Disease: HIV/AIDS

What Is HIV?

HIV is a difficult-to-treat virus that impairs the immune system's ability to fight infections and diseases.

The human immunodeficiency virus, or HIV, is a virus that attacks the body’s immune system.

Specifically, the virus infects people's CD4-positive (CD4+) T-helper cells.

Those cells — sometimes known as CD4 cells, T-helper cells, or T4 cells — are white blood cells that play an important role in the immune system.

Over time, HIV can destroy CD4 cells, impairing the immune system's ability to fight off infections and diseases.

The final stage of an HIV infection is called acquired immunodeficiency syndrome, or AIDS.

AIDS is a life-threatening disease, and occurs when your immune system is severely damaged.

AIDS is usually diagnosed when your CD4 cells are very low or when you develop one or more opportunistic illnesses, such as pneumonia or tuberculosis, as a result of an HIV infection and a compromised immune system.

HIV/AIDS Prevalence and Demographics

In the United States, there are about 50,000 new cases of HIV each year, according to the Centers for Disease Control and Prevention (CDC).

The CDC further estimates that some 1.2 million Americans were living with HIV in 2011, and about 14 percent of these people (168,000) didn't even know they were infected.

The devastating virus doesn't affect different groups of people equally. Of the estimated 47,500 new U.S. cases of HIV in 2010, about two-thirds of the newly infected people were bisexual or gay men, according to CDC data.

Different races and ethnicities also experience skewed HIV infection rates.

In 2010, African-Americans, whites, and Hispanic/Latinos accounted for 44, 31, and 21 percent of new HIV cases in the United States, respectively.

Despite improved treatment options available since the AIDS outbreak in the 1980s, people still die from the disease.

In 2012, AIDs caused the death of 13,712 people in the United States, bringing the total AIDS death toll in the country to 658,507 people, according to the CDC.

HIV/AIDS Worldwide

Globally, HIV and AIDS are still a serious problem, with an estimated 2.1 million new cases of HIV and 35 million people living with the virus in 2013, according to the CDC.

Today, people in sub-Saharan Africa bear the brunt of the current HIV epidemic, accounting for nearly 71 percent of people living with HIV worldwide, according to the World Health Organization (WHO).

What's more, about 1 in 20 adults in sub-Saharan Africa have HIV.

Since the epidemic began decades ago, HIV has infected approximately 78 million people, and about 39 million people with AIDS have died, WHO notes.

HIV Transmission and Prevention

Blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk can transmit HIV between people.

For someone to get HIV, however, infected fluids must be injected directly into the bloodstream, or come in contact with damaged tissue (cuts) or the mucous membranes in the vagina, opening of the penis, rectum, and mouth.

In the United States, HIV is mostly spread through sex — particularly anal and vaginal — with an infected person. The disease is also transmitted through sharing contaminated needles and other paraphernalia for intravenous drug use.

You can reduce your risk of getting HIV if you:

  • Never share needles
  • Use condoms correctly and consistently
  • Limit your number of sexual partners
  • Choose less risky sexual behaviors (oral sex instead of anal or vaginal sex, for instance)
  • Get checked and treated for other sexually transmitted diseases

A drug called pre-exposure prophylaxis, or PrEP, can greatly reduce your risk of becoming infected with HIV — by up to 92 percent, according to the CDC — if it's taken every day.

Another medication called post-exposure prophylaxis (PEP) can reduce your risk of becoming infected with HIV if taken within three days of exposure to the virus.

Sources:

  • HIV/AIDS; National Institute of Allergy and Infectious Diseases
  • HIV/AIDS Basic Statistics; CDC
  • Prevalence of HIV among adults aged 15–49 (%); World Health Organization
  • HIV Transmission; CDC
  • HIV Prevention; CDC
  • HIV/AIDS, PrEP; CDC

HIV Symptoms

Initially, HIV may cause symptoms that are often described as the "worst flu ever."

