Question

Read the following passage and answer the questions that follow.
In 1981, the health workers of United States of America had become aware of the increased frequency of Kaposi’s sarcoma, cancer of the skin and blood vessels and another disease pneumocystis pneumonia, a respiratory infection caused by a protozoan. Both these diseases were very rare in the general population, but occurred frequently in more severely “immunosuppressed” individuals. This led to the recognition of the immune system disorder that was named Acquired Immune Deficiency Syndrome (AIDS). In 1983, virologists working in the USA and France had identified a causative agent for ’AIDS’, now known as Human Immunodeficiency Virus (HIV). “HIV” follows a set path to attack the human body to cause the disease.
(a) Name the group of cells the HIV attacks after gaining entry into the human body and write the various events that occur within this cell.
(b) Write the expanded form of the diagnostic test used for detecting AIDS. Write the possible treatment available for the disease at present.
(c) Mention any two steps suggested by WHO for preventing the spread of this disease.
(c) “A patient suffering from AIDS does not die of this disease but from some other infection.” Justify the statement.

Hint:

(a) HIV attacks CD4+ T-cells, weakening the immune system and making the body vulnerable to opportunistic infections.
(b) ART does not cure HIV but helps manage the infection and prolong the patient’s life by suppressing the virus.
(c) Preventive measures like safe sexual practices and proper blood screening significantly reduce the risk of HIV transmission.
(c)

Answer 1

(a) - HIV primarily targets CD4+ T-helper cells.
- After entering the cell:
1. The viral RNA is converted into DNA by reverse transcriptase.
2. The viral DNA integrates into the host cell’s genome using the enzyme integrase.
3. The host cell machinery is hijacked to produce viral particles, leading to the destruction of CD4+ cells.
(b) - The expanded form of the diagnostic test is Enzyme-Linked Immunosorbent Assay (ELISA).
- Possible treatments:
- The current treatment involves Antiretroviral Therapy (ART). This therapy uses a combination of antiretroviral drugs to suppress viral replication, improve immune function, and prevent progression to AIDS.
(c) Two steps suggested by WHO for preventing the spread of HIV are: 1. Safe sexual practices: Use of condoms to prevent transmission through sexual contact. 2. Screening of blood: Ensuring all blood and blood products are screened for HIV before transfusion.
(c) - AIDS weakens the immune system by destroying CD4+ T-cells, making the body unable to fight opportunistic infections.
- Common infections include:
-- Pneumonia (caused by Pneumocystis jirovecii).
-- Tuberculosis (caused by Mycobacterium tuberculosis).
These infections, rather than HIV itself, lead to the death of the patient.