Which body fluid is most likely to transmit HIV through a needle-stick injury?

AIIMS CRE 2025

Applied Microbiology & Infection control

Easy

Appeared in: AIIMS CRE 2025

Explanation

Blood contains the highest concentration of the Human Immunodeficiency Virus (HIV) among the options provided, making it the most infectious fluid.
A needle-stick injury is a percutaneous exposure, which provides a direct route for blood-borne pathogens to enter the bloodstream.
Studies show the risk of HIV transmission after a needle-stick injury with HIV-contaminated blood is approximately 0.23% to 0.3%.
Other fluids like semen, vaginal secretions, and breast milk also carry HIV, but blood is the most common vehicle in occupational needle-stick injuries.

Option A: Saliva has a very low viral load and contains enzymes and antiviral factors (like secretory leukocyte protease inhibitor) that inhibit HIV. It is not considered a risk for transmission unless visibly contaminated with blood.
Option B: Sweat does not contain HIV. There is no documented case of HIV transmission through sweat.
Option D: While HIV can be isolated from tears in trace amounts, the concentration is far too low to be a viable route of transmission.

Visual 1: Infographic: A chart categorizing body fluids into 'High Risk' (Blood, Semen, Vaginal Fluid, Breast Milk) and 'No/Low Risk' (Saliva, Sweat, Tears, Urine, Feces) for HIV transmission.
Visual 2: Flowchart: Steps to take after a needle-stick injury, from immediate first aid to reporting and follow-up (PEP).

Clinical Relevance

Nursing practice connection: Knowing Routes of HIV transmission and occupational health risks helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
This concept is the foundation of Standard Precautions, where all body fluids are treated as potentially infectious. This is a critical patient and healthcare worker safety principle.
Nurses must be proficient in the immediate response to a needle-stick injury, including wound care, prompt reporting, and understanding the protocol for Post-Exposure Prophylaxis (PEP) to protect their own health.
What if the patient's HIV status is unknown? The protocol remains the same. The incident must be reported immediately. The source patient will be asked for consent to be tested, and a decision on starting PEP will be made based on a risk assessment of the exposure.

How to Approach the Question

First, identify the key elements of the question: the pathogen (HIV), the route of transmission (needle-stick injury), and the question being asked ('most likely' fluid).
A needle-stick is a percutaneous injury, meaning it breaks the skin and allows direct entry into the body.
Recall the primary modes of HIV transmission. HIV is a blood-borne virus.
Evaluate the options based on their potential to carry a significant viral load. Compare the viral concentration in blood, saliva, sweat, and tears.
Conclude that blood has the highest concentration of HIV and therefore poses the greatest risk for transmission via a needle-stick.
Eliminate the other options as they have negligible to non-existent viral loads and are not considered infectious routes.

Concept Tested & Keywords

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