HIV (human immunodeficiency virus) is a dangerous infection that can leave people vulnerable to other infections and diseases, especially if the HIV infection has progressed to its final stage — AIDS, or acquired immunodeficiency syndrome.

In 2011, 1.2 million people in the United States were living with HIV, according to the Centers for Disease Control and Prevention (CDC).

Alarmingly, an estimated 14 percent of HIV-positive people in 2011 didn't know they had it, the CDC notes.

This is partly because the virus initially only produces symptoms that could easily be confused with other health issues, if it causes any symptoms at all.

In fact, some people go 10 years or more without having any HIV-related symptoms after contracting the virus.

Early Stage Symptoms

Many people experience flu-like symptoms within two to four weeks after contracting HIV.

Known as acute retroviral syndrome (ARS) or primary HIV infection, these symptoms are the body's natural response to the HIV infection.

Symptoms include:

  • Fever, the most common symptom
  • Enlarged lymph nodes in the neck, armpits and groin area (swollen glands)
  • Sore throat
  • Mouth sores, including thrush (yeast infection)
  • Various types of rashes
  • Fatigue
  • Aches and pains in the muscles and joints
  • Headache
  • Diarrhea
  • Night sweats

Some people describe ARD as the "worst flu ever," according to AIDS.gov.

Clinical Latency Stage

The symptoms during ARS last between a few days and several weeks, according to the CDC.

After this point, the infection progresses to the clinical latency stage, a period during which the virus reproduces at very low levels, but is still active.

Also known as asymptomatic HIV infection or chronic HIV infection, the clinical latency stage typically causes no HIV-related symptoms.

For people who are not taking any antiviral medications for their infection, the clinical latency stage lasts for 10 years, on average, but it may progress quicker.

However, antiretroviral therapy and highly active antiretroviral therapy can keep the virus from growing and multiplying, prolonging the clinical latency state for several decades.

It's important to note that people living with HIV in the clinical latency stage can still transmit the virus to other people.

AIDS Symptoms

The final stage of an HIV infection is AIDS, which occurs when the immune system is severely damaged. It's diagnosed when your CD4 cells (also called T-helper cells or T-4 cells) are very low or when you develop one or more opportunistic illnesses, such as pneumonia or tuberculosis, as a result of an HIV infection.

People with AIDS may experience:

  • Rapid weight loss
  • Recurring fever
  • Profuse night sweats
  • Pronounced fatigue and weakness
  • Prolonged swollen lymph glands
  • Chronic diarrhea, which lasts more than a week
  • Sores that develop in the mucous membranes of the mouth, anus, or genitals
  • Blotches (red, brown, pink, or purplish) on the skin, under the skin, or inside the mouth, nose, or eyelids
  • Neurological issues, including memory loss and depression

Many of these symptoms, particularly those that are severe, may be related to other opportunistic infections that develop due to the weakened immune system.

These opportunistic infections can include tuberculosis, pneumonia, and candidiasis (yeast infections).

Sources:

  • HIV/AIDS; MedlinePlus/NIH
  • HIV/AIDS, Symptoms; National Institute of Allergy and Infectious Diseases
  • Signs and Symptoms; AIDS.gov
  • Opportunistic Infections; AIDS.gov
  • About HIV/AIDS; CDC

HIV Transmission and Risk Factors

In the United States, HIV is mostly transmitted through anal sex, vaginal sex, and the sharing of needles.

Acquired immunodeficiency syndrome, or AIDS, is the final stage of an infection by the human immunodeficiency virus (HIV).

When the HIV virus gets into the human body, it infects certain immune system cells called T helper cells or CD4 cells.

The virus replicates itself and, over time, damages its host cells, impairing the body's ability to fight off infections and diseases.

If you have HIV, you can be diagnosed with AIDS if your CD4 cell count is very low — fewer than 200 cells per cubic millimeter, compared with the normal count of 500 to 1,600 cells per cubic millimeter — or if you develop one or more opportunistic illnesses from your infection, such as tuberculosis, according to the Centers for Disease Control and Prevention (CDC).

