GWEN IFILL: The spread of HIV -- that scientists hope will save lives, it all comes down to testing.
Of the 1.2 million Americans who carry the virus which causes AIDS, 20 percent don't even know they have it. After diagnosis, the chance that a patient treated with antiretroviral drug will transmit the disease drops by as much as 96 percent.
The Food and Drug Administration has now approved the first at-home test to detect HIV infection.
To explain how it will work, we're joined by Dr. Anthony Fauci, the director of National Institute of Allergy and Infectious Diseases.
Dr. Fauci, I'm struck by that figure that 20 percent of those who are infected don't know that they have the disease. What causes that? Is it stigma? What is it?
DR. ANTHONY FAUCI, Director, National Institute of Allergy and Infectious Diseases: Exactly.
What happens is that there's so many different reasons why people don't come forth to get tested, even though they may realize that they are at some risk. Certainly, stigma is one of them.
The idea of going in and asking for a test would automatically in some circles stigmatize someone. The idea of having a test that a person can get in the privacy of their own home really goes a long way to really breaking down that barrier of getting to the people who are infected and who don't know that they're infected.
GWEN IFILL: Among that 20 percent, who are they? Who are the undiagnosed?
DR. ANTHONY FAUCI: Well, if you look at the relative proportion of people who get newly infected each year, particularly in the United States, they're -- about 50 percent or more of them are African-American, the majority of whom are men who have sex with men, obviously some injection drug users, some heterosexual transmissibility.
But there are a group of people. We have now 50,000 new infections each year in the United States and we haven't gotten below that level for a significant period of time in several, several years. So we really need to do something to get to the people who are infected, to get them into care and on therapy, both for their own good, and the fact that when you put someone on therapy and get the level of their virus low, you dramatically decrease the likelihood that they're going to infect an uninfected sexual partner.
So, there are so many reasons to get them tested.
GWEN IFILL: Let's talk about this test now. How exactly -- it's over the counter. How does it work?
DR. ANTHONY FAUCI: Well, what it is, is that you just take a swab, an inside-the-mouth swab and you put it in a solution and within 20 to 40 minutes, you get the result of whether you're positive or not.
It's very simple. It's very easy to do. And it's going to be available very soon over-the-counter in pharmacies.
GWEN IFILL: Is it something that you would recommend that everyone take, or is it just for people in particularly high-risk groups like you talked about?
DR. ANTHONY FAUCI: Well, obviously, there are people who are in absolutely no risk.
But, for example, the CDC recommends that anyone from a young age up until 60 should be tested for HIV. So, we recommend strongly if there's any doubt whatsoever that you have had any risk -- and risk is easy. Risk is having sex with -- unprotected sex with an individual whose HIV status you don't know.
You may not consider that a risk in your life, but that is a risk. And then there are other risks that are really much more, for example, people who have multiple sexual partners, particularly men who have sex with men. Those are the people who are at the greatest risk in this country. Those are the people you generally like to target, but this is really open for anyone who feels they have any possibility of a risk.
GWEN IFILL: After you have had this, taken this swab, how long does it take before you figure out what the result is? Is it instantly or is it days?
DR. ANTHONY FAUCI: No, it's about 20 to 40 minutes.
But it's important to point out that if you are positive, that you need to get a confirmatory test. And the company that makes this is going to have a 24-hour service, a consumer support service available that you can get information.
For example, if you're positive, you really need to call up and get it confirmed. There's a possibility it might be a false positive. Also, when you are -- if you are indicated as being positive, you want to get yourself into some sort of a health care system to determine if it's appropriate to treat you at this time.
And if it is, you really want to get into treatment. So, it's a matter of literally 20 to 40 minutes, but it doesn't stop there. First of all, if you're negative, you shouldn't assume you're no longer at any risk. You should continue to avoid high-risk behavior. And if you are positive, obviously, you need to get under the care of a health provider.
GWEN IFILL: You mentioned the term false positives. How reliable is this test?
DR. ANTHONY FAUCI: Well, if you are negative, it's 99.9 percent sure that the test would be accurate. In other words, there's a one in 5,000 chance that you're going to have a false positive.
If you are in reality positive, there's a one in 12 chance you may not be picked up as being positive, because there's a window from the time you get infected to the time a test like this turns up positive that's usually measured in a few months, approximately three months.
So there is that sort of blindside window where you don't pick it up. That's the one in 12 that you would miss.
GWEN IFILL: Is there any kind of a tradeoff here? That is to say, you get the privacy. You get to in the privacy of your own home find out whether you are HIV-positive or not.
But then you don't get the follow-up information, the counseling that you might get in a doctor's office.
DR. ANTHONY FAUCI: Well, Gwen, you really do and you can. And that's part of the outreach to people who take these tests, the outreach from the company, the outreach from public health officials.
It doesn't just stop with the test. If indeed you're positive, you have a 24 hour service to get to people who can actually help you, to encourage you and to direct you to getting into a health care system. So although there isn't instantaneous counseling in your home, it's very easy to access that kind of counseling.
So, if you look at the ultimate benefit of something like this, measured against the potential negatives of not having instantaneous counseling, public health officials, people like myself, the FDA, and the CDC overwhelmingly feel that the advantage of this far outweighs the risks.
GWEN IFILL: But, Dr. Fauci, if this is such a valuable and such a wonderful new idea for increasing the number of people who get tested, and we know that this sort of test has been available in medical clinics or in a clinician's environment before, what took so long before this got to be over-the-counter and available for at-home use?
DR. ANTHONY FAUCI: Well, it's been gradual improvement of these.
There has been a test like this that's been available for professional use, namely very rapid and easy to get the answer. You really want to test it thoroughly to make sure you're dealing with a product. We must underscore that the best approach would be would be to go to a physician and get tested as part of general medical care, which is what the CDC recommends.
But there are a group of people who for one reason or other, are very reluctant and reticent to do that. This is directed at those people. This is not directed as a substitute for going to a health care provider and getting tested. These are for the people who for one reason or other find it difficult to do so.
GWEN IFILL: Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, thank you so much for coming on this Fourth of July.
DR. ANTHONY FAUCI: Good to be here.