What Is HIV?
To understand what HIV is, let’s break it down:
H – Human – This particular virus can only infect human beings.
I – Immunodeficiency – HIV weakens your immune system by destroying important cells that fight disease and infection. A "deficient" immune system can't protect you.
V – Virus – A virus can only reproduce itself by taking over a cell in the body of its host.
Human Immunodeficiency Virus is a lot like other viruses, including those that cause the "flu" or the common cold. But there is an important difference – over time, your immune system can clear most viruses out of your body. That isn't the case with HIV – the human immune system can't seem to get rid of it. Scientists are still trying to figure out why.
We know that HIV can hide for long periods of time in the cells of your body and that it attacks a key part of your immune system – your T-cells or CD4 cells. Your body has to have these cells to fight infections and disease, but HIV invades them, uses them to make more copies of itself, and then destroys them.
Over time, HIV can destroy so many of your CD4 cells that your body can't fight infections and diseases anymore. When that happens, HIV infection can lead to AIDS.
What Is AIDS?
To understand what AIDS is, let’s break it down:
A – Acquired – AIDS is not something you inherit from your parents. You acquire AIDS after birth.
I – Immuno – Your body's immune system includes all the organs and cells that work to fight off infection or disease.
D – Deficiency – You get AIDS when your immune system is "deficient," or isn't working the way it should.
S – Syndrome – A syndrome is a collection of symptoms and signs of disease. AIDS is a syndrome, rather than a single disease, because it is a complex illness with a wide range of complications and symptoms.
Acquired Immunodeficiency Syndrome is the final stage of HIV infection. People at this stage of HIV disease have badly damaged immune systems, which put them at risk for opportunistic infections (OIs).
You will be diagnosed with AIDS if you have one or more specific OIs, certain cancers, or a very low number of CD4 cells. If you have AIDS, you will need medical intervention and treatment to prevent death.
Where did HIV come from?
Scientists believe HIV came from a particular kind of chimpanzee in Western Africa. Humans probably came in contact with HIV when they hunted and ate infected animals. Recent studies indicate that HIV may have jumped from monkeys to humans as far back as the late 1800s.
How do you get HIV?
HIV is found in specific human body fluids. If any of those fluids enter your body, you can become infected with HIV.
Which body fluids contain HIV?
HIV lives and reproduces in blood and other body fluids. We know that the following fluids can contain high levels of HIV:
- BloodSemen (cum)
- Pre-seminal fluid (pre-cum)
- Breast milk
- Vaginal fluids
- Rectal (anal) mucous
Other body fluids and waste products—like feces, nasal fluid, saliva, sweat, tears, urine, or vomit—don’t contain enough HIV to infect you, unless they have blood mixed in them and you have significant and direct contact with them.
Healthcare workers may be exposed to some other body fluids with high concentrations of HIV, including:
- Amniotic fluid
- Cerebrospinal fluid
- Synovial fluid
How Is HIV transmitted through body fluids?
HIV is transmitted through body fluids in very specific ways:
- During sexual contact: When you have anal, oral, or vaginal sex with a partner, you will usually have contact with your partner’s body fluids. If your partner has HIV, those body fluids can deliver the virus into your bloodstream through microscopic breaks or rips in the delicate linings of your vagina, vulva, penis, rectum, or mouth. Rips in these areas are very common and mostly unnoticeable. HIV can also enter through open sores, like those caused by herpes or syphilis, if infected body fluids get in them.
You need to know that it’s much easier to get HIV (or to give it to someone else), if you have a sexually transmitted disease (STD). For more information, see CDC's The Role Of STD Detection And Treatment In HIV Prevention.
- During pregnancy, childbirth, or breastfeeding: Babies have constant contact with their mother’s body fluids-including amniotic fluid and blood-throughout pregnancy and childbirth. After birth, infants can get HIV from drinking infected breast milk.
- As a result of injection drug use: Injecting drugs puts you in contact with blood-your own and others, if you share needles and “works”. Needles or drugs that are contaminated with HIV-infected blood can deliver the virus directly into your body.
- As a result of occupational exposure: Healthcare workers have the greatest risk for this type of HIV transmission. If you work in a healthcare setting, you can come into contact with infected blood or other fluids through needle sticks or cuts. A few healthcare workers have been infected when body fluids splashed into their eyes, mouth, or into an open sore or cut.
- As a result of a blood transfusion with infected blood or an organ transplant from an infected donor: Screening requirements make both of these forms of HIV transmission very rare in the United States.