How HIV Is Transmitted

To contract HIV, certain bodily fluids infected with the virus must enter your bloodstream directly, or come into contact with damaged tissue or the mucous membranes of your rectum, vagina, opening of the penis, or mouth.

Fluids that can transmit HIV include:

  • Blood
  • Semen ("cum")
  • Pre-seminal fluid ("pre-cum")
  • Rectal fluids
  • Vaginal fluids
  • Breast milk

In the United States, HIV is most commonly transmitted via anal or vaginal sex, and the sharing of contaminated needles, syringes, and other equipment for the injection of drugs, such as heroin, steroids, and hormones.

Though uncommon, the virus can also be transmitted by:

  • An infected mother to her infant through pregnancy, birth, or breastfeeding
  • Oral sex, especially if it involves ejaculation in the mouth
  • Infected blood from mouth sores and bleeding gums, such as through "deep" open-mouth kissing, biting that breaks the skin, and eating food that's been pre-chewed by an HIV-positive person
  • HIV-contaminated needles and objects that puncture the skin, especially needle-stick injuries in the healthcare setting
  • Blood and clotting factor transfusions, and organ and tissue transplants (mostly an issue outside of the United States)

HIV Risk Factors

According to the National Institute of Allergy and Infectious Diseases, you may be at increased risk for contracting HIV if you:

  • Have a sexually transmitted disease, such as syphilis, genital herpes, chlamydia, or gonorrhea
  • Have been diagnosed with hepatitis, tuberculosis, or malaria
  • Received a blood transfusion, clotting factor, or organ or tissue transplant in the United States between 1978 and 1985
  • Engage in unprotected anal, vaginal, or oral sex, especially with multiple partners or anonymous partners
  • Have sex in exchange for drugs or money
  • Share needles and other equipment for injecting drugs

In terms of risks associated with different sex practices, receptive anal intercourse (bottoming) carries the most risk, followed by insertive anal intercourse and receptive penile-vaginal intercourse, according to the CDC.

Certain other sexual practices, including rimming (oral-anal contact), fingering (digital stimulation), and sharing sex toys carry very low — but not zero — risk of transmitting HIV.

Groups with Higher HIV Risk

Though the above risk factors are the same for everyone, HIV affects certain demographical groups more than others.

For instance, bisexual and gay men accounted for almost two-thirds of new HIV cases in 2010, according to the CDC.

Additionally, African-Americans accounted for 44 percent of new cases in 2010 — the highest percentage for any racial group. Whites and Hispanic/Latinos accounted for 31 and 21 percent of new cases that same year, respectively.

Youths tend to have the highest HIV diagnosis rates.

In 2013, people age 13 to 24 accounted for 21 percent of the people diagnosed with HIV.

About 81 percent of the diagnoses in this age group occurred in people between 20 and 24 years old.

Sources:

  • HIV Transmission Risk; CDC
  • HIV/AIDS Transmission; NIAID
  • Lower Your Sexual Risk of HIV; AIDS.gov
  • Who Is at Risk for HIV?; AIDS.gov
  • HIV Transmission; CDC
  • HIV Among Youth; CDC

HIV/AIDS Tests and Diagnosis

Some HIV screening tests can detect signs of HIV infection within 20 minutes.

An estimated one in seven HIV-positive people in the United States don't know they are infected with the virus because they haven't been tested for it, according to the Centers for Disease Control and Prevention (CDC).

It's important to get tested regularly for HIV because you can't rely on HIV-related signs and symptoms as an accurate predictor of your HIV status.

In fact, after contracting the virus, some people live for 10 years or more before experiencing any symptoms.

Who Should Get Tested?

Unsafe sex practices and intravenous drug use put you at risk of contracting HIV.

