To protect yourself from HIV, remember to look both ways. You can be hit by HIV through sex or through blood. Even very small amounts of blood – such as might be found on reused needles or razors – could infect you if it could get past your skin.
During medical and cosmetic procedures such as injections, tattooing, or haircuts, instruments such as needles, clippers, or razors may jab or cut someone, and thereby pick up small amounts of their blood. If someone is infected with HIV, a drop of their blood as small as the period at the end of this sentence may have several HIV particles. Any one of these particles could infect you if it could past your skin.
HIV in small amounts of blood can live for some time outside the body. Even after blood dries on a razor, for example, some HIV can live for hours.1 If blood stays wet – such as in a needle or syringe – HIV can live for weeks.2
Wiping or rinsing bloody instruments with alcohol or bleach does not reliably kill all HIV. Even soaking instruments in these solutions is often not reliable. Dettol does not kill HIV or other viruses, even with long soaking.
For all instruments that pierce the skin, heat is the best way to kill whatever HIV might be on the instruments. Even very brief boiling kills HIV. Longer boiling is needed to kill other pathogens. For instruments that cannot be boiled, such as plastic tubes, dentists and doctors can kill HIV by soaking them for 30 minutes in special chemicals, such as glutaraldehyde. (For more information, see references 3-4.)
When a doctor reuses syringes without boiling, even if he changes needles, patients are not safe. When someone gets an injection, his or her muscle might push some blood back into the needle at the end of the injection, or the needle might suck out some blood when the doctor pulls it out of the skin. Then, when the doctor removes the needle, this causes some suction when the nozzle of the needle pulls away from the syringe. This can suck whatever is in the needle onto the tip of the syringe. Thus, even with a new needle, a syringe that is reused without boiling can pass HIV from one patient to others.5
To protect yourself from HIV infections: Look both ways.
When you know someone is HIV-positive: Remember they may have been infected through blood during injections, dental care, etc. Just knowing they are HIV-positive does not tell you anything about their sexual behavior.
1. van Bueren J et al. Survival of human immunodeficiency virus in suspension and dried onto surfaces. J Clin Microbiology 1994; 32: 571-574. Available at: http://jcm.asm.org/cgi/reprint/32/2/571?view=long&pmid=8150980.
2. Abdala N et al. Survival of HIV-1 in syringes, J Acquir Immune Defic Syndr 1999; 20: 73-80.
3. WHO. Guidelines on sterilization and disinfection methods effective against human immunodeficiency virus, 2nd edition. WHO AIDS Series 2. Geneva: WHO, 1989.Available at: http://whqlibdoc.who.int/aids/
4. Sopwith W et al. Preventing infection from reusable medical equipment: a systematic review. BMC Infect Dis 2002; 2: 4. Available at: http://www.biomedcentral.com/1471-2334/2/4.
5. Evans RJ, Spooner ETC. A possible mode of transfer of infection by syringes used for mass inoculation. Br Med J 1950; ii: 185-188.
