AIDS and HIV: The human immunodeficiency virus (HIV) causes AIDS, also known as acquired immunodeficiency syndrome (HIV). HIV is a lentivirus (literally, “slow virus”; a retrovirus family member) that targets and destroys the immune system, the body’s defence against infection, leaving a person susceptible to a range of other infections and cancers that can lead to death. AIDS is the last stage of HIV infection, and it is during this time that deadly infections and malignancies are most common. Read this article to learn about the history, structural details of the AIDS virus and also about its symptoms, treatment and prevention!

What is HIV?

Fig: HIV

HIV stands for Human Immunodeficiency Virus. If not treated, the virus causes acquired immunodeficiency syndrome or AIDS. Unlike certain other viruses, HIV cannot be entirely eradicated by the human body, even with good therapy. As a result, once you get HIV, you will be infected for the rest of your life.

Etiology

HIV is a member of the Lentivirus genus, which belongs to the Retroviridae family. Many morphologies and biological features are similar to lentiviruses. Lentiviruses infect a wide range of organisms and are typically responsible for long-term diseases with a prolonged incubation period.

Types of HIV

There are two types of HIV strains:

The most frequent form of virus detected around the world is HIV-1.

1. Group M: The letter ‘M’ stands for ‘Major,’ implying that this group of HIV is responsible for 90% of all HIV-related AIDS worldwide. There are 11 subtypes of viruses in this group (A to K).
2. The letter ‘N’ stands for “non-M and non-O.” Only ten Group N illnesses had been identified as of 2006, according to the statistics.
3. In Group O, the letter’ O’ stands for the HIV’ Outlier’ category. Outside of west-central Africa, this virus is rarely found.
4. Group P: This virus was only recently discovered in 2009. So far, only one case of the group-P virus has been discovered. Because only simians were afflicted by the virus (apes and monkeys). However, a viral strain was discovered by a Cameroonian woman.

HIV-2 is predominantly common in Western Africa, but it has also been detected in India and Europe. There are eight HIV-2 subtypes that have been identified (A to H). The simian immunodeficiency virus, which is endemic in a monkey species, is identical to HIV-2 (sooty mangabeys).

What is AIDS?

It’s a dysfunction with the body’s cell-mediated immune system. The amount of helper T cells, which boost B-cell antibody production, is decreasing. As a result, the body’s natural defences against viral infection are hindered.

Discovery of Acquired Immunodeficiency Syndrome

1. AIDS was first detected in the United States in 1981 among homosexuals. The first human retrovirus was found by Robert Gallo and his colleagues at the National Cancer Institute in the United States. In the late 1970s, they discovered the human T- cell lymphotropic virus type I (HTLV-I), a virus that causes leukaemia (blood cancer) but not AIDS.
2. Professor Luc Montagnier and colleagues at the Institute Pasteur in Paris discovered the AIDS virus in 1983. The virus was given the label lymphadenopathy-associated virus (LAV).
3. In 1986, AIDS infections were discovered for the first time in India, in the prostitutes of Chennai, Tamil Nadu.
4. In 1986, the International Committee on Viral Diseases designated the AIDS virus Human Immunodeficiency Virus (HIV). In 2008, Francoise Barre-Sinoussi and Luc Montagnier were awarded the Nobel Prize for Physiology or Medicine for their discovery that HIV infection causes AIDS.
5. Francoise Barre-Sinoussi and Luc Montagnier were given the Nobel Prize for Physiology or Medicine in 2008 for discovering that HIV infection causes AIDS.
6. During the 1960s, the AIDS virus may have spread from a monkey host to the human population in Africa.
7. South Africa is known as the “AIDS capital of the world.”

Mechanism of HIV Action

The virus was first detected and termed HCLV III (Human cell leukaemia virus III) by Americans. However, the virus’s name was changed to HIV (Human immunodeficiency virus). HIV is a retrovirus that targets helper cells T cells.

Fig: Mechanism of HIV Action

The human immunodeficiency virus (HIV) is a virus that targets the immune system of the body. T helper cells (Th cells), also known as CD4+ cells or CD4-positive cells, are targeted by the virus. These unique cells aid the immune system in its fight against illness. HIV lowers the amount of CD4 cells (T-cells) in the body if left untreated. HIV can damage so many of these cells over time that the body is unable to fight infections and disease. T Helper cells activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

Damaged T-cells are thus unable to stimulate B-cells which normally multiply and produce antibodies that attack the invading virus. Furthermore, this immune system dysfunction makes it difficult for the body to fight infections and other disorders. If HIV is not treated, it can progress to AIDS (acquired immunodeficiency syndrome), which makes infections and malignancies more likely to take advantage of a weakened immune system.