The CDC recommends you get tested for HIV if you recently:

  • Had sex with an HIV-positive person, or someone with an unknown HIV status
  • Shared needles, syringes, and other equipment for injecting drugs — including heroin, steroids, hormones, and silicon — with other people
  • Had sex for drugs or money
  • Had been diagnosed with or treated for other sexually transmitted diseases, which increase your risk of contracting HIV
  • Had been diagnosed or treated for hepatitis or tuberculosis, which are common diseases in people with HIV
  • Had been sexually assaulted

You should also get tested if you are a woman planning to get pregnant or already pregnant.

If you're having unsafe sex or sharing drug injection needles, you should get tested for HIV at least once a year, the CDC says.

Sexually active gay and bisexual men may want to get tested every three to six months, considering that this demographic accounted for almost two-thirds of the new U.S. HIV cases in 2010, the agency notes.

Initial HIV Tests

Screening tests for HIV look for either HIV antibodies (proteins your body makes to fight the virus), or both antibodies and antigens (substances found on the viruses that trigger the production of antibodies).

Enzyme-linked immunosorbent assay (ELISA) is the most commonly used screening test for HIV.

Early-generation antibody screening tests can detect HIV antibodies six to 12 weeks after infection. The tests are performed on blood or oral fluid (cheek swabs), with the blood tests being able to find the virus sooner after exposure than oral fluid tests.

The antibody/antigen screening tests are performed only on blood, and can detect the virus as soon as three weeks after infection.

Rapid antibody tests that can give results on the spot (rather than requiring laboratory processing) are also available, though they're less sensitive than the laboratory tests.

These tests use blood or oral fluid, and provide results in less than 20 minutes — some in as little as two minutes.

In the United States, you can purchase two at-home HIV screening tests: the Home Access HIV-1 Test System and the OraQuick In-home HIV test.

The former requires you to prick your finger and send a blood sample off to a lab; the latter requires a mouth swab and can provide results within 20 minutes, though up to one in 12 people may received a false-negative result, according to the CDC.

Follow-up Diagnostic Tests

Aside from antibody and antigen tests, another HIV-detection tool is the RNA test, a type of blood test that can detect genetic material from HIV about 10 days after infection.

Due to its high cost, however, it's generally not used as a screening test, but may be used as a follow-up test to confirm diagnosis.

Though HIV tests are pretty accurate, follow-up blood tests are necessary to confirm a positive HIV diagnosis.

Aside from the RNA test, these include:

  • Antibody differentiation test, which distinguishes between HIV-1 and HIV-2 (HIV-2 is less prevalent and disease-causing than HIV-1)
  • Western blot and indirect immunofluorescence assay, which are highly sensitive tests that detect antibodies

Sources:

  • HIV Antibody Assays; HIV InSite/UCSF
  • Advantages and disadvantages of FDA-approved HIV immunoassays used for screening by generation and platform; CDC
  • HIV Testing; CDC
  • HIV Testing: Get the Basics; Aids.gov
  • HIV/AIDS; MedlinePlus
  • Home Tests; CDC

HIV Treatment

There are six classes of drugs that interfere with HIV's ability to replicate.

In 1981, the first known case of AIDS — the final stage of an HIV infection — was reported.

Six years later, in 1987, the Food and Drug Administration (FDA) approved the first drug for the treatment of AIDS: zidovudine or azidothymidine (AZT).

Today, there are more than 30 FDA-approved drugs for the treatment of HIV/AIDS.

However, there is no drug currently available that can rid the body of HIV, curing the viral infection.

Instead, the medications suppress the virus by interfering with its ability to replicate in the body.

There are also two drugs available that can prevent you from contracting HIV:

  • Pre-exposure prophylaxis, or PrEP, which greatly reduces your risk of becoming infected with HIV when taken every day
  • Post-exposure prophylaxis, or PEP, which reduces your risk of becoming infected if you take it within three days of being exposed to HIV

Classes of Antiretroviral Drugs

There are six classes of antiretroviral drugs for HIV, each of which act on a different step in HIV's replication cycle.

People generally take three drugs from two different classes, which help to better control the virus and prevent it from developing drug resistance.

