What is HIV?
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Human immunodeficiency viruses.
The human immunodeficiency viruses (HIV) are two species of Lentivirus (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.
Without treatment, the average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype. In most cases, HIV is a sexually transmitted infection and occurs by contact with or transfer of blood, pre-ejaculate, semen, and vaginal fluids. Research has shown (for both same-sex and opposite-sex couples) that HIV is untransmittable through condomless sexual intercourse if the HIV-positive partner has a consistently undetectable viral load.
Non-sexual transmission can occur from an infected mother to her infant during pregnancy, during childbirth by exposure to her blood or vaginal fluid, and through breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells.
HIV is a sexually transmitted infection (STI). It can also be spread by contact with infected blood or from mother to child during pregnancy, childbirth, or breast-feeding. Without medication, it may take years before HIV weakens your immune system to the point that you have AIDS.
Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body’s ability to fight infection and disease.
There’s no cure for HIV/AIDS, but medications can dramatically slow the progression of the disease. These drugs have reduced AIDS deaths in many developed nations.
The symptoms of HIV and AIDS vary, depending on the phase of infection.
Primary infection (Acute HIV)
Some people infected by HIV develop a flu-like illness within two to four weeks after the virus enters the body. This illness, known as primary (acute) HIV infection, may last for a few weeks. Possible signs and symptoms include:
- Muscle aches and joint pain
- Sore throat and painful mouth sores
- Swollen lymph glands, mainly on the neck
- Weight loss
- Night sweats
These symptoms can be so mild that you might not even notice them. However, the amount of virus in your bloodstream (viral load) is quite high at this time. As a result, the infection spreads more easily during primary infection than during the next stage.
Clinical latent infection (Chronic HIV)
In this stage of infection, HIV is still present in the body and in white blood cells. However, many people may not have any symptoms or infections during this time.
This stage can last for many years if you’re not receiving antiretroviral therapy (ART). Some people develop more severe diseases much sooner.
Symptomatic HIV infection
As the virus continues to multiply and destroy your immune cells — the cells in your body that help fight off germs — you may develop mild infections or chronic signs and symptoms such as:
- Swollen lymph nodes — often one of the first signs of HIV infection
- Weight loss
- Oral yeast infection (thrush)
- Shingles (herpes zoster)
Progression to AIDS
Thanks to better antiviral treatments, most people with HIV in the U.S. today don’t develop AIDS. Untreated, HIV typically turns into AIDS in about 8 to 10 years.
When AIDS occurs, your immune system has been severely damaged. You’ll be more likely to develop opportunistic infections or opportunistic cancers — diseases that wouldn’t usually cause illness in a person with a healthy immune system.
The signs and symptoms of some of these infections may include:
- Recurring fever
- Chronic diarrhea
- Swollen lymph glands
- Persistent white spots or unusual lesions on your tongue or in your mouth
- Persistent, unexplained fatigue
- Weight loss
- Skin rashes or bumps
HIV is caused by a virus. It can spread through sexual contact or blood, or from mother to child during pregnancy, childbirth, or breast-feeding.
How does HIV become AIDS?
HIV destroys CD4 T cells — white blood cells that play a large role in helping your body fight disease. The fewer CD4 T cells you have, the weaker your immune system becomes.
You can have an HIV infection, with few or no symptoms, for years before it turns into AIDS. AIDS is diagnosed when the CD4 T cell count falls below 200 or you have an AIDS-defining complication, such as a serious infection or cancer.
How HIV spreads
To become infected with HIV, infected blood, semen or vaginal secretions must enter your body. This can happen in several ways:
- By having sex. You may become infected if you have vaginal, anal, or oral sex with an infected partner whose blood, semen, or vaginal secretions enter your body. The virus can enter your body through mouth sores or small tears that sometimes develop in the rectum or vagina during sexual activity.
- By sharing needles. Sharing contaminated IV drug paraphernalia (needles and syringes) puts you at a high risk of HIV and other infectious diseases, such as hepatitis.
- From blood transfusions. In some cases, the virus may be transmitted through blood transfusions. American hospitals and blood banks now screen the blood supply for HIV antibodies, so this risk is very small.
- During pregnancy or delivery or through breast-feeding. Infected mothers can pass the virus on to their babies. Mothers who are HIV-positive and get treatment for the infection during pregnancy can significantly lower the risk to their babies.
How HIV doesn’t spread
You can’t become infected with HIV through ordinary contact. That means you can’t catch HIV or AIDS by hugging, kissing, dancing, or shaking hands with someone who has the infection.