Fig: Structure of HIV

Structure of HIV

The virus has a spherical shape and a diameter of 90-120 nm. It has a single-stranded RNA filament that is segmented into two identical filaments and is linked to a reverse transcriptase enzyme. A lipid bilayer produced from the host cell membrane and protruding knobs resembling glycoprotein spikes makes up the envelope. It has two protein coatings on it.

Mode of Action of AIDS Virus

Fig: Mode of Action of AIDS Virus

1. After entering the body of the individual, the virus enters macrophages, where the virus’s RNA genome replicates to synthesize viral DNA with the help of the reverse transcriptase enzyme.
2. The viral DNA is incorporated into the DNA of the infected cells, directing them to produce viruses.
3. Macrophages operate as an HIV factory, producing viruses. During this time, the HIV virus replicates and produces additional viruses in helper T cells.
4. To begin with, the reverse transcriptase enzyme converts RNA to cDNA.
5. The c DNA is then replicated into double-stranded DNA.
6. This dsDNA, together with the integrase enzyme, enters the nucleus of host cells via nucleopores.
7. Integrase enzymes function as molecular scissors, cutting the host DNA at certain sequences and assisting in the attachment OR integration of viral secondary DNA into the host DNA strand.
8. With the help of RNA polymerase, it is then translated into viral m RNA and released into the cytoplasm, where it is transcribed into new envelope proteins and the viral genome by the ribosome.
9. Surface proteins migrate into the cell, and other proteins congregate at the cell surface.
10. The polynucleotide is subsequently broken into distinct proteins by the protease enzyme, and the viral proteins are assembled. The new viral progeny was then liberated and was ready to attack more cells.
11. The process is repeated until the quantity of T cells in the infected person’s body is reduced.
12. The infected person experiences fever, diarrhoea, and weight loss during this time. 
13. As the number of helper T cells in the body diminishes, the person begins to feel ill—infections with bacteria, particularly Mycobacterium, viruses, fungi, and even parasites such as Toxoplasma.
14. The patient develops an immunological deficit and is unable to defend himself against infections.

Transmission of Acquired Immunodeficiency Syndrome

The virus of AIDS is transmitted via blood and semen
(i) Transfusion of infected blood or blood products
(ii) Use of contaminated needles and syringes to inject drugs or vaccines
(iii) Use of contaminated razors
(iv) Use of contaminated needles for boring pinnae
(v) Sexual intercourse with an infected partner without a condom
(vi) From infected mother to child through the placenta
(vii) Artificial insemination
(viii) Organ transplant.

Incubation period

The incubation period of AIDS ranges between 6 months to 10 years.

Symptoms

It takes roughly ten years for HIV to develop into HIV/AIDS if it is left untreated. Symptoms of the immune system’s continuous damage, such as recurrent fever, persistent and severe lethargy, chronic diarrhoea, and neurological diseases like depression and memory loss, may appear at this time.

Fig: The last Stage of HIV- Acquired Immunodeficiency Syndrome Symptoms

Other notable symptoms that may appear at this period are:

1. Swollen lymph glands: Lymphadenopathy, which commonly appears on the neck, below or behind the ear, or under the armpit in severe cases, can be uncomfortable and ugly. Persistent generalized lymphadenopathy is defined as nodes that develop larger than 2 cm (about an inch) and last longer than three months (PGL). It could take months or even years to get to the bottom of this.
2. Candidiasis (thrush): This fungal infection is frequently a precursor to disease. Candida can appear in the mouth, throat, or vaginal area; however, it is most usually detected in the mouth. Candidiasis is most common in patients with low CD4 levels (less than 200 cells/mL). Candidiasis is so common in persons with advanced HIV that if it affects the bronchi, trachea, oesophagus, or lungs, it’s now regarded as an AIDS-defining illness.
3. Skin issues include red, pink, brown, or purplish blotches on or under the skin, or inside the mouth, nose, or eyelids; white spots or strange mouth or tongue lesions; and sores on the anus or genitals.
4. Sleep hyperhidrosis: Unexplained, drenching night sweats may indicate a dangerous HIV-related illness such as tuberculosis, Mycobacterium avium complex, or histoplasmosis.
5. Extreme weight loss (HIV wasting): HIV wasting is defined as a sudden, unexplained loss of at least 10% of body weight for a period of 30 days or more, especially when accompanied by fever and diarrhoea.

