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Why does sharing unsanitized hypodermic needles increase the risk of HIV transmission?
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sexually transmitted disease
Scanning electron micrograph of the spirochete Treponema pallidum attached to testicular cell membranes.
Sharing unsanitized hypodermic needles increases the risk of HIV transmission because the virus is spread through the direct transfer of infected bodily fluids, specifically blood.12
When a needle or syringe is used by an individual living with HIV, it can become contaminated with microscopic amounts of their blood. If that same needle is then used by another person without being properly sanitized, the virus can be introduced directly into the second person's bloodstream. Because HIV requires the direct exchange of bodily fluids to survive and infect a new host—as it is fragile and cannot survive long outside the body—sharing equipment that bypasses the body's natural barriers poses a significant risk of infection.12