HIV and AIDS NEET MCQ - NEET Practice Questions with Answers

• The word AIDS stands for Acquired Immunodeficiency Syndrome.
• This means deficiency of the immune system, acquired during the lifetime of an individual indicating that it is not a congenital disease. 
• ‘Syndrome’ means a group of symptoms. 
• AIDS was first reported in 1981 and in the last twenty-five years or so, it has spread all over the world killing more than 25 million persons.
• It is a disorder of the cell-mediated immune system of the body. 
• There is a reduction in the number of helper T cells which stimulate antibody production by В-cells.

Pathogen (Causative Agent): 

• HIV (Human immunodeficiency virus) is a retrovirus that attacks helper T-cells. 
• Its genome consists of a single-stranded RNA filament segmented into two identical filaments and associated with a reverse transcriptase enzyme. 
• The envelope consists of a lipid bilayer derived from the host cell membranes and projecting knob like glycoprotein spikes. 
• It contains two protein coats.

Mode of Action of HIV: 

• After getting into the body of the person, the virus enters into macrophages where the RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase. 
• This viral DNA gets incorporated into the host cell’s DNA and directs the infected cells to produce virus particles.
• The macrophages continue to produce viruses and in this way acts like an HIV factory. 
• Simultaneously, HIV enters into helper T-lymphocytes replicates and produces progeny viruses. 
• The progeny viruses released in the blood attack other helper T-lymphocytes. 
• This is repeated leading to a progressive decrease in the number of helper T-lymphocytes in the body of the infected person. 
• During this period, the person suffers from bouts of fever, diarrhea and weight loss. Due to a decrease in the number of helper T-lymphocytes, the person starts suffering from infections that could have been otherwise overcome such as those due to bacteria especially Mycobacterium, viruses, fungi and even parasites like Toxoplasma. 
• The patient becomes so immuno-deficient that he/she is unable to protect himself/herself against these infections. 

Transmission of HIV:

• Transmission of HIV-infection generally occurs by:
  • Sexual contact with an infected person, 
  • By transfusion of contaminated blood and blood products, 
  • By sharing infected needles as in the case of intravenous drug abusers
  • From infected mother to her child through the placenta. 
• So, people who are at high risk of getting this infection includes - 
  • individuals who have multiple sexual partners, 
  • drug addicts who take drugs intravenously, 
  • individuals who require repeated blood transfusions 
  • children born to an HIV infected mother

Diagnosis & Treatment:

• A widely used diagnostic test for AIDS is enzyme-linked immunosorbent assay (ELISA).
• Treatment of AIDS with antiretroviral drugs is only partially effective. 
• They can only prolong the life of the patient but cannot prevent death, which is inevitable