Sexually Transmitted Diseases (STD) or Sexually Transmitted Infections (STI) - Acquired Immuno Deficiency Syndrome (AIDS)

AIDS stands for Acquired Immuno Deficiency Syndrome. It is an immune system deficiency acquired during an individual's lifetime, so it is not a congenital disease. The term "syndrome" refers to a group of symptoms. It is a usually fatal illness caused by Human Immunodeficiency Virus (HIV).

Structure of HIV

Causal organism:

• HIV is a retrovirus.
• It has an envelope enclosing the RNA genome.
• It contains single-stranded RNA and the enzyme reverse transcriptase.
• The virus is spherical and measures about 100 to 140 nm in diameter.
• It shows two centrally located ssRNA molecules along with reverse transcriptase enzymes.
• It is covered by protein layers, including matrix protein p17 and capsid protein p24, and an outer lipid layer with glycoproteins GP120 and GP41.

Site of action:

• HIV resides chiefly within T-lymphocytes and mainly destroys T4 / CD4 helper T-cells.
• These cells play a central role in maintaining the body’s response to infection.
• The virus also enters macrophages, where it replicates and continues producing more virus.

A retrovirus like HIV:

• Enters a normal animal cell.
• Uses reverse transcriptase to change its RNA into DNA.
• Its DNA integrates with the host cell's DNA in the nucleus.
• The cell then makes new viral RNA and proteins, forming many new viruses.
• These new viruses leave the original cell and infect other cells, while the original cell can remain alive.

Replication of retrovirus

• After entering the body, HIV enters macrophages.
• The RNA genome of the virus forms viral DNA with the help of reverse transcriptase.
• This viral DNA is incorporated into the host cell's DNA and directs infected cells to produce viral particles.
• Macrophages continue to produce the virus and act like an HIV factory.
• Simultaneously, HIV enters helper T-lymphocytes, replicates, and produces progeny viruses.
• The released viruses attack more helper T-lymphocytes, causing their number to decrease progressively.
• Due to this decline, the body becomes immunodeficient and unable to cope even with infections that are otherwise manageable.

Mechanism of HIV action

• There is a time lag between infection and the appearance of symptoms.
• The incubation period ranges from months to years, described as 6 months to 10 years in one account and 6 months to 5 years, possibly longer in another.
• During the asymptomatic stage, no signs of disease may be seen.
• Once the disease is fully developed, there may be a rapid decline in health.

• Early symptoms may be vague and ill-defined.
• These include weight loss, fever, diarrhoea, oral thrush, fatigue, enlarged lymph glands, night sweats, and shortness of breath.
• Some individuals develop AIDS-related complex (ARC).
• In severe conditions, the patient may develop pneumonia, tuberculosis, Kaposi’s sarcoma, and lymphoma.
• The end stage is characterised by life-threatening opportunistic infections and unusual malignancies.

• HIV infection is transmitted by sexual contact with an infected person.
• It is transmitted by transfusion of contaminated blood and blood products.
• It is transmitted by sharing infected needles, including hypodermic needles used by drug addicts.
• It is transmitted from an infected mother to her child through the placenta, before birth, during birth, shortly after birth, or through breast milk.
• Other rare methods include accidental needle injury, artificial insemination with infected semen, and transplantation with infected organs.
• It spreads through body fluids.

• Individuals with multiple sexual partners are at high risk.
• Intravenous drug users who share needles are at high risk.
• Individuals requiring repeated blood transfusions are at high risk.
• Children born to an infected mother are at high risk.

• A widely used diagnostic test is ELISA (Enzyme-Linked Immunosorbent Assay).
• One account states that a first test is used to detect HIV antibodies, and a second confirmatory test is done to rule out false positives.
• The confirmatory test mentioned is Western Blot.
• Western Blot is described as a highly specific test based on detecting antibodies to the viral core protein and envelope glycoprotein.

• AIDS has no cure or no effective treatment according to the material.
• Anti-retroviral drugs can help reduce viral load and prolong life.
• The effect of anti-retroviral drugs is described as partial.
• Drugs mentioned include AZT (azidothymidine), TDF (tenofovir), EFV (efavirenz), and Lamivudine (3TC).
• AZT is stated to prevent reverse transcription.
• One account also mentions N-butyl deoxynojirimycin/N-butyl deoxynojorimycin as a drug that shows promise.
• Effects described with AZT include increased helper T-cells, improved immunological capacity, weight gain, and improved general well-being.

• Prevention is stated to be the best option because AIDS has no cure.
• People, especially high-risk groups, should be educated about HIV transmission.
• Disposable needles and syringes should be used and properly discarded.
• Safe sexual behaviour is advised.
• Blood should be screened before transfusion.
• People at risk should not donate blood.
• Toothbrushes, razors, and other articles that may be contaminated with blood should not be shared.
• Routine screening is mentioned for blood donors, organ donors, semen donors, growth hormone donors, patients on haemodialysis, and females in high-risk groups who are pregnant or planning pregnancy.
• Additional steps listed include free distribution of condoms, controlling drug abuse, and promoting regular check-ups.

• It is stated that infected persons need help and sympathy instead of being shunned by society.
• It is also stated that the disease must be tackled by society and the medical fraternity acting together.
• 1 December is observed as World AIDS Day.
• Red ribbon is mentioned as a universal symbol of awareness and support for people living with HIV.

• AIDS is a fatal, non-congenital condition caused by HIV, leading to severe immune system deficiency.
• HIV is a spherical retrovirus featuring two single-stranded RNA molecules, the enzyme reverse transcriptase, and a lipid envelope with specific glycoproteins.
• The virus targets and destroys CD4 (T4) helper T-cells and uses macrophages as replication factories, progressively weakening the host's immune response.
• Transmission occurs through contact with infected body fluids, specifically via sexual intercourse, contaminated blood transfusions, shared needles, or from mother to child.
• Individuals at high risk include those with multiple sexual partners, intravenous drug users, recipients of repeated blood transfusions, and children born to infected mothers.
• Diagnosis involves a primary screening test called ELISA, followed by a highly specific confirmatory test known as Western Blot.
• While there is no cure, antiretroviral drugs like AZT can partially reduce viral load and extend patients' lifespans.
• Prevention - including education, safe sexual practices, blood screening, and the use of disposable needles - is critical, supported by social sympathy for those living with HIV.