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Do not fill this in! == Transmission == {{Risk of acquiring HIV}} HIV is spread by three main routes: [[human sexual activity|sexual contact]], significant exposure to infected body fluids or tissues, and from mother to child during pregnancy, delivery, or breastfeeding (known as [[vertical transmission]]).<ref name=TransmissionM2007/> There is no risk of acquiring HIV if exposed to [[feces]], nasal secretions, saliva, [[sputum]], sweat, tears, urine, or vomit unless these are contaminated with blood.<ref name=AFP2007k>{{cite journal |vauthors=Kripke C |title=Antiretroviral prophylaxis for occupational exposure to HIV |journal=American Family Physician |volume=76 |issue=3 |pages=375β76 |date=August 2007 |pmid=17708137}}</ref> It is also possible to be [[Coinfection|co-infected]] by more than one strain of HIVβa condition known as [[HIV superinfection]].<ref>{{cite journal |vauthors=van der Kuyl AC, Cornelissen M |title=Identifying HIV-1 dual infections |journal=Retrovirology |volume=4 |page=67 |date=September 2007 |pmid=17892568 |pmc=2045676 |doi=10.1186/1742-4690-4-67 |doi-access=free }}</ref> === Sexual === <!--Overview --> The most frequent mode of transmission of HIV is through sexual contact with an infected person.<ref name=TransmissionM2007/> However, an HIV-positive person who has an undetectable viral load as a result of long-term treatment has effectively no risk of transmitting HIV sexually.<ref name="CDCUndetectable" /><ref name="Risk of sexual transmission of huma"/> The existence of functionally noncontagious HIV-positive people on antiretroviral therapy was controversially publicized in the 2008 [[Swiss Statement]], and has since become accepted as medically sound.<ref>{{cite journal |last1=Vernazza |first1=P |last2=Bernard |first2=EJ |title=HIV is not transmitted under fully suppressive therapy: The Swiss Statement β eight years later |journal=Swiss Medical Weekly |date=January 29, 2016 |volume=146 |pages=w14246 |doi=10.4414/smw.2016.14246|pmid=26824882 |doi-access=free }}</ref> Globally, the most common mode of HIV transmission is via [[Heterosexuality|sexual contacts between people of the opposite sex]];<ref name=TransmissionM2007/> however, the pattern of transmission varies among countries. {{As of|2017}}, most HIV transmission in the United States occurred among [[men who had sex with men]] (82% of new HIV diagnoses among males aged 13 and older and 70% of total new diagnoses).<ref>{{cite web |title=HIV and Men |url=https://www.cdc.gov/hiv/group/gender/men/index.html |website=U.S. [[Centers for Disease Control and Prevention]] (CDC) |access-date=November 3, 2019 |archive-url=https://web.archive.org/web/20191201111721/https://www.cdc.gov/hiv/group/gender/men/index.html |archive-date=December 1, 2019 |url-status=live }}</ref><ref>{{cite web |title=HIV and Gay and Bisexual Men |url=https://www.cdc.gov/hiv/group/msm/index.html |website=U.S. [[Centers for Disease Control and Prevention]] (CDC) |access-date=November 3, 2019 |archive-url=https://web.archive.org/web/20191102163544/https://www.cdc.gov/hiv/group/msm/index.html |archive-date=November 2, 2019 |url-status=live }}</ref> In the US, gay and bisexual men aged 13 to 24 accounted for an estimated 92% of new HIV diagnoses among all men in their age group and 27% of new diagnoses among all gay and bisexual men.<ref name=CDC2016Bi>{{cite web |title=HIV Among Gay and Bisexual Men |url=https://www.cdc.gov/hiv/pdf/group/msm/cdc-hiv-msm.pdf |access-date=January 1, 2017 |url-status=live |archive-url=https://web.archive.org/web/20161218225712/https://www.cdc.gov/hiv/pdf/group/msm/cdc-hiv-msm.pdf |archive-date=December 18, 2016 }}</ref> <!--Per act risk --> With regard to [[unprotected sex|unprotected]] heterosexual contacts, estimates of the risk of HIV transmission per sexual act appear to be four to ten times higher in low-income countries than in high-income countries.