How do you get AIDS?
AIDS is the late stage of HIV infection, when a person’s immune system is severely damaged and has difficulty fighting diseases and certain cancers. Before the development of certain medications, people with HIV could progress to AIDS in just a few years. Currently, people can live much longer - even decades - with HIV before they develop AIDS. This is because of “highly active” combinations of medications that were introduced in the mid 1990s. Read more about how HIV causes AIDS.
Early Stage of HIV: Symptoms
The symptoms of HIV vary, depending on the individual and what stage of the disease you are in.
Within 2-4 weeks after HIV infection, many, but not all, people experience flu-like symptoms, often described as the “worst flu ever.” This is called “acute retroviral syndrome” (ARS) or “primary HIV infection,” and it’s the body’s natural response to the HIV infection.
Symptoms can include:
- Fever (this is the most common symptom)
- Swollen glands
- Sore throat
- Muscle and joint aches and pains
These symptoms can last anywhere from a few days to several weeks. However, you should not assume you have HIV if you have any of these symptoms. Each of these symptoms can be caused by other illnesses. Conversely, not everyone who is infected with HIV develops ARS. Many people who are infected with HIV do not have any symptoms at all for 10 years or more.
You cannot rely on symptoms to know whether you have HIV. The only way to know for sure if you are infected with HIV is to get tested. If you think you have recently been exposed to HIV—if you have had oral, vaginal or anal sex without a condom with a known HIV positive person or a partner whose HIV status you do not know or shared needles to inject drugs—get an HIV test. Traditional HIV tests detect HIV antibodies. But during this early stage your body is not yet producing these antibodies. A new HIV test was approved in 2013 that can detect the presence of HIV in your body during this early stage of infection. So no matter where you get tested, it is very important to let your provider know that you may have been recently infected with HIV and you would like to be tested for acute HIV. Use theHIV/AIDS Testing and Services Locator to find a HIV testing site near you.
It is important to remember that with or without symptoms, you are at particularly high risk of transmitting HIV to your sexual or drug using partners during this time because the levels of HIV in your blood stream are very high. For this reason, it is very important to take steps to reduce your risk of transmission.
The clinical latency stage
After the early stage of HIV infection, the disease moves into a stage called the “clinical latency” stage. “Latency” means a period where a virus is living or developing in a person without producing symptoms. During the clinical latency stage, people who are infected with HIV experience no HIV-related symptoms, or only mild ones. (This stage is sometimes called “asymptomatic HIV infection” or “chronic HIV infection.”)
During the clinical latency stage, the HIV virus reproduces at very low levels, although it is still active. If you take antiretroviral therapy (ART), you may live with clinical latency for several decades because treatment helps keep the virus in check. (Read more about HIV treatment.) For people who are not on ART, this clinical latency stage lasts an average of 10 years, but some people may progress through this phase faster.
It is important to remember that people in this symptom-free period are still able to transmit HIV to others even if they are on ART, although ART greatly reduces the risk of transmission.
Again, the only way to know for sure if you are infected with HIV is to get tested. Tests are available that can detect the virus at this stage. Use the HIV/AIDS Testing and Services Locator to find a HIV testing site near you.
Progression to AIDS: symptoms
If you have HIV and you are not taking HIV medication (antiretroviral therapy), eventually the HIV virus will weaken your body’s immune system. The onset of symptoms signals the transition from the clinical latency stage to AIDS (Acquired Immunodeficiency Syndrome).
During this late stage of HIV infection, people infected with HIV may have the following symptoms:
- Rapid weight loss
- Recurring fever or profuse night sweats
- Extreme and unexplained tiredness
- Prolonged swelling of the lymph glands in the armpits, groin, or neck
- Diarrhea that lasts for more than a week
- Sores of the mouth, anus, or genitals
- Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids
- Memory loss, depression, and other neurologic disorders.
Each of these symptoms can be related to other illnesses. So, as noted above, the only way to know for sure if you are infected with HIV is to get tested.
Many of the severe symptoms and illnesses of HIV disease come from the opportunistic infections that occur because your body’s immune system has been damaged.
Treatment for HIV
In 1987, a drug called AZT became the first approved treatment for HIV disease. Since then, approximately 30 drugs have been approved to treat people living with HIV/AIDS, and more are under development.
