Why HIV is fragile outside the body
HIV is a virus that can only make copies of itself inside human cells. Once it leaves the body, it can’t multiply, and CDC states that it doesn’t survive long outside the human body, for example on surfaces.
Survival on its own isn’t enough to cause an infection, either. For HIV to infect someone, blood or another fluid that carries it has to reach a mucous membrane (the lining of the eyes, mouth, vagina, rectum or penis), damaged tissue, or be injected into the bloodstream. Touching something with your hands doesn’t do that. Unbroken skin keeps HIV out.
Surfaces and everyday objects
Door handles, toilet seats, towels, bedding, phones, cups, cutlery, gym equipment and money are not a way to get HIV. Even if someone with HIV had touched them, there would be no route from the object into your bloodstream.
This is why HIV isn’t spread by sharing a home, a bathroom or a kitchen with someone who has it. More examples are on the no-risk contact page.
Dried blood
Dried blood on a surface, on clothes or on your skin is not a way to get HIV. HIV doesn’t survive long once it’s outside the body, and touching dried blood with intact skin gives it no way in. Wash it off with soap and water and that’s the end of it.
Blood inside a syringe: the exception
A used syringe is different, because a small amount of blood can stay inside the barrel and needle. In a laboratory study that recreated syringe sharing, researchers recovered live, growing HIV from syringes kept at room temperature for more than four weeks (Abdala 1999). How often the virus survived depended on how much blood was left inside and how much virus was in that blood.
That’s why sharing needles, syringes and other injection equipment carries a real risk, even when the equipment was used days or weeks ago. With someone who has HIV and isn’t on treatment, CDC estimates the risk per shared injection at 0.63% (about 1 in 160). Using new, sterile equipment every time removes it. See sharing needles.
Needles found in public
The same study is a reason to take a needlestick from a discarded needle seriously, though the overall risk is usually low. The person who used it would need to have had HIV, and the injury would need to push their blood into you. The calculator can only give a rough guide here: for a needlestick from someone of unknown status in the United States, it estimates 0.00092% (about 1 in 110,000). Wash the wound with soap and water and get advice the same day. Full steps are on the needlestick page.
Blood in your eyes or a fresh cut
Fresh blood from someone with HIV reaching your eyes, mouth or an open wound carries a small risk, estimated at 0.09% (about 1 in 1,100). Rinse it off straight away. The blood exposures page explains when to ask about PEP.
What isn’t known precisely
You’ll see exact survival times quoted online for HIV in different conditions. Lab results depend on the amount of virus, temperature and how the sample was kept, and they don’t translate neatly into real-life risk. What matters in practice is simpler: surfaces and dried blood aren’t a route for HIV, and fresh blood inside a used syringe can be.
What to do now
- Touched a surface, dried blood or someone else’s belongings? There’s nothing you need to do. You don’t need PEP or a test because of it.
- Stuck by a used needle, shared injection equipment, or had fresh blood in your eyes, mouth or an open wound in the last 72 hours? Ask about PEP (post-exposure prophylaxis) today. It works best within 24 hours and isn’t recommended after 72. How to get PEP
- Still worried? A test after the window period gives a definite answer. See the HIV testing guide.