HIV isn’t spread through the air, water, or insect bites.
Anyone of any age, race, sex, or sexual orientation can be infected with HIV/AIDS. However, you’re at greatest risk of HIV/AIDS if you:
- Have unprotected sex. Use a new latex or polyurethane condom every time you have sex. Anal sex is riskier than vaginal sex. Your risk of HIV increases if you have multiple sexual partners.
- Have an STI. Many STIs produce open sores on your genitals. These sores act as doorways for HIV to enter your body.
- Use IV drugs. People who use IV drugs often share needles and syringes. This exposes them to droplets of other people’s blood.
HIV infection weakens your immune system, making you much more likely to develop many infections and certain types of cancers.
Infections common to HIV/AIDS
- Pneumocystis pneumonia (PCP). This fungal infection can cause severe illness. Although it’s declined significantly with current treatments for HIV/AIDS, the U.S. PCP is still the most common cause of pneumonia in people infected with HIV.
- Candidiasis (thrush). Candidiasis is a common HIV-related infection. It causes inflammation and a thick, white coating on your mouth, tongue, esophagus, or vagina.
- Tuberculosis (TB). In resource-limited nations, TB is the most common opportunistic infection associated with HIV. It’s a leading cause of death among people with AIDS.
- Cytomegalovirus. This common herpes virus is transmitted in body fluids such as saliva, blood, urine, semen, and breast milk. A healthy immune system inactivates the virus, and it remains dormant in your body. If your immune system weakens, the virus resurfaces — causing damage to your eyes, digestive tract, lungs, or other organs.
- Cryptococcal meningitis. Meningitis is an inflammation of the membranes and fluid surrounding your brain and spinal cord (meninges). Cryptococcal meningitis is a common central nervous system infection associated with HIV, caused by a fungus found in soil.
- Toxoplasmosis. This potentially deadly infection is caused by Toxoplasma gondii, a parasite spread primarily by cats. Infected cats pass the parasites in their stools, which may then spread to other animals and humans. Toxoplasmosis can cause heart disease, and seizures occur when it spreads to the brain.
Cancers common to HIV/AIDS
- Lymphoma. This cancer starts in the white blood cells. The most common early sign is painless swelling of the lymph nodes in your neck, armpit, or groin.
- Kaposi’s sarcoma. A tumor of the blood vessel walls, Kaposi’s sarcoma usually appears as pink, red, or purple lesions on the skin and mouth. In people with darker skin, the lesions may look dark brown or black. Kaposi’s sarcoma can also affect the internal organs, including the digestive tract and lungs.
- Wasting syndrome. Untreated HIV/AIDS can cause significant weight loss, often accompanied by diarrhea, chronic weakness, and fever.
- Neurological complications. HIV can cause neurological symptoms such as confusion, forgetfulness, depression, anxiety, and difficulty walking. HIV-associated neurocognitive disorders (HAND) can range from mild symptoms of behavioral changes and reduced mental functioning to severe dementia causing weakness and inability to function.
- Kidney disease. HIV-associated nephropathy (HIVAN) is an inflammation of the tiny filters in your kidneys that remove excess fluid and wastes from your blood and pass them to your urine. It most often affects blacks or Hispanic people.
- Liver disease. Liver disease is also a major complication, especially in people who also have hepatitis B or hepatitis C.
There’s no vaccine to prevent HIV infection and no cure for AIDS. But you can protect yourself and others from infection.
To help prevent the spread of HIV:
- Use treatment as prevention (TasP). If you’re living with HIV, taking HIV medication can keep your partner from becoming infected with the virus. If you make sure your viral load stays undetectable — a blood test doesn’t show any virus — you won’t transmit the virus to anyone else. Using TasP means taking your medication exactly as prescribed and getting regular checkups.
- Use post-exposure prophylaxis (PEP) if you’ve been exposed to HIV. If you think you’ve been exposed through sex, needles, or in the workplace, contact your doctor or go to the emergency department. Taking PEP as soon as possible within the first 72 hours can greatly reduce your risk of becoming infected with HIV. You will need to take medication for 28 days.
- Use a new condom every time you have sex. Use a new condom every time you have anal or vaginal sex. Women can use a female condom. If using a lubricant, make sure it’s water-based. Oil-based lubricants can weaken condoms and cause them to break. During oral sex use a nonlubricated, cut-open condom or a dental dam — a piece of medical-grade latex.
