VOA标准英语2013--Antiretrovirals Allow Near Normal Life Spans（在线收听）

Antiretrovirals Allow Near Normal Life Spans

Antiretroviral drugs have saved the lives of millions of people infected with the HIV, the AIDS virus. Now, new research shows HIV-infected people, who start treatment, can expect near normal life spans. The study was conducted in South Africa.

In 2011, South Africa had about 5.6 million people infected with HIV - more than any other country. That same year, over 270,000 people in South Africa died from AIDS-related illnesses and complications. So the more information health officials can gather about the disease, the better they can project treatment plans and costs.

University of Cape Town’s Dr. Leigh Johnson collected data on treatment programs between 2001 and 2010. The study did not start out to specifically look at longevity.

“I think partly it was concern about the life insurance policies that were being provided to people with HIV. And in many cases people with HIV were being charged very high premiums. And we were worried about whether or not these very high premiums were really justified by the mortality risk in patients once they were on treatment,” he said.

There was a second aspect to the study.

“It was also partly motivated by an attempt to understand the extent to which antiretroviral treatment is reducing overall levels of mortality in South Africa. So we are involved in producing demographic forecasts for South Africa; and in order to produce these democratic forecasts we need estimates of how long people are surviving on antiretroviral treatment,” said Johnson.

The overall findings show treatment can enable people to live a near normal life span. However, Johnson said that patients must meet a few conditions for that to happen. The first is the stage of disease at the time treatment begins. That’s measured by the number of CD4 immune cells that have survived the onslaught of HIV.

“Previously, the treatment guidelines in South Africa recommended that patients defer their initiation of therapy until their CD4 count had dropped below 200 cells per microliter. That’s quite an advanced stage of disease to be starting treatment. And what we showed was that patients who started treatment before reaching that threshold of 200 cells per microliter had much high life expectancies than those patients who only waited until their CD4 count was below the 200 threshold,” he said.

Basically, at the 200 level the immune system has collapsed and the patient is an easy target for opportunistic infections.

There are newer World Health Organization guidelines that South Africa currently follows. It now tries to begin treatment when the CD4 count is at 350, a marked difference in the health of the immune system. However, despite that, Johnson said many people are still waiting until advanced stages of disease before seeking treatment. It’s a problem many countries now face.

Another factor was age. A 20 year old patient would naturally have a longer life expectancy than a 60 year old. The findings showed the 20 year old would get an additional 27 years of life and the 60 year old an extra 10.

So, what does it all mean?

“From a demographic point of view it means that our projections of mortality are going to be much lower than what we were expecting previously. But it does also mean that we are expecting many more long term survivors on antiretroviral treatment in [the] future. So we’re going to have a much greater older age population than was previously anticipated. And I think it’s important from a kind of a fiscal point of view because we obviously need to budget for the long term provision of treatment for these patients,” he said.

South Africa funds about 80 percent of its national treatment program through its own resources. Johnson said that it’s difficult to determine whether it will be able to sustain that as the number of people on treatment grows. Another factor will be the cost of new generations of antiretroviral drugs that will be needed as HIV builds resistance to current drugs.