Which statement is true regarding HIV-1 and HIV-2?

Appeared in: AIIMS CRE 2025

Explanation

HIV-1 is the most common cause of HIV disease throughout the world and is responsible for the global AIDS pandemic.
HIV-2, while also causing AIDS, is less common and was originally confined to West Africa.
Epidemiological data clearly shows that HIV-1 infections vastly outnumber HIV-2 infections on a global scale.

Option A: This statement is false. HIV-1 is significantly more virulent and pathogenic than HIV-2.
Option C: This is incorrect. HIV-2 infection is known for a longer asymptomatic period and slower progression to AIDS compared to HIV-1.
Option D: This is false. There is a large disparity in the prevalence of the two viruses. HIV-1 is responsible for the overwhelming majority of cases worldwide.

Visual 1: World Map - A color-coded map illustrating the global distribution and prevalence of HIV-1 (widespread, high prevalence in many regions) versus HIV-2 (concentrated in West Africa with sporadic cases elsewhere). This would visually reinforce the correct answer.
Visual 2: Infographic - A comparative chart showing the key differences between HIV-1 and HIV-2, including icons for prevalence, virulence, transmission rate, and disease progression timeline.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Differences between HIV-1 and HIV-2 as background academic context rather than a clinical decision trigger.
Understanding the difference is crucial for diagnosis. Standard HIV-1 screening tests may give indeterminate results for HIV-2, so specific combination tests are needed if HIV-2 is suspected based on geographic exposure.
Treatment strategies can differ. While many antiretroviral drugs are effective against both, HIV-2 has intrinsic resistance to certain classes of drugs (e.g., non-nucleoside reverse transcriptase inhibitors).
Patient counseling must be tailored. A patient with HIV-2 might have a slower disease course, but still requires monitoring and eventual treatment. Counseling on the lower, but still present, risk of transmission is also important.

How to Approach the Question

First, identify the core concept of the question, which is comparing the characteristics of HIV-1 and HIV-2.
The question asks for a 'true' statement. This means you must evaluate each option for its factual accuracy.
Recall or look up the key differences: prevalence (global distribution), virulence (severity/harmfulness), and rate of disease progression.
Evaluate Option A: Is HIV-2 more virulent? No, HIV-1 is more virulent.
Evaluate Option B: Is HIV-1 more common globally? Yes, it's the cause of the pandemic.
Evaluate Option C: Does HIV-2 progress faster? No, it progresses slower.

Concept Tested & Keywords

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Practise the full AIIMS CRE 2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.