- Consider preexposure prophylaxis (PrEP). The combination of drugs emtricitabine plus tenofovir (Truvada) and emtricitabine plus tenofovir alafenamide (Descovy) can reduce the risk of sexually transmitted HIV infection in people at very high risk. PrEP can reduce your risk of getting HIV from sex by more than 90% and from injection drug use by more than 70%, according to the Centers for Disease Control and Prevention. Descovy hasn’t been studied in people who have receptive vaginal sex.
- Your doctor will prescribe these drugs for HIV prevention only if you don’t already have an HIV infection. You will need an HIV test before you start taking PrEP and then every three months as long as you’re taking it. Your doctor will also test your kidney function before prescribing Truvada and continue to test it every six months. You need to take drugs every day. They don’t prevent other STIs, so you’ll still need to practice safe sex. If you have hepatitis B, you should be evaluated by an infectious disease or liver specialist before beginning therapy.
- Tell your sexual partners if you have HIV. It’s important to tell all your current and past sexual partners that you’re HIV-positive. They’ll need to be tested.
- Use a clean needle. If you use a needle to inject drugs, make sure it’s sterile and don’t share it. Take advantage of needle exchange programs in your community. Consider seeking help for your drug use.
- If you’re pregnant, get medical care right away. If you’re HIV-positive, you may pass the infection to your baby. But if you receive treatment during pregnancy, you can significantly cut your baby’s risk.
- Consider male circumcision. There’s evidence that male circumcision can help reduce the risk of getting HIV infection.
Consult with a doctor if you feel you may have been exposed to HIV.
HIV can be diagnosed through blood or saliva testing. Available tests include:
- Antigen/antibody tests. These tests usually involve drawing blood from a vein. Antigens are substances on the HIV virus itself and are usually detectable — a positive test — in the blood within a few weeks after exposure to HIV. Antibodies are produced by your immune system when it’s exposed to HIV. It can take weeks to months for antibodies to become detectable. The combination of antigen/antibody tests can take two to six weeks after exposure to become positive.
- Antibody tests. These tests look for antibodies to HIV in blood or saliva. Most rapid HIV tests, including self-tests done at home, are antibody tests. Antibody tests can take three to 12 weeks after you’re exposed to become positive.
- Nucleic acid tests (NATs). These tests look for the actual virus in your blood (viral load). They also involve blood drawn from a vein. If you might have been exposed to HIV within the past few weeks, your doctor may recommend NAT. NAT will be the first test to become positive after exposure to HIV.
Talk to your doctor about which HIV test is right for you. If any of these tests are negative, you may still need a follow-up test week to months later to confirm the results.
Tests to stage disease and treatment
If you’ve been diagnosed with HIV, it’s important to find a specialist trained in diagnosing and treating HIV to help you:
- Determine whether you need additional testing
- Determine which HIV antiretroviral therapy (ART) will be best for you
- Monitor your progress and work with you to manage your health
If you receive a diagnosis of HIV/AIDS, several tests can help your doctor determine the stage of your disease and the best treatment, including:
- CD4 T cell count. CD4 T cells are white blood cells that are specifically targeted and destroyed by HIV. Even if you have no symptoms, HIV infection progresses to AIDS when your CD4 T cell count dips below 200.
- Viral load (HIV RNA). This test measures the amount of virus in your blood. After starting HIV treatment the goal is to have an undetectable viral load. This significantly reduces your chances of opportunistic infection and other HIV-related complications.
- Drug resistance. Some strains of HIV are resistant to medications. This test helps your doctor determine if your specific form of the virus has resistance and guides treatment decisions.
Tests for complications
Your doctor might also order lab tests to check for other infections or complications, including:
- Hepatitis B or hepatitis C virus infection
- Liver or kidney damage
- Urinary tract infection
- Cervical and anal cancer
Currently, there’s no cure for HIV/AIDS. Once you have the infection, your body can’t get rid of it. However, there are many medications that can control HIV and prevent complications. These medications are called antiretroviral therapy (ART). Everyone diagnosed with HIV should be started on ART, regardless of their stage of infection or complications.
ART is usually a combination of three or more medications from several different drug classes. This approach has the best chance of lowering the amount of HIV in the blood. There are many ART options that combine three HIV medications into one pill, taken once daily.
Each class of drugs blocks the virus in different ways. Treatment involves combinations of drugs from different classes to:
- Account for individual drug resistance (viral genotype)
- Avoid creating new drug-resistant strains of HIV
- Maximize suppression of the virus in the blood
Two drugs from one class, plus a third drug from a second class, are typically used.