<ref name=Boily2009/> In low-income countries, the risk of female-to-male transmission is estimated as 0.38% per act, and of male-to-female transmission as 0.30% per act; the equivalent estimates for high-income countries are 0.04% per act for female-to-male transmission, and 0.08% per act for male-to-female transmission.<ref name=Boily2009/> The risk of transmission from anal intercourse is especially high, estimated as 1.4β1.7% per act in both heterosexual and homosexual contacts.<ref name=Boily2009/><ref>{{cite journal |vauthors=Beyrer C, Baral SD, van Griensven F, Goodreau SM, Chariyalertsak S, Wirtz AL, Brookmeyer R |title=Global epidemiology of HIV infection in men who have sex with men |journal=The Lancet |volume=380 |issue=9839 |pages=367β77 |date=July 2012 |pmid=22819660 |doi=10.1016/S0140-6736(12)60821-6 |pmc=3805037}}</ref> While the risk of transmission from [[oral sex]] is relatively low, it is still present.<ref>{{cite journal |vauthors=Yu M, Vajdy M |title=Mucosal HIV transmission and vaccination strategies through oral compared with vaginal and rectal routes |journal=[[Expert Opinion on Biological Therapy]] |volume=10 |issue=8 |pages=1181β95 |date=August 2010 |pmid=20624114 |pmc=2904634 |doi=10.1517/14712598.2010.496776}}</ref> The risk from receiving oral sex has been described as "nearly nil";<ref>{{cite book |last=StΓΌrchler |first=Dieter A. |title=Exposure a guide to sources of infections |year=2006 |publisher=ASM Press |location=Washington, DC |isbn=978-1-55581-376-5 |page=544 |url=https://books.google.com/books?id=MWa5or3Xa9EC&pg=PA544 |access-date=June 27, 2015 |archive-url=https://web.archive.org/web/20151130024240/https://books.google.com/books?id=MWa5or3Xa9EC&pg=PA544 |archive-date=November 30, 2015 |url-status=live }}</ref> however, a few cases have been reported.<ref>{{cite book |veditors=Pattman R, etal |title=Oxford handbook of genitourinary medicine, HIV, and sexual health |year=2010 |publisher=[[Oxford University Press]] |location=Oxford |isbn=978-0-19-957166-6 |page=95 |edition=2nd}}</ref> The per-act risk is estimated at 0β0.04% for receptive oral intercourse.<ref name=Dosekun2010>{{cite journal |vauthors=Dosekun O, Fox J |title=An overview of the relative risks of different sexual behaviours on HIV transmission |journal=[[Current Opinion in HIV and AIDS]] |volume=5 |issue=4 |pages=291β97 |date=July 2010 |pmid=20543603 |doi=10.1097/COH.0b013e32833a88a3|s2cid=25541753 }}</ref> In settings involving [[prostitution]] in low-income countries, risk of female-to-male transmission has been estimated as 2.4% per act, and of male-to-female transmission as 0.05% per act.<ref name=Boily2009>{{cite journal |vauthors=Boily MC, Baggaley RF, Wang L, Masse B, White RG, Hayes RJ, Alary M |title=Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies |journal=The Lancet. Infectious Diseases |volume=9 |issue=2 |pages=118β29 |date=February 2009 |pmid=19179227 |pmc=4467783 |doi=10.1016/S1473-3099(09)70021-0}}</ref> <!--Factors that increase the risk --> Risk of transmission increases in the presence of many [[sexually transmitted infection]]s<ref name=CochraneSTI2012>{{cite journal |vauthors=Ng BE, Butler LM, Horvath T, Rutherford GW |title=Population-based biomedical sexually transmitted infection control interventions for reducing HIV infection |journal=[[The Cochrane Database of Systematic Reviews]] |issue=3 |page=CD001220 |date=March 2011 |pmid=21412869 |doi=10.1002/14651858.CD001220.pub3 |editor1-last=Butler |editor1-first=Lisa M}}</ref> and [[genital ulcer]]s.<ref name=Boily2009/> Genital ulcers appear to increase the risk approximately fivefold.<ref name=Boily2009/> Other sexually transmitted infections, such as [[gonorrhea]], [[Chlamydia infection|chlamydia]], [[trichomoniasis]], and [[bacterial vaginosis]], are associated with somewhat smaller increases in risk of transmission.<ref name=Dosekun2010/> The [[viral load]] of an infected person is an important risk factor in both sexual and mother-to-child transmission.