This "cocktail" treatment is called antiretroviral therapy (ART), or highly active antiretroviral therapy (HAART).

The classes of drugs include:

  • Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (Retrovir), abacavir (Ziagen), and emtricitabine (Emtriva), which block reverse transcriptase, an enzyme the virus needs to convert single-stranded HIV RNA into double-stranded HIV DNA
  • Non-nucleoside reverse transcriptase inhibitors(NNRTIs), such as efavirenz (Sustiva), etravirine (Intelence), and nevirapine (Viramune), which bind to and alter reverse transcriptase
  • CCR5 antagonists (also called entry inhibitors), such as maraviroc (Selzentry), which blocks CCR5, a receptor protein on the surface of CD4 cells (immune system cells) that the virus binds to in order to enter the cell
  • Fusion inhibitors, such as enfuvirtide (Fuzeon), which also blocks HIV's ability to enter CD4 cells
  • Protease inhibitors, such as atazanavir (Reyataz), ritonavir (Norvir), and tipranavir (Aptivus), which block protease, an enzyme HIV needs to replicate and infect new cells
  • Integrase strand transfer inhibitors (INSTIs), such as dolutegravir (Tivicay), elvitegravir (Vitekta), and raltegravir (Isentress), which block integrase, an enzyme the virus uses to integrate its genetic material into its host cell's DNA

There are also fixed-dose combination antiretroviral medications — single pills that contain multiple drugs.

Additionally, pharmacokinetic enhancers, such as cobicistat (Tybost), can increase the effectiveness of the antiretroviral drugs (though they have no effect on the virus when used alone).

Medication Side Effects

Side effects and complications of the various HIV medications can include:

  • Anemia, an abnormality in red blood cells
  • Diarrhea
  • Headache and dizziness
  • Fatigue
  • Nausea and vomiting
  • Pain
  • Nerve problems
  • Rash
  • Unusual fat loss or fat buildup (lipodystrophy)
  • Insulin resistance and increased levels of blood glucose (hyperglycemia)
  • Bone lose
  • Lactic acidosis, a buildup of lactic acid in the bloodstream
  • Swelling of the mouth or tongue
  • Liver damage

Drug Interactions

It's important to discuss all of the medications and supplements you're taking with your doctor because antiretroviral drugs can interact with a wide range of other medications.

These include but are not limited to:

  • Acid-reducing agents and acid reflux medications, including antacids, proton pump inhibitors, and H2 antagonists
  • Drugs and supplements that affect p-glycoprotein or the enzyme CYP3A4, such as St. John's wort
  • Substances that affect the activity of the enzyme cytochrome P450, such as grapefruit juice

Sources:

  • HIV/AIDS Historical Time Line 1981-1990; FDA
  • Drugs That Fight HIV-1; NIAID
  • Types of HIV/AIDS Antiretroviral Drugs; NIAID
  • Overview of HIV Treatments; AIDS.gov
  • HIV Treatment: The Basics; AIDSinfo
  • Side Effects of Anti-HIV Medications; AIDSinfo
  • Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents; AIDSinfo

HIV/AIDS Complications

People with AIDS may experience a wide range of opportunistic infections.

In 2012, AIDS — the final stage of an HIV infection — caused 13,712 deaths in the United States, according to the Centers for Disease Control and Prevention (CDC).

Overall, more than 658,500 people in the United States with an AIDS diagnosis have died, the CDC reports.

On its own, HIV, which infects a vital immune system cell called the CD4 cell, doesn't produce many life-threatening symptoms.

What makes it so dangerous, however, is that the virus ultimately destroys CD4 cells, weakening the immune system and making the body vulnerable to deadly opportunistic infections and diseases — a sign that AIDS has taken hold.

HIV Infection-Related Complications

People living with HIV/AIDS are at a high risk of becoming infected by a wide range of different viruses and microbes, including bacteria, fungi, and parasites.

