THE AIDS beds in Irish hospitals have been emptying. People who had given up their jobs because of increasing ill health are now back at work. Parents who were preparing for death can now look forward to more time watching their children grow.
Optimism is a new mood in the area of the HIV virus which has killed more than six million people worldwide and more than 300 in the Republic. For the first time since Acquired Immune Deficiency Syndrome (AIDS) was identified more than 15 years ago there is talk of living with the illness - not dying from it.
The practice of HIV medicine has changed dramatically in Ireland over the past year. The corner has been turned with a new form of treatment which involves giving people who are HIV positive a combination of three different drugs. First discussed publicly at the 11th International Conference on AIDS in Canada in July 1996, this triple or combination therapy, as it is called, has shown dramatic results all over the world.
The names of several new AIDS drugs and some old ones trip off the tongues of doctors and patients including Zerit, 3TC indinavir, ritonavir, saquinavir - the list goes on. Used in powerful triple combination these drugs dramatically reduce the amount of virus in the blood of those that are HIV positive.
Patients undergoing these regimes have had all measurable amounts of HIV eliminated from their blood. There are corresponding improvements in their health. "More miles to the gallon," is how the drugs are being described by those taking them, according to leading Irish AIDS physician Dr Fiona Mulcahy.
Dr Joep Lange, an international AIDS expert, has been one of the principal investigators of more than 10 trials of drugs against HIV which belong to a group known as the retroviruses. With correct use of antiretroviral agents it should be possible to convert HIVinfection into a chronic disease. In an experimental setting attempts at "viral eradication" are even being undertaken, says Dr Lange, director of the recently founded national AIDS therapy evaluation centre, a government sponsored body responsible for undertaking clinical trials in the field of HIV in the Netherlands.
In the US the number of people dying with AIDS has fallen for the first time since the start of the epidemic, according to the latest figures from the Centers for Disease Control and Prevention (CDC). Statistics from the first half of 1996 show that deaths among people with AIDS totalled 22,000, a 13 per cent decline compared with the first half of 1995.
As of June 1996, AIDS prevalence has increased by to per cent since mid 1995, reflecting the decline in AIDS deaths and a stable AIDS incidence, says the report.
"This marks a turning point in the epidemic in the US," says Dr John Ward, CDC chief of HIV/AIDS surveillance in the US. "Treatment advances have led to longer survival for people with AIDS." But this "does bring up the issue of how we track the epidemic in the future". French health officials also report good news - a 25 per cent decline in AIDS deaths in France in 1996.
In Ireland this triple therapy has become the standard of care for people with AIDS and a similar downturn in the number of deaths is expected. The effects have been remarkable, according to the executive director of Dublin AIDS Alliance, Sharyn Oye. "In terms of drug treatment and therapies the change has been enormous. There have been huge strides made in terms of managing people's illness. I know people whose viral loads have gone down to undetectable levels."
The latest figures available for Ireland (end of 1996) show that 1,731 people have tested HIV positive since testing began here. Of these, 577 have developed AIDS and more than half, 304 people, have died of AIDS related illnesses. Intravenous drug users represent 46 per cent of the total number; homosexuals 22 per cent and hetrosexuals 15 per cent. Haemophiliacs, children and others make up the remaining 17 per cent.
The HIV virus works by invading cells of the immune system known as CD4 cells (see graphic). It weaves its genetic material into that of the cell, forcing it to make copies of the virus and eventually killing it.
The new viruses invade other CD4 cells but at the same time the body is producing new CD4 cells. A person with HIV can remain healthy for a long time before the equilibrium tips in favour of the virus and the immune system fails.
Much of the success with triple therapy has been attributable to the use of a new class of antiretroviral drugs called protease inhibitors. These new drugs block an enzyme, protease, crucial to the multiplication of the virus.
These drugs are being used in combination with AZT, a different class of drug widely used as a single treatment in the past, which inhibits a different HIV enzyme, which it uses to copy itself, reverse transcriptase. The idea of combining these drugs is to hit the virus from as many angles as possible.
THE current sense of optimism is tempered, however, by viral resistance which occurs when HIV is able to reproduce and mutate in the presence of antiviral drugs, into a new, drugresistant form. Most experts consider viral resistance to be the greatest obstacle to the successful treatment of AIDS. However new drugs are coming on line all the time. Two more are expected shortly.
Even among patients who initially respond to drug therapy, there are many for whom it fails as the virus becomes resistant to the drugs and multiplies to pretreatment levels despite continued therapy.
The challenge for HIV treatment is to find the best combination of drugs to clear the virus from the blood and improve the CD4 counts over a sustained period of time, allowing the virus no opportunity to build resistance.
There are also difficulties with the regime. Some patients have to take up to 20 tablets a day at various times - some before meals and some after. Side effects include nausea and kidney stones. Even if the virus is eliminated the immune system may be permanently damaged.
Noone knows what will happen if and when patients stop taking the drugs. The treatment appears to keep HIV in check but it remains to be seen if resistant forms of the virus will develop, as happened with earlier HIV drugs.