Question

A patient had tested positive to ELISA Test.

I) Identify the disease and the pathogen.

ii) Give reasons for the reduced/ weak immunity of the patient.

(iii) Trace the path, spread and effects of this pathogen in the human body.​

Answer 1

Answer:

i)

Disease: Acquired immunodeficiency Syndrome(AIDS)

Pathogen: Human immunodeficiency virus (HIV).

ii) Reasons:

Due to decrease in the number of helper T lymphocytes, the person starts suffering from infections due to bacteria such as Mycobacterium, viruses, fungi and parasites like Toxoplasma.

iii)

Path:

• After getting into the body of the person, the virus enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase.

• This viral DNA gets incorporated into host cell’s DNA and directs the infected cells to produce virus particles.

Spread:

• HIV enters into helper T-lymphocytes (TH), replicates and produce 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.

Effects:

• At this period, the person suffers from fever, diarrhea and weight loss.