<ref>{{cite journal |vauthors=Anderson J |title=Women and HIV: motherhood and more |journal=Current Opinion in Infectious Diseases |volume=25 |issue=1 |pages=58β65 |date=February 2012 |pmid=22156896 |doi=10.1097/QCO.0b013e32834ef514|s2cid=6198083 }}</ref> During the first 2.5 months of an HIV infection a person's infectiousness is twelve times higher due to the high viral load associated with acute HIV.<ref name=Dosekun2010/> If the person is in the late stages of infection, rates of transmission are approximately eightfold greater.<ref name=Boily2009/> Commercial sex workers (including [[Sexually transmitted infections in the pornography industry|those in pornography]]) have an increased likelihood of contracting HIV.<ref>{{cite book |url=https://books.google.com/books?id=f60h4OyZu_QC&pg=PA1 |title=The Global HIV Epidemics among Sex Workers |last=Kerrigan |first=Deanna |publisher=World Bank Publications |year=2012 |isbn=978-0-8213-9775-6 |pages=1β5 |access-date=June 27, 2015 |archive-url=https://web.archive.org/web/20150919020557/https://books.google.com/books?id=f60h4OyZu_QC&pg=PA1 |archive-date=September 19, 2015 |url-status=live }}</ref><ref>{{cite book |last=Aral |first=Sevgi |title=The New Public Health and STD/HIV Prevention: Personal, Public and Health Systems Approaches |year=2013 |publisher=Springer |isbn=978-1-4614-4526-5 |page=120 |url=https://books.google.com/books?id=eBbQ5QuqL9IC&pg=PA120 |access-date=June 27, 2015 |archive-url=https://web.archive.org/web/20150924071934/https://books.google.com/books?id=eBbQ5QuqL9IC&pg=PA120 |archive-date=September 24, 2015 |url-status=live }}</ref> Rough sex can be a factor associated with an increased risk of transmission.<ref>{{cite journal |vauthors=Klimas N, Koneru AO, Fletcher MA |title=Overview of HIV |journal=Psychosomatic Medicine |volume=70 |issue=5 |pages=523β30 |date=June 2008 |pmid=18541903 |doi=10.1097/PSY.0b013e31817ae69f|s2cid=38476611 }}</ref> [[Sexual assault]] is also believed to carry an increased risk of HIV transmission as condoms are rarely worn, physical trauma to the vagina or rectum is likely, and there may be a greater risk of concurrent sexually transmitted infections.<ref>{{cite journal |vauthors=Draughon JE, Sheridan DJ |title=Nonoccupational postexposure prophylaxis following sexual assault in industrialized low-HIV-prevalence countries: a review |journal=Psychology, Health & Medicine |volume=17 |issue=2 |pages=235β54 |year=2012 |pmid=22372741 |doi=10.1080/13548506.2011.579984|s2cid=205771853 }}</ref> === Body fluids === [[File:AIDS Poster If You're Dabbling in Drugs 1989.jpg|thumb|alt=A black-and-white poster of a young black man with a towel in his left hand with the words "If you are dabbling with drugs you could be dabbling with your life" above him|CDC poster from 1989 highlighting the threat of AIDS associated with drug use]] The second-most frequent mode of HIV transmission is via blood and blood products.<ref name=TransmissionM2007/> Blood-borne transmission can be through needle-sharing during intravenous drug use, needle-stick injury, transfusion of contaminated blood or blood product, or medical injections with unsterilized equipment. <!--IVDU and needle stick -->The risk from sharing a needle during [[drug injection]] is between 0.63% and 2.4% per act, with an average of 0.8%.<ref name=Risk2006>{{cite journal |vauthors=Baggaley RF, Boily MC, White RG, Alary M |title=Risk of HIV-1 transmission for parenteral exposure and blood transfusion: a systematic review and meta-analysis |journal=AIDS |volume=20 |issue=6 |pages=805β12 |date=April 2006 |pmid=16549963 |doi=10.1097/01.aids.0000218543.46963.6d|s2cid=22674060 |doi-access=free }}</ref> The risk of acquiring HIV from a needle stick from an HIV-infected person is estimated as 0.3% (about 1 in 333) per act and the risk following [[mucous membrane]] exposure to infected blood as 0.09% (about 1 in 1000) per act.<ref name=AFP2007k/> This risk may, however, be up to 5% if the introduced blood was from a person with a high viral load and the cut was deep.