Click on map: New HIV infections in 2007

When AIDS surfaced on the medical radar screens in 1981, the diagnosis was a death sentence.

A researcher holds test tubes with HIV-infected blood that has been separated into red and white blood cells, Feb. 16, 2004, at the laboratory in Hamburg, Germany. (Christof Stache/Associated Press)

But — over the past decade or so — that's begun to change as evidence began to mount that people could live many years with AIDS if they were taking certain drugs.

A November 2006 study in the New England Journal of Medicine provided the strongest evidence yet that life-long antiretroviral therapy had turned HIV/AIDS into a chronic disease rather than a countdown to death.

The study showed that people who take a break from HIV therapy to reduce the side-effects are more than twice as likely to die than those who take a steady course of the drugs.

"Quite unexpectedly, our results show that interrupting therapy increases the risk of serious non-AIDS-related events," Dr. Wafaa El-Sadr, one of the trial's co-chairs, said in a statement. She is a researcher at the Harlem Hospital Center in New York City.

The trial on nearly 5,500 people infected with HIV in 33 countries was stopped early when the advantages of continuing therapy were clear from the preliminary data.

See photographs and read stories from Médecins Sans Frontières patients living with HIV all over the world: In their own words,through their own eyes. (Courtesy MSF)

It's a big leap since 1981, when doctors in New York and Los Angeles noticed that increasing numbers of previously healthy young men were seeking help for symptoms that included severe weight loss, virulent herpes infections, life-threatening lung and brain infections and previously rare cancers. Around the same time, doctors in France, Zaire and Haiti also noticed a similar syndrome in both men and women.

The remarkable thing these patients had in common was that they were dying from infections to which most healthy people were immune. The doctors were puzzled because they could find no obvious cause for this new syndrome. If a line can be drawn in time, then 1981 marks the official beginning of the AIDS epidemic.

Infection rates peaked?

Epidemic update 2008

Essential findings:

• Number of people living with HIV/AIDS in 2007: 33 million worldwide.
• Number of new infections in sub-Saharan Africa: estimated at 1.9 million for 2007 — about 67 per cent of the world total.
• Number of children living with HIV in 2007: two million, 90 per cent of whom live in sub-Saharan Africa.
• Number of new infections in North America: estimated at 54,000 in 2007, while deaths from AIDS in the same region totalled 23,000.
• · The first wave of survivors living 20 years or more is now reaching middle age and they're suffering from rapid onset aging. Years of medication, combined with the effects of the disease itself, means their care needs are again very complex. Heart disease, severe osteoporosis, diabetes, and opportunistic cancers are just some of the ailments they face.

The United Nations said in its report released in July 2008 that the AIDS epidemic had stabilized, although it cautioned governments they would have to continue to direct millions into treatment.

Improvements in treatment have been significant, the report said, with about three million patients taking medication as compared with 300,000 in 2003. The report noted that funding levels will have to be increased notably to achieve a goal of universal access by 2010.

The number of deaths from AIDS in 2007 totalled two million, according to the report – down from 2.2 million 2005.

In June 2008, the UN reported that despite apparent progress in the battle against AIDS, far more people are being infected every year than are getting access to antiretroviral drug treatments. Of the 2.5 million people infected in 2007, only one million began taking antiretroviral drug therapy.

The mystery illness

It was 1981 when doctors in New York and Los Angeles noticed that increasing numbers of previously healthy young men were seeking help for symptoms that included severe weight loss, virulent herpes infections, life-threatening lung and brain infections and previously rare cancers. Around the same time, doctors in France, Zaire and Haiti also noticed a similar syndrome in both men and women.

The remarkable thing these patients had in common was that they were dying from infections to which most healthy people were immune. The doctors were puzzled because they could find no obvious cause for this new syndrome. If a line can be drawn in time, then 1981 marks the official beginning of the AIDS epidemic.

By 1983 French researchers had isolated a virus that would later be called HIV (human immunodeficiency virus). They and others linked this virus to the development of AIDS (acquired immune deficiency syndrome), but a test for exposure to HIV would not become widely available for several more years.

HIV is unusual in that it infects the very cells of the immune system — called T-cells — that protect us from attack by viruses, bacteria and other bugs. Once a person becomes infected, the immune system mounts a counter-attack by producing massive numbers of T-cells. For a time, the virus appears to be contained. Indeed, on the outside, the average HIV-positive person appears no different from an average healthy person.

Yet inside the body of someone with HIV infection rages a vast war, as billions of viruses and T-cells are created and destroyed in a single day. The body cannot sustain the expenditure forever, and the virus slowly gains the upper hand. After 10 years or more of battle the immune system begins to collapse. At this point, infections that are, at worst, annoying for the average person, turn lethal as AIDS develops. Overwhelmed by wave after wave of infection, the body eventually gives in.

Initially considered a mysterious gay plague, researchers now know that HIV is transmitted through unprotected sex, by sharing needles used for injecting drugs, from transfusions of contaminated blood and from breast feeding by infected mothers. HIV has now spread to the point where one per cent of sexually active adults around the globe have the virus.

The situation in Canada

AIDS in Canada

• An estimated 58,000 people had HIV/AIDS in 2006.
• Every two hours, someone in the country becomes infected with HIV.
• Over 27 per cent of infected people don't know they have HIV.
• Women now account for one-fifth of people with HIV/AIDS, up from one-tenth in 1995.

Canada recorded its first case of AIDS in 1982. The Public Health Agency of Canada estimates that by the end of 2005, there were about 58,000 people living with HIV-AIDS. Of those, the agency estimates that 15,000 — or just over 25 per cent — don't know it.

The agency says Canada's infection rates have remained relatively stable at approximately 2,500 new cases a year. However, death rates have fallen as medical advances increase the life expectancy of infected people.

The greatest proportion of new infections continues to be among men having sex with men, at 45 per cent. Women accounted for 27 per cent of new infections and now make up more than 20 per cent of the population of people living with HIV-AIDS. But the rate of infection among aboriginals is growing faster than any other group. They accounted for nine per cent of new infections in 2005, an overall infection rate that is nearly three times higher than among non-aboriginals.

Although the number of deaths caused by AIDS has fallen since 1996, Health Canada calls the epidemic "severe and deeply troublesome," and says Canadians should not be complacent.