According to the CDC, the most common opportunistic infections that people with HIV/AIDS experience include:

  • Candidiasis, an infection by yeast in the genus Candida, which in serious cases can affect the esophagus, trachea, bronchi, and deeper lung tissues
  • Coccidioidomycosis, an infection by the fungus Coccidioides immitis, which can cause a form of pneumonia sometimes called desert fever, San Joaquin Valley fever, or Valley fever
  • Cryptococcosis, an infection by the fungus Cryptococcus neoformans, which first affects the lungs (causing pneumonia) and brain (causing swelling), before spreading to the skin, bones, and urinary tract
  • Cryptosporidiosis, and infection and diarrheal disease caused by the protozoan parasite Cryptosporidium
  • Cytomegalovirus infections that can cause pneumonia, gastroenteritis (stomach and intestine inflammation), encephalitis (brain inflammation), and retinitis (an infection of the retina that can cause blindness)
  • Herpes simplex virus infections, which can cause bronchitis, pneumonia, and esophagitis
  • Histoplasmosis, a lung infection by the fungus Histoplasma capsulatum that causes flu- and pneumonia-like symptoms as well as progressive disseminated histoplasmosis, a disease that can affect other organs
  • Isosporiasis, a chronic intestinal infection by the parasite Isospora belli
  • Tuberculosis, which is caused by the bacteria Mycobacterium tuberculosis
  • Systemic (affecting the whole body) diseases by the bacteria Mycobacterium avium, M. intracellulare, and M. kansasii
  • Pneumocystis jiroveci pneumonia, or PJP
  • Pneumonia caused by Streptococcus pneumoniae
  • Progressive multifocal leukoencephalopathy, a brain and spinal cord (central nervous system, or CNS) disease caused by the JC virus
  • Septicemia (blood infection) by the bacteria Salmonella
  • Toxoplasmosis, a brain infection by the parasite Toxoplasma gondii

Neurological Complications

As virus-related inflammation damages the CNS, people with HIV/AIDS may experience various symptoms such as confusion, forgetfulness, behavioral issues, headaches, weakness, and numbness in the extremities.

What's more, complications from the virus or drugs to treat it can include:

  • Pain
  • Seizures
  • Shingles
  • Spinal cord problems
  • Coordination issues and gait disorders
  • Problems with swallowing
  • Anxiety
  • Depression
  • Fever
  • Vision loss
  • Coma

In addition to the infections listed above, people with HIV/AIDS are vulnerable to other viruses and microbes that affect the CNS, including Cryptococcus neoformans, which causes Cryptococcal meningitis, and Treponema pallidum, which causes neurosyphilis, according to the National Institute of Neurological Disorders and Stroke (NINDS).

Other neurological complications unrelated to infections are also possible, such as AIDS dementia complex, HIV-associated dementia, CNS lymphomas, neuropathies (nerve disorders), vacuolar myelopathy (a spinal cord condition), and various psychological and neuropsychiatric disorders.

Other Complications

People with HIV/AIDS may also experience:

  • Lymphomas, or cancers of the lymph nodes
  • Kaposi's sarcoma, a kind of blood vessel cancer caused by Kaposi's sarcoma herpesvirus (KSHV) or human herpesvirus 8 (HHV-8)
  • Wasting syndrome, which is the involuntary loss of at least 10 percent body weight (mostly from muscle mass) that’s often accompanied by diarrhea, weakness, and fever
  • Kidney disease, or HIV-associated nephropathy

Sources:

  • HIV/AIDS Opportunistic Infections; CDC
  • Neurological Complications of AIDS Fact Sheet; National Institute of Neurological Disorders and Stroke
  • Opportunistic Infections; Aids.gov
  • HIV/AIDS Complications; Mayo Clinic

Source: http://www.everydayhealth.com

Define Common Diseases

Welcome to WebHealthNetwork, here you can find information, definitaions and treatement options for most common diseases, sicknesses, illnesses and medical conditions. Find what diseases you have quick and now.