<ref name=Needle2002>{{cite web |title=Needlestick Prevention Guide |url=https://www.who.int/occupational_health/activities/2needguid.pdf |access-date=November 10, 2019 |pages=5β6 |date=2002 |archive-url=https://web.archive.org/web/20180712204534/http://www.who.int/occupational_health/activities/2needguid.pdf |archive-date=July 12, 2018 |url-status=live }}</ref> In the United States, intravenous drug users made up 12% of all new cases of HIV in 2009,<ref name=TransmissionCDC2012>{{cite web |title=HIV in the United States: An Overview |url=https://www.cdc.gov/hiv/topics/surveillance/resources/factsheets/us_overview.htm |website=Center for Disease Control and Prevention |date=March 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130501102910/http://www.cdc.gov/hiv/topics/surveillance/resources/factsheets/us_overview.htm |archive-date=May 1, 2013 }}</ref> and in some areas more than 80% of people who inject drugs are HIV-positive.<ref name=TransmissionM2007/> <!--Blood transfusion --> HIV is transmitted in about 90% of [[blood transfusion]]s using infected blood.<ref name="Blood Transfusion Risk"/> In developed countries the risk of acquiring HIV from a blood transfusion is extremely low (less than one in half a million) where improved donor selection and [[HIV screening]] is performed;<ref name=TransmissionM2007/> for example, in the UK the risk is reported at one in five million<ref>{{cite web |title=Will I need a blood transfusion? |year=2011 |url=http://hospital.blood.co.uk/library/pdf/2011_Will_I_Need_English_v3.pdf |publisher=National Health Services |access-date=August 29, 2012 |url-status=live |archive-url=https://web.archive.org/web/20121025050828/http://hospital.blood.co.uk/library/pdf/2011_Will_I_Need_English_v3.pdf |archive-date=October 25, 2012 }}</ref> and in the United States it was one in 1.5 million in 2008.<ref>{{cite journal |title=HIV transmission through transfusion β Missouri and Colorado, 2008 |journal=[[Morbidity and Mortality Weekly Report]] |volume=59 |issue=41 |pages=1335β39 |date=October 2010 |pmid=20966896 |author1=Centers for Disease Control Prevention (CDC)}}</ref> In low-income countries, only half of transfusions may be appropriately screened (as of 2008),<ref name=UN2011Seventy>UNAIDS 2011 pg. 60β70</ref> and it is estimated that up to 15% of HIV infections in these areas come from transfusion of infected blood and blood products, representing between 5% and 10% of global infections.<ref name=TransmissionM2007/><ref name=WHO070401>{{cite web |publisher=World Health Organization |year=2001 |url=https://www.who.int/inf-pr-2000/en/pr2000-25.html |title=Blood safety ... for too few |archive-date=January 17, 2005 |archive-url=https://web.archive.org/web/20050117092135/http://www.who.int/inf-pr-2000/en/pr2000-25.html}}</ref> It is possible to acquire HIV from organ and tissue [[Organ transplantation|transplantation]], although this is rare because of [[Diagnosis of HIV/AIDS|screening]].<ref>{{cite journal |vauthors=Simonds RJ |title=HIV transmission by organ and tissue transplantation |journal=[[AIDS (journal)|AIDS]] |volume=7 |pages=S35β38 |date=November 1993 |issue=Suppl 2 |pmid=8161444 |doi=10.1097/00002030-199311002-00008 |s2cid=28488664 |url=https://zenodo.org/record/1234768 |access-date=October 16, 2019 |archive-date=October 6, 2020 |archive-url=https://web.archive.org/web/20201006095732/https://zenodo.org/record/1234768/ |url-status=live }}</ref> <!--Non-sanitary health practices - this is about medical injections in particular --> Unsafe medical injections play a role in [[HIV/AIDS in Africa|HIV spread in sub-Saharan Africa]]. In 2007, between 12% and 17% of infections in this region were attributed to medical syringe use.<ref name=UnsafeInjection2009>{{cite journal |vauthors=Reid SR |title=Injection drug use, unsafe medical injections, and HIV in Africa: a systematic review |journal=[[Harm Reduction Journal]] |volume=6 |page=24 |date=August 2009 |pmid=19715601 |pmc=2741434 |doi=10.1186/1477-7517-6-24 |doi-access=free }}</ref> The [[World Health Organization]] estimates the risk of transmission as a result of a medical injection in Africa at 1.2%.