Viral Diseases and Immunity

HIV multiplies in macrophages and then new viruses targets T - helper cells which makes the infected person immuno - deficient . So the correct option is "T- helper cells"

HIV is a human immunodeficiency virus. When a person is infected by the HIV, it causes HIV infection. It affects the immune system of the body. It infects cells of the human immune system, such as helper T (T$ _H$) cells (CD$ _{4+}$ T cells), macrophages and dendritic cells. Due to this, it is difficult for the body to fight off other infections. 

AIDS virus destroys the immune system by attacking white blood cells called CD4 cells. HIV gets inside the CD4 cells and make copies of itself and then kills the CD4  cell. The new HIV copies find other CD4 cells to attack them. Thus, it destroys the immune cells, therefore reduces immunity. 

HIV (Human Immunodeficiency Virus) has a viral envelope, matrix proteins and core. The viral core consists of two single strands of RNA for its genome. The RNA genome consists of ribonucleotides (ribose + nitrogenous bases + phosphate) wherein thymine is replaced by uracil. The quick mutation rate of RNA genome makes it difficult to have a vaccine against it. The viral coat has trimeric glycoprotein gp120 which contacts CD4 terminal domain of the T4 cell. This contact leads to activation of gp120 followed by contact with chemokines receptor CCR5, a multipass membrane protein.  The result is activated gp41 which in turn cleaves gp120.  The terminal domain of gp41 interacts with the target cell and fuses with the T cell membrane to facilitate entry of virus with capsid into the cell.  RNA retroviruses have reverse transcriptase enzyme that synthesizes a DNA copy (cDNA) of viral RNA. Thus, the correct answer is option D.

HIV attacks and kills immune systems cells known as Helper T cells. Without Helper T cells many other immune system cells cannot work properly, including B cells that make antibodies 

HIV is a virus that targets and alters the immune system, increasing the risk and impact of other infections and diseases. It damages the immune system and infects macrophages, T- cells etc.

Corynebacterium diphtheriae is a virus causing diphtheria. 
Rubella virus causes measles. 
Varicella virus causes chickenpox.
Human immunodeficiency virus infection is a disease of human immune system, which causes acquired immune deficiency syndrome. It is transmitted through sexual contact, breastfeeding and blood transfusion.
Thus, the correct answer is option B.

HIV (Human Immunodeficiency Virus) is the causative agent of AIDS. HIV is spread from an infected person to another person through direct contact with some of the body’s fluids like mother milk, blood, lymph and semen through sexual intercourse or by sharing the drug equipment like needles or from mother to child during childbirth or breastfeeding or via blood transfusion.
Thus, the correct answer is option A.

• AIDS(acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
  
• The first AIDS cases were reported in the United States in June 1981.
  
• Hence AIDS was first reported in U.S.A in 1981.
  
• So, the correct answer is '1981'.
  

• AIDS(acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
• As HIV is liable to be transmitted to people, organisms, etc. through the environment. Hence it is an infectious disease.
• AIDS does not spread from person to person through direct contact (touching a person who has the infection), indirect contact (touching a contaminated object), or droplet contact (inhaling droplets made when a person who has the infection coughs, sneezes, or talks). Hence it is a non-contagious
• Hence AIDS Is infectious and non -contagious disease..
• So, the correct answer is 'Both B and C'. 

• AIDS(acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
• The first AIDS cases were reported in the United States in June 1981.
• Approximate number of AIDs patients worldwide is  36.9 million. Of these, 1.8 million were children (<15 years old). An estimated 1.8 million individuals worldwide became newly infected with HIV in 2017 – about 5,000 new infections per day
• So, the correct answer is '36.9 million'.

• AIDS (acquired immunodeficiency syndrome) is caused by the HIV virus. It breaks down the body immune system, leaving the patient vulnerable to a host of life-threatening opportunistic infections.
• AIDS does not spread from person to person through direct contact (touching a person who has the infection or kissing), indirect contact (touching a contaminated object or food), or droplet contact (inhaling droplets made when a person who has the infection coughs, sneezes, or talks). 
  
• AIDS virus(HIV) enters the human body through blood when wrongly transfused from an AIDS infected patient or usage of needles and syringes of the AIDS infected person.
• So, the correct answer is 'Blood'.

Human immunodeficiency virus infection or acquired immune deficiency syndrome (HIV/AIDS) is a serious immune disorder caused by infection with the human immunodeficiency virus (HIV). HIV is different in structure from other retroviruses. It is composed of two copies of positive-sense single-stranded RNA. HIV replicates in T4 cells. AIDS is a sexually transmitted infection and transmitted through sexual contact and sharing infected needles. It is not spread by mere touch or physical contact. There is currently no cure or effective HIV vaccine. Treatment consists of highly active antiretroviral therapy which slows progression of the disease. HIV usually causes flu-like symptoms about two to four weeks after transmission. This short period of time is called acute infection.