The AIDS-Related Complex (ARC) is a term that refers to a mild form of the condition. Swollen lymph nodes, fever, nocturnal sweating, and weight loss are all signs. Patients with ARC have a greater risk of developing AIDS in their early years. Prodromal AIDS is another name for ARC (symptoms before AIDS).

Diagnosis of Acquired Immunodeficiency Syndrome

ELISA and Western Blotting tests can both be used to diagnose AIDS. For confirmation of ELISA positive cases, the western blotting test is used.

Treatment of AIDS

Although there is no cure for AIDS, many medications can help AIDS patients live longer. The first medicine used to treat AIDS was zidovudine, also known as AZT (azidothymidine). It is still the drug of choice today. Another medicine used to treat AIDS is didanosine (dideoxyinosine, DDI).

Prevention (Prophylaxis) of Acquired Immunodeficiency Syndrome

Until now, no vaccine against the AIDS virus has been developed. The steps below may prevent the occurrence of AIDS.

(i) AIDS education should be provided to the general public. Every year on December 1st, World AIDS Day is commemorated. It’s one of the ways to raise awareness about AIDS.
(ii) Blood tests must be performed on blood donors, sperm donors, organ donors (kidney, lung, liver), haemodialysis patients, and pregnant women.
(iii) Only use disposable needles and syringes. Needles and syringes that have been used must be disposed of.
(iv) One should be monogamous in a sexual relationship.
(v) Dentists should sterilise their instruments.
(vi) Don’t get tattoos or ear and nose piercings from someone who isn’t qualified.
(vii) Avoid the use of common blades in a barber’s shop.
(viii) Many individuals are unaware of AIDS, and it has been argued that “ignorance is bliss.”

Difference Between AIDS and HIV

AIDS	HIV
Acquired Immunodeficiency Syndrome (AIDS)	Human Immunodeficiency Virus(HIV)
The last stage of the spectrum of conditions, initially caused by (HIV)	This virus invades the immune system.
Complications and secondary infections are fatal to the host	Incapable of killing a host by itself.
AIDS is a condition is caused only after an individual is infected by HIV	HIV is a virus that can spread from person to person like all other viruses.
AIDS can be diagnosed by ELISA test and Western Blotting test.	ELISA is used to detect HIV infection.

Summary

The human immunodeficiency virus (HIV) causes AIDS, also known as acquired immunodeficiency syndrome. AIDS was first discovered in homosexuals in the United States in 1981. HIV (human immunodeficiency virus) is a virus that targets the body’s immune system. The virus is disseminated via CD4 cells, commonly known as T-cells, which are a sort of bodily fluid. These unique cells aid the immune system in its fight against illness.

HIV lowers the amount of CD4 cells (T-cells) in the body if left untreated. HIV can damage so many of these cells over time that the body is unable to fight infections and disease. Symptoms of acquired immunodeficiency syndrome are recurring fever, persistent and extreme fatigue, chronic diarrhoea, and neurological disorders such as depression and memory loss. ELISA and Western Blotting tests can both be used to diagnose AIDS. The medications used in the treatment are zidovudine (azidothymidine) and didanosine (dideoxyinosine, DDI).

Frequently Asked Questions (FAQs) from AIDS and HIV

Q.1. How is AIDS caused?
Ans: The human immunodeficiency virus causes HIV infection. HIV is contracted through contact with HIV-infected blood, sperm, or vaginal secretions. The majority of people contract HIV by having unprotected intercourse with an HIV-positive person. Sharing drug needles with someone who is HIV-positive is another typical way to obtain it.

Q.2. Can AIDS symptoms differ by gender?
Ans: Yes. Repeat vaginal yeast infections, pelvic inflammatory disease, irregular menstrual cycles, increased risks of cervical cancer and osteoporosis, and earlier menopause are all possible side effects for HIV-positive women. Women may experience more severe HIV medication side effects, as well as pharmacological interactions between birth control and HIV medicine.

Q.3. Can patients recover from AIDS?
Ans: Although there is no cure for acquired immunodeficiency syndrome (AIDS), medications have been highly effective in fighting HIV and its complications

Q.4. Can a patient receive a false-positive Acquired Immunodeficiency Syndrome test result?
Ans: Yes, it’s a false positive. AIDS test results do happen, but they are extremely uncommon. False positives can occur if the test is handled or labelled incorrectly, specimens are jumbled up, results are misread, or the test is affected by autoimmune illnesses or other medical problems.

Q.5. How does an individual contract Acquired Immunodeficiency Syndrome?
Ans: AIDS is usually spread through sexual contact, sharing of drug needles, or from mother to baby during pregnancy, childbirth, or nursing.

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