<ref name=UnsafeInjection2009/> Risks are also associated with invasive procedures, assisted delivery, and dental care in this area of the world.<ref name=UnsafeInjection2009/> People giving or receiving [[tattoo]]s, [[body piercing|piercings]], and [[scarification]] are theoretically at risk of infection but no confirmed cases have been documented.<ref name=CDCBasics2012>{{cite web |title=Basic Information about HIV and AIDS|url=https://www.cdc.gov/hiv/topics/basic/|website=Center for Disease Control and Prevention |date=April 2012 |url-status=live |archive-url=https://web.archive.org/web/20170618025129/https://www.cdc.gov/hiv/topics/basic/ |archive-date=June 18, 2017 }}</ref> It is not possible for [[mosquito]]es or other insects to transmit HIV.<ref name="C4Wauto-8503951">{{cite web |url=http://www.rci.rutgers.edu/%7Einsects/aids.htm |title=Why Mosquitoes Cannot Transmit AIDS |website=[[Rutgers University]] |id=New Jersey Agricultural Experiment Station Publication No. H-40101-01-93 |date=June 1, 2010 |access-date=March 29, 2014 |first=Wayne J. |last=Crans |archive-url=https://web.archive.org/web/20140329183346/http://www.rci.rutgers.edu/~insects/aids.htm |archive-date=March 29, 2014}}</ref> === Mother-to-child === {{main|HIV and pregnancy|HIV and breastfeeding}} HIV can be transmitted from mother to child during pregnancy, during delivery, or through breast milk, resulting in the baby also contracting HIV.<ref name=TransmissionM2007/><ref>{{cite web |url=https://www.hiv.gov/hiv-basics/hiv-prevention/reducing-mother-to-child-risk/preventing-mother-to-child-transmission-of-hiv |title=Preventing Mother-to-Child Transmission of HIV |website=HIV.gov |access-date=December 8, 2017 |archive-url=https://web.archive.org/web/20171209044313/https://www.hiv.gov/hiv-basics/hiv-prevention/reducing-mother-to-child-risk/preventing-mother-to-child-transmission-of-hiv |archive-date=December 9, 2017 |url-status=live }}</ref> As of 2008, vertical transmission accounted for about 90% of cases of HIV in children.<ref name=Mother2010/> In the absence of treatment, the risk of transmission before or during birth is around 20%, and in those who also breastfeed 35%.<ref name=Mother2010/> Treatment decreases this risk to less than 5%.<ref>{{cite web |title=Mother-to-child transmission of HIV |url=https://www.who.int/hiv/topics/mtct/en/ |website=[[World Health Organization]] |access-date=December 27, 2019 |archive-url=https://web.archive.org/web/20191018093154/https://www.who.int/hiv/topics/mtct/en/ |archive-date=October 18, 2019 |url-status=dead }}</ref> Antiretrovirals when taken by either the mother or the baby decrease the risk of transmission in those who do breastfeed.<ref>{{cite journal |vauthors=White AB, Mirjahangir JF, Horvath H, Anglemyer A, Read JS |title=Antiretroviral interventions for preventing breast milk transmission of HIV |journal=The Cochrane Database of Systematic Reviews |volume=2014 |issue=10 |page=CD011323 |date=October 2014 |pmid=25280769 |doi=10.1002/14651858.CD011323|pmc=10576873 }}</ref> If blood contaminates food during [[pre-chewing]] it may pose a risk of transmission.<ref name=CDCBasics2012/> If a woman is untreated, two years of breastfeeding results in an HIV/AIDS risk in her baby of about 17%.<ref name=WHO2011Breast>{{cite web |title=Infant feeding in the context of HIV |url=https://www.who.int/elena/titles/bbc/hiv_infant_feeding/en/ |website=[[World Health Organization]] |access-date=March 9, 2017 |date=April 2011 |url-status=dead |archive-url=https://web.archive.org/web/20170309062212/http://www.who.int/elena/titles/bbc/hiv_infant_feeding/en/ |archive-date=March 9, 2017 }}</ref> Due to the increased risk of death without breastfeeding in many areas in the developing world, the World Health Organization recommends either exclusive breastfeeding or the provision of safe formula.<ref name=WHO2011Breast/> All women known to be HIV-positive should be taking lifelong antiretroviral therapy.<ref name=WHO2011Breast/> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. 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