The classes of anti-HIV drugs include:
- Non-nucleoside reverse transcriptase inhibitors (NNRTIs) turn off a protein needed by HIV to make copies of itself. Examples include efavirenz (Sustiva), rilpivirine (Edurant), and doravirine (Pifeltro).
- Nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) are faulty versions of the building blocks that HIV needs to make copies of itself. Examples include abacavir (Ziagen), tenofovir (Viread), emtricitabine (Emtriva), lamivudine (Epivir), and zidovudine (Retrovir). Combination drugs also are available, such as emtricitabine/tenofovir (Truvada) and emtricitabine/tenofovir alafenamide (Descovy).
- Protease inhibitors (PIs) inactivate HIV protease, another protein that HIV needs to make copies of itself. Examples include atazanavir (Reyataz), darunavir (Prezista), and lopinavir/ritonavir (Kaletra).
- Integrase inhibitors work by disabling a protein called integrase, which HIV uses to insert its genetic material into CD4 T cells. Examples include bictegravir sodium/emtricitabine/tenofovir alafenamide fumar (Biktarvy), raltegravir (Isentress), and dolutegravir (Tivicay).
- Entry or fusion inhibitors block HIV’s entry into CD4 T cells. Examples include enfuvirtide (Fuzeon) and maraviroc (Selzentry).
Starting and maintaining treatment
Everyone with HIV infection, regardless of the CD4 T cell count or symptoms, should be offered antiviral medication.
Remaining on effective ART with an undetectable HIV viral load in the blood is the best way for you to stay healthy.
For ART to be effective, it’s important that you take the medications as prescribed, without missing or skipping any doses. Staying on ART with an undetectable viral load helps:
- Keep your immune system strong
- Reduce your chances of getting an infection
- Reduce your chances of developing treatment-resistant HIV
- Reduce your chances of transmitting HIV to other people
Staying on HIV therapy can be challenging. It’s important to talk to your doctor about possible side effects, difficulty taking medications, and any mental health or substance use issues that may make it difficult for you to maintain ART.
Having regular follow-up appointments with your doctor to monitor your health and response to treatment is also important. Let your doctor know right away if you’re having problems with HIV therapy so that you can work together to find ways to address those challenges.
Treatment side effects
Treatment side effects can include:
- Nausea, vomiting, or diarrhea
- Heart disease
- Kidney and liver damage
- Weakened bones or bone loss
- Abnormal cholesterol levels
- Higher blood sugar
- Cognitive and emotional problems, as well as sleep problems
Treatment for age-related diseases
Some health issues that are a natural part of aging may be more difficult to manage if you have HIV. Some medications that are common for age-related heart, bone, or metabolic conditions, for example, may not interact well with anti-HIV medications. It’s important to talk to your doctor about your other health conditions and the medications you’re taking.
If you are started on medications by another doctor, it’s important to let him or her know about your HIV therapy. This will allow the doctor to make sure there are no interactions between the medications.
Your doctor will monitor your viral load and CD4 T cell counts to determine your response to HIV treatment. These will be initially checked at two and four weeks, and then every three to six months.
Treatment should lower your viral load so that it’s undetectable in the blood. That doesn’t mean your HIV is gone. Even if it can’t be found in the blood, HIV is still present in other places in your body, such as in lymph nodes and internal organs.
Lifestyle and home remedies
Along with receiving medical treatment, it’s essential to take an active role in your own care. The following suggestions may help you stay healthy longer:
- Eat healthy foods. Make sure you get enough nourishment. Fresh fruits and vegetables, whole grains, and lean protein help keep you strong, give you more energy, and support your immune system.
- Avoid raw meat, eggs, and more. Foodborne illnesses can be especially severe in people who are infected with HIV. Cook meat until it’s well done. Avoid unpasteurized dairy products, raw eggs, and raw seafood such as oysters, sushi, or sashimi.
- Get the right vaccinations. These may prevent typical infections such as pneumonia and influenza. Your doctor may also recommend other vaccinations, including for HPV, hepatitis A, and hepatitis B. Inactivated vaccines are generally safe, but most vaccines with live viruses are not, due to your weakened immune system.
- Take care of companion animals. Some animals may carry parasites that can cause infections in people who are HIV-positive. Cat feces can cause toxoplasmosis, reptiles can carry salmonella, and birds can carry cryptococcus or histoplasmosis. Wash hands thoroughly after handling pets or emptying the litter box.
