In the wake of Charlie Sheen's announcement on Tuesday's the Today show, in which the 50-year-old actor confirmed he is HIV positive, ET spoke to an expert medical researcher about some commonly asked questions regarding HIV and AIDS.
Dr. Gary Cohan, an Internal Medicine-specializing physician and medical researcher who has worked in the field of HIV/AIDS for more than 25 years, is well-versed on Sheen's HIV status, because he has consulted with Sheen's primary doctor, Dr. Robert Huizenga, for four years.
WATCH: Charlie Sheen Reveals He's HIV Positive
On the Today show, Sheen was optimistic and explained that he owes his health to a cocktail of HIV medications that can keep the virus at an "undetectable" level. Dr. Cohan further clarified exactly what this means.
1. What does the term "undetectable" mean?
Dr. Gary Cohan: The word "undetectable" doesn't mean that the HIV isn't in Charlie's system. It just means that we've suppressed it with medication to such low levels that our current laboratory test can't detect it, but if Charlie stopped his medicines, the HIV would come roaring back.
2. Can someone with undetectable HIV transmit the virus to a sexual partner?
Cohan: When somebody's viral load is undetectable, it is nearly mathematically impossible to transmit it to a sexual partner. It's not completely impossible, but they've done a few studies. One is called the Partner Study, showing that nobody in an HIV-positive/negative relationship transmitted their HIV to their HIV-negative partner if they were undetectable on their viral load.
3. How is HIV treated?
Cohan: What Dr. Huizenga does with Charlie, as his primary doctor managing his HIV, is make sure Charlie's taking his medicines, monitor his T-cells, which are his immune cells, and his viral load, meaning how much virus is in his body. We do that about every three to six months these days. We've kind of calmed down about how often we do it, because the medicines are working extremely well. As far as going forward with Charlie, [we'd like to evolve] his regimen to newer, cleaner and easier medications.
4. What is the HIV cocktail?
Cohan: The HIV cocktail is interesting, because all that means is that we're using at least three drugs to treat the HIV virus. What's so cool in the last several years is that we've boiled all those three drugs down to one pill, once a day. We have four different HIV medicines that are a whole cocktail in a single pill, once a day, so it's become very easy and the medications are extremely non-toxic, and people are doing amazingly well. It's totally different than what it was 20 years ago.
5. How could past drug use affect treatment?
Cohan: Charlie has had a history of drug and alcohol use, and Charlie's doctor said something on the Today show that I think is very important. He used the word "petrified" about Charlie. I don't know that I'd use the word petrified, but if somebody is using drugs and alcohol, maybe they won't take their medicines every day like they need to and maybe their viral load will become out of control. Then we have a bit of a problem, because that's when the virus can mutate or can be transmitted to another person.
6. What is the prognosis for people diagnosed with HIV in 2015?
Cohan: If you have access to medications there is no way HIV is going to be a death sentence. Unfortunately though -- this is a scary statistic -- 60 percent of people in the United States with HIV are not taking any medications. Only 40 percent of people with HIV are in treatment. That means that HIV for those people who are not taking medicine because of the stigma, or they can't afford it, or they don't have insurance, whatever reason -- it could be a death sentence for them. What we need to do is increase awareness, which is the beauty of what Charlie did today.
7. What is the prognosis for someone like Charlie Sheen who has access to medications?
Cohan: Here's the good news. Charlie's long-term prognosis with HIV is the same as a person without HIV. I know that's kind of hard to believe, but with the current therapies, HIV should not affect Charlie's lifespan.
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8. What is the difference between AIDS and HIV?
Cohan: HIV is just an infection with a virus. AIDS is when your immune system has been destroyed by the HIV virus, and then you're prone to what are called opportunistic infections, and you could possibly die. Charlie does not have AIDS. Charlie just has a symptomatic HIV that's very well controlled.
9. What is the risk of missing a dose of the medication?
Cohan: Different medicines have different amounts of what we call forgiveness. If you start to miss doses, that's when you begin to be at risk for resistance. Since there's over 30 different HIV medicines, some last very long in the body, and with those, if you miss a dose, you might be OK. Some have a very short period of action in the body, so if you miss those, you might get in trouble and become resistant. Just because you're resistant doesn't mean we have no options for you. We just possibly have to go to different or more complex regimens, but you really need to be what we call compliant and take your medicines every day. There's a very new development that just happened. We're coming out, hopefully before 2020, with a shot that you can take once every month or every two months without pills that will do the same that daily medications will do and suppress HIV fully.
10. How does drinking and smoking affect the treatment?
Cohan: Unfortunately, we are finding a much higher risk of heart disease and lung cancer in HIV-positive patients who smoke versus HIV-negative patients, so it would be a really good thing if Charlie could quit the nicotine habit. In terms of alcohol and other things, it's not good for the immune system, but the best thing Charlie could do right this second is quit smoking.
11. How has HIV treatment changed over the years?
Cohan: In the 20 years since Greg Louganis announced that he was HIV positive to Oprah, we've done a complete 180 on the HIV epidemic. It is no longer a uniformly fatal disease, and we have easy, once-a-day treatments, so the 60 percent of [HIV-positive] Americans who are out there that are not in treatment need to understand that. They need to realize it's safe, it's easy and to take advantage of that.