain access to HIV treatment, the peak in deaths may be blunted, as fewer will die of AIDS and the total number of people living with HIV grows.
Cellular and Viral Factors in HIV-Host Cell Interplay
The science is tough going, but Stevenson looks at some of the hottest topics in HIV research and gives us a glimpse of possible future treatments.
Because HIV has a very limited set of its own genes with which to work, it depends heavily on resources found in its host’s cellular environment (and several hundred new host proteins that enable HIV have recently been uncovered). Some host proteins act as anti-HIV factors, however, and HIV carries three small “accessory” genes that can defeat these natural defenses. When these viral proteins are switched off, HIV is unable to replicate, which makes the accessory proteins potentially exciting targets for a new type of drug therapy that would unleash the body’s natural HIV blockers.
It is commonly imagined that infected cells shed virus particles into the bloodstream, where they travel until they meet and infect new target cells. Stevenson now thinks it “highly unlikely” that this is the main way infection spreads. New evidence (and there are amazing pictures that show this in action) finds that infected cells actually send out long, skinny tendrils that contact fresh cells directly and pass viruses—including HIV—like beads along a string. Video footage of how this happens can be found in Walter Mothes’s symposium on Monday, February 4 (see box).
TUESDAY, FEBRUARY 5, 2008
Symposium: Aging and AIDS
Justice relates that it is not only HIV and the drugs used to suppress the virus that determine the health outcome of an infected individual, but also drug side effects and interactions between drugs; the non-AIDS-related effects of HIV; other infections, illnesses, and addictions; and, increasingly, the effects of aging. For example, lifestyle issues such as obesity and inactivity are now playing a greater role in the health status of people with HIV.
Justice outlines challenges that face researchers concerned with studying an aging HIV population: How does one select comparison groups when looking at cardiovascular event rates in people with HIV to see if there is an increased risk? As she points out, comparisons with wellestablished cohorts of mostly white men are unlikely to be of much value.
Bruno Ledergerber describes the epidemiology of aging in the Swiss HIV population. The proportion of persons over the age of 40 has been growing steadily, with longer life due to treatment being a primary factor. Trends in new infections show an increasing proportion of injection drug users (IDUs) and, looking ahead, Ledergerber predicts a significant number of former or current IDUs over the age of 40 burdened with other risk factors, including drug and alcohol dependencies, tobacco use, and hepatitis C.
In the United States, the proportion of women with HIV over the age of 50 is increasing faster than that of their male counterparts. But this may not only be a story about people living longer with HIV; one study has shown that the median age at the time of seroconversion has been increasing. And an increasing number of older people are being diagnosed with HIV, often with more advanced disease symptoms and lower CD4 counts when they first come into care.
Older people may be overlooked by medical providers who don’t perceive them as being at risk, while at the same time certain HIV symptoms may be attributed to aging. Yet older people may be at a higher risk for HIV than they think. This population is rarely targeted for safer-sex messages and HIV education, and since such messages are targeted at youth, older people may not believe HIV is something that can affect them. Condom use may not be thought necessary by postmenopausal women, and men with erectile dysfunction may not like condoms. But older people may have active sex lives. Enabled by Viagra, and with free time after retirement or divorce, an increasing number of older people are exploring their sexuality.
Some studies have shown that when older people are infected with HIV they may progress faster to disease. Also, liver and kidney illnesses, which naturally increase with age, do so faster in people with HIV. Furthermore, rates of non-AIDS types of cancer increase rapidly in people with HIV over the age of 50 compared to their non-AIDS counterparts.
In a bit of good news, when older people go on antiretroviral therapy, HIV tends to become suppressed faster than in younger people, though Ledergerber thinks this may be due to poor medication adherence among younger people rather than to a biological factor. Better virologic control results in improved CD4 response, but these gains are partially outweighed by the greater burden of other disease factors that affect older people with HIV.
And there is much more…
These are just a few of the more accessible presentations available at www.retroconference.org/2008. Other sessions on mother-to-child HIV transmission, breast feeding, and the threat of drug-resistant tuberculosis are equally interesting and important topics to explore. CROI’s free webcasts are invaluable for delivering this wide range of lectures by the world’s top experts to all who want to understand the state of AIDS in 2008.
MONDAY, FEBRUARY 4, 2008
Symposium: Voyages through the Cell: Imaging Viral Traffic; Live Imaging of Cell-to-Cell Transmission of Retroviruses
Microwave some popcorn and watch these cool, time-lapse videos of immune cells communicating with each other and of viruses surfing along strands of filopedia to infect fresh cells. Advances in imaging are shaking up some old ideas about how the virus replicates. Simply amazing.