People who are infected with HIV sometimes try dietary supplements that claim to boost the immune system or counteract the side effects of anti-HIV drugs. However, there is no scientific evidence that any nutritional supplement improves immunity, and many may interfere with other medications you’re taking. Always check with your doctor before taking any supplements or alternative therapies to ensure there are no medication interactions.
Supplements that may be helpful
- Acetyl-L-carnitine. Researchers have used acetyl-L-carnitine to treat nerve pain, numbness, or weakness (neuropathy) in people with diabetes. It may also ease neuropathy linked to HIV if you’re lacking in the substance.
- Whey protein and certain amino acids. Early evidence suggests that whey protein, a cheese byproduct, can help some people with HIV gain weight. Whey protein also appears to reduce diarrhea and increase CD4 T cell counts. The amino acids L-glutamine, L-arginine, and hydroxymethyl butyrate (HMB) may also help with weight gain.
- Probiotics. There is some evidence that the probiotic Saccharomyces boulardii may help with HIV-related diarrhea but use only as directed by your doctor. Bovine colostrum is also being studied for treating diarrhea.
- Vitamins and minerals. Vitamins A, D, E, C, and B — as well as the minerals zinc, iron, and selenium — may be helpful if you have low levels of them.
Supplements that may be dangerous
- St. John’s wort. A common depression remedy, St. John’s wort can reduce the effectiveness of several types of anti-HIV drugs by more than half.
- Garlic supplements. Although garlic itself may help strengthen the immune system, garlic supplements may interact with some anti-HIV drugs and reduce their ability to work. Occasionally eating garlic in food appears to be safe.
- Red yeast rice extract. Some people use this to lower cholesterol, but avoid it if you take a protease inhibitor or a statin.
Practices such as yoga, meditation, and tai chi have been shown to reduce stress, as well as improve blood pressure and quality of life. While they need more study, these practices may be helpful if you’re living with HIV/AIDS.
Coping and support
Receiving a diagnosis of any life-threatening illness is devastating. The emotional, social, and financial consequences of HIV/AIDS can make coping with this illness especially difficult — not only for you but also for those closest to you.
But today, there are many services and resources available to people with HIV. Most HIV/AIDS clinics have social workers, counselors, or nurses who can help you directly or put you in touch with people who can.
Services they may provide:
- Arrange transportation to and from doctor appointments
- Help with housing and childcare
- Assist with employment and legal issues
- Provide support during financial emergencies
It’s important to have a support system. Many people with HIV/AIDS find that talking to someone who understands their disease provides comfort.
What to expect from your doctor
Your doctor will ask you questions about your health and lifestyle. Your doctor will perform a complete physical exam, checking you for:
- Swollen lymph nodes
- Lesions on your skin or in your mouth
- Problems with your nervous system
- Abnormal sounds in your lungs
- Swollen organs in your abdomen
- HIV is a lifelong infection, but it is treatable and can be controlled with medications. With consistent treatment using highly specialized antiviral medications, a person with HIV may live about as long as an uninfected person.
- Statistics show that approximately 40 million people are currently living with HIV infection, and an estimated 40 million have died from this disease since the beginning of the epidemic. HIV has been particularly devastating in sub-Saharan Africa, which accounts for almost 70% of new HIV infections globally. However, infection rates in other countries also remain high.
- Globally, 85% of HIV transmission is through heterosexual intercourse.
- Worldwide, almost half of people with HIV are women, whereas, in the United States, male-to-male sexual contact still accounts for more than 60% of new diagnoses.
- Approximately 20% of new diagnoses are in women. In the United States, heterosexual transmission accounts for approximately one-quarter of new diagnoses, with intravenous drug use contributing to the remaining cases in the U.S.
Number of People with HIV—There were approximately 38 million people across the globe with HIV/AIDS in 2019. Of these, 36.2 million were adults and 1.8 million were children (<15 years old).
New HIV Infections—An estimated 1.7 million individuals worldwide acquired HIV in 2019, marking a 23% decline in new HIV infections since 2010. (New HIV infections, or “HIV incidence,” refers to the estimated number of people who newly acquired the HIV virus during a given period such as a year, which is different from the number of people diagnosed with HIV during a year. (Some people may have HIV but not know it.) Of these new infections:
- 1.5 million were among adults
- 150,000 infections were among children (<15 years old)
However, progress in the prevention of HIV transmission remains far too slow, with the estimated total number of new infections in 2019 more than three times higher than UNAIDS’s 2020 target.
Mother-to-Child Transmission—In 2019, 85% of pregnant women with HIV received ART to prevent transmitting HIV to their babies during pregnancy and childbirth and to protect their own health.
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