Which of the following is the most prevalent cause of immunodeficiency worldwide?

• A. Malnutrition
• B. Human immunodeficiency virus (HIV) infection
• C. Congenital immunodeficiency disorders
• D. Use of immunosuppressive drugs

Answer: (B)

Verified step by step guidance

1. Understand the term 'immunodeficiency,' which refers to a state where the immune system's ability to fight infectious disease and cancer is compromised or entirely absent.
2. Review the common causes of immunodeficiency, which include malnutrition, infections like HIV, congenital (genetic) immunodeficiency disorders, and the use of immunosuppressive drugs.
3. Consider the global prevalence and impact of each cause. Malnutrition is widespread and can impair immune function, but it is often a contributing factor rather than a direct cause of immunodeficiency.
4. Recognize that Human Immunodeficiency Virus (HIV) infection directly targets and destroys key immune cells (CD4+ T cells), leading to acquired immunodeficiency syndrome (AIDS), which is a major global health issue.
5. Conclude that among the options, HIV infection is the most prevalent direct cause of immunodeficiency worldwide due to its widespread transmission and profound impact on the immune system.