You may have heard these drugs called many different names, including:
- "The Cocktail"
- Antiretrovirals (ARVs)
- Highly Active Antiretroviral Therapy (HAART or ART)
There are currently five different "classes" of HIV drugs. Each class of drug attacks the virus at different points in its life cycle—so if you are taking HIV meds, you will generally take 3 different antiretroviral drugs from 2 different classes.
This regimen is standard for HIV care—and it’s important. That’s because no drug can cure HIV, and taking a single drug, by itself, won’t stop HIV from harming you. Taking 3 different HIV meds does the best job of controlling the amount of virus in your body and protecting your immune system.
Taking more than one drug also protects you against HIV drug resistance. When HIV reproduces, it can make copies of itself that are imperfect—and these mutations may not respond to the drugs you take to control your HIV. If you follow the 3-drug regimen, the HIV in your body will be less likely to make new copies that don’t respond to your HIV meds.
Each HIV medication is pretty powerful by itself—and the key to treating your HIV disease successfully is to pick the right combination of drugs from the different classes of HIV meds.
Antiretrovirals are separated into different classes by the way an individual drug stops HIV from replicating in your body. The classes include:
Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs): Sometimes called "nukes." These drugs work to block a very important step in HIV’s reproduction process. Nukes act as faulty building blocks in production of viral DNA production. This blocks HIV’s ability to use a special type of enzyme (reverse transcriptase) to correctly build new genetic material (DNA) that the virus needs to make copies of itself.
Non-nucleoside reverse transcriptase inhibitors (NNRTIs): These are called "non-nukes." They work in a very similar way to "nukes." Non-nukes also block the enzyme, reverse transcriptase, and prevent HIV from making copies of its own DNA. But unlike the nukes (which work on the genetic material ), non-nukes act directly on the enzyme itself to prevent it from functioning correctly.
Protease inhibitors (PIs): When HIV replicates inside your cells, it creates long strands of its own genetic material. These long strands have to be cut into shorter strands in order for HIV to create more copies of itself. The enzyme that acts to cut up these long strands is called protease. Protease inhibitors (stoppers) block this enzyme and prevent those long strands of genetic material from being cut up into functional pieces.
Entry/fusion inhibitors: These medications work to block the virus from ever entering your cells in the first place. HIV needs a way to attach and bond to your CD4 cells, and it does that through special structures on cells called receptor sites. Receptor sites are found on both HIV and CD4 cells (they are found on other types of cells too). Fusion inhibitors can target those sites on either HIV or CD4 cells and prevent HIV from "docking" into your healthy cells.
Integrase inhibitors: HIV uses your cells’ genetic material to make its own DNA (a process called reverse transcription). Once that happens, the virus has to integrate its genetic material into the genetic material of your cells. This is accomplished by an enzyme called integrase. Integrase inhibitors block this enzyme and prevent the virus from adding its DNA into the DNA in your CD4 cells. Preventing this process prevents the virus from replicating and making new viruses.
Fixed-dose combinations: These are not a separate class of HIV medications but combinations of the above classes and a great advancement in HIV medicine. They include antiretrovirals which are combinations of 2 or more medications from one or more different classes. These antiretrovirals are combined into one single pill with specific fixed doses of these medicines.
Which medications are right for you?
Your provider will take many things into account when considering which HIV medications to prescribe for you. These will include your preferences (number of pills, once a day versus twice, etc.), the general state of your health (including your CD4 count) possible side effects, your medical and psychiatric history, etc. You should talk with your provider about the choice of medications, including possible side effects and how you should take them.
Sometimes your HIV medications may be only a part of the whole package of meds you may take. If you are at risk for opportunistic infections, your healthcare provider may also put you on daily or weekly medications to prevent your getting sick with a specific kind of infection. This type of treatment is known as prophylaxis.
In addition, you may take other medications to prevent side-effects. These can include meds to prevent diarrhea, nausea, or pain. If you have other health problems (like high blood pressure or diabetes), you may also need to take medications to treat those conditions. All of these medications work together to keep you as healthy as possible while complementing your treatment for HIV.
It is important to discuss ALL of your medications when you see your provider, because each one is important to the success of your whole treatment plan.
This information was developed by Aids.gov.
AIDS.gov. What is HIV/AIDS? Available at: https://aids.gov/hiv-aids-basics/hiv-aids-101/what-is-hiv-aids/. Accessed February 10. 2014.
AIDS.gov. Overview of HIV Treatments. Available at: https://aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/treatment-options/overview-of-hiv-treatments/. Accessed February 10, 2014.
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