11.4 Health Issues Related to Immunity
Learn how HIV attacks the immune system, how AIDS develops, how HIV is transmitted and prevented, and other immune-related health conditions.
Learning Objectives
- Define Acquired Immunodeficiency Syndrome (AIDS) and identify its causative agent, the human immunodeficiency virus (HIV).
- Describe how HIV attacks and destroys lymphocytes, leading to the collapse of the immune system.
- Outline the symptoms and timeline of HIV progression into AIDS.
- Identify the routes of HIV transmission and explain how transmission can be prevented.
- State other conditions related to the immune system, such as Systemic Lupus Erythematosus (SLE) and allergies.
The Infection Cycle and Transmission Pathways of HIV
HIV progressively destroys lymphocytes, leading to AIDS. The virus spreads only through specific body fluids.
HIV attacks lymphocytes
HIV infects, multiplies in, and destroys lymphocytes. Over 8 to 10 years, the immune system becomes progressively weaker.
Transmission routes
HIV spreads through blood, semen, vaginal fluids, and from mother to child across the placenta, during birth, or through breast milk.
Short Explanation
What is AIDS?
AIDS is caused by the human immunodeficiency virus (HIV). HIV infects, multiplies in, and destroys lymphocytes, progressively paralysing the immune system.
Early stage
For the first few years, an infected person shows no visible symptoms even though HIV is actively attacking lymphocytes.
Later stage
After 8 to 10 years, symptoms such as chronic diarrhoea and fungal infections appear. The immune system becomes severely weakened.
Why drug resistance?
HIV mutates rapidly and changes its cell structure as it replicates and spreads, giving the virus high resistance to drug therapy.
Medical specialist
Immunologists are medical specialists who focus on allergy diseases and disorders involving the immune system.
Try to Answer First
Answer in your mind, then press “Check Answer”.
What is the difference between HIV and AIDS?
Why may a person infected with HIV show no symptoms for several years?
State two ways HIV can be transmitted through non-sexual means.
Common Mistakes
- Assuming that HIV immediately causes AIDS upon entering the body; in reality, AIDS only develops after years of progressive lymphocyte destruction.
- Believing that an AIDS patient dies directly from HIV, rather than from opportunistic infections such as severe fungal infections or pneumonia that exploit the paralysed immune system.
- Assuming that all babies born to HIV-positive mothers will inevitably contract HIV, overlooking that proper medical treatments during pregnancy and birth can prevent transmission.
Concept Misunderstandings
HIV can be contracted by sharing food, hugging, or touching an infected individual.
HIV only spreads through the direct transfer of specific body fluids, including blood, semen, and maternal fluids across the placenta or via breast milk.
A person infected with HIV will develop drug resistance because their immune cells fight back against medications.
High resistance to drug therapy occurs because the virus itself frequently mutates and alters its structure as it replicates.
Summary
- HIV (Human Immunodeficiency Virus) attacks and progressively destroys lymphocytes.
- AIDS (Acquired Immunodeficiency Syndrome) is the final stage of HIV infection, marked by a paralysed immune system.
- Symptoms such as chronic diarrhoea and fungal infections typically appear 8 to 10 years after infection.
- Transmission occurs via blood (transfusions, shared needles), semen (unprotected sex), and from mother to child (placenta, birth, breastfeeding).
- Mother-to-child transmission can be avoided through appropriate medical care during pregnancy and delivery.
- Other immune-related health conditions include Systemic Lupus Erythematosus (SLE) and allergies.
Short Activity
Objective: check your understanding of HIV, AIDS, transmission and related immune conditions.
A. Objective Quiz
Which type of cells does the human immunodeficiency virus (HIV) specifically target, infect, and destroy?
After being infected with HIV, how long does it generally take for prominent symptoms such as chronic diarrhoea and fungal infections to become visible?
B. Fill in the Blanks
HIV transmission from an infected mother to her newborn baby can be avoided with proper treatment during pregnancy and birth.
HIV develops high resistance to drug therapy because it is able to and change its cell structure when it spreads.
C. Matching / Drag and Drop
Match each immunological term or health issue to its correct textbook description. On a phone, tap a choice first, then tap the matching box. Tap the Answer Choices area to return a selected item.
C. Match the Term to Its Description
Write the correct term next to each description.
| Description | Term |
|---|---|
| 1. Virus that attacks and progressively destroys lymphocytes | |
| 2. A condition resulting from an immune system paralysed by progressive viral attack | |
| 3. Medical specialist in allergy diseases and immune system conditions | |
| 4. Tool that can transmit HIV when shared during drug injections or tattooing |
Answer choices: HIV • AIDS • Immunologist • Contaminated needle
