How Is HIV Transmitted?

Table of ContentsView AllTable of ContentsVaginal SexOral SexInjecting Drug UseBlood Transfusions and TransplantsPregnancyOther Possible CausesFactors that Increase Risk

Table of ContentsView All

View All

Table of Contents

Vaginal Sex

Oral Sex

Injecting Drug Use

Blood Transfusions and Transplants

Pregnancy

Other Possible Causes

Factors that Increase Risk

HIVis a virus that can be transmitted from someone with HIV to someone without through body fluids like semen, blood, vaginal secretions, and breast milk. HIV is most commonly passed during unprotected sex, primarily anal and vaginal sex, but is also effectively transmitted through shared needles.

HIV can also be passed from mother to child via the placenta during pregnancy or during childbirth, due to exposure to blood or vaginal fluid, or while breastfeeding.

Theresa Chiechi / Verywell

Some modes of transmission are more efficient than others. In order for HIV to be transmitted, the virus needs to come into contact with porousmucous membranes(such as those found in the rectum and vagina), pass through breaks and tears in tissues (such as can occur during intercourse), or enter the bloodstream directly (such as throughshared needles).

Moreover, there is needs to be ample quantities of the virus to breach the body’sfrontline immune defenses. This is why HIV cannot be passed through saliva, the environment of which is hostile to the virus, or when the virus is fully suppressed (undetectable) in anHIV-positiveperson onantiretroviral therapy.

What Is HIV?Human immunodeficiency virus (HIV)is a type of virus that preferentially targets white blood cells calledCD4 T-cells. By killing more and more of these cells, the body’s immune defenses are weakened and eventuallycompromised. If an untreated HIV infection progresses, there is ongoing damage to immune defense cells. As this happens, the body becomes increasingly less able to fight off infections. When this happens, a person is said to haveacquired immunodeficiency syndrome (AIDS).

What Is HIV?

Human immunodeficiency virus (HIV)is a type of virus that preferentially targets white blood cells calledCD4 T-cells. By killing more and more of these cells, the body’s immune defenses are weakened and eventuallycompromised. If an untreated HIV infection progresses, there is ongoing damage to immune defense cells. As this happens, the body becomes increasingly less able to fight off infections. When this happens, a person is said to haveacquired immunodeficiency syndrome (AIDS).

There are four conditions that must be met for an HIV infection to take place:

What Is Considered an Open Wound for HIV Transmission?

HIV Doctor Discussion GuideGet our printable guide for your next doctor’s appointment to help you ask the right questions.Download PDFEmail AddressSign UpThank you, {{form.email}}, for signing up.There was an error. Please try again.

Get our printable guide for your next doctor’s appointment to help you ask the right questions.

Download PDF

Email AddressSign UpThank you, {{form.email}}, for signing up.There was an error. Please try again.

Sign Up

Thank you, {{form.email}}, for signing up.

There was an error. Please try again.

Anal Sex

Anal sexis the predominant means of HIV transmission in the United States, occurring at a rate 18 times greater than that of vaginal sex.There are a number of reasons as to why this is, not least of which is the fact that rectal tissues are more fragile and vulnerable to rupture than vaginal tissues.

These vulnerabilities help explain whyinfection ratesin the United States are highest amongmen who have sex with men (MSM).But the risk is not only limited to gay and bisexual men; anywhere from 16% to 33% of heterosexual couples engage in anal sex as well, often without condoms.

Studies suggest that the risk of HIV in a receptive anal partner is nearly twice that of the insertive partner (40.4% versus 21.7% respectively).

The risk is further increased if the insertive partner isuncircumcised, as microbes beneath the foreskin can increase the shedding (expulsion) of the virus into seminal fluids.

Vaginal sexis the second most common mode of HIV transmission in the United States. In many parts of the developing world, vaginal sex is the primary mode of transmission, with women disproportionately affected compared to men.

Women are more vulnerable for several reasons:

According to a 2018 review inCurrent HIV/AIDS Reports,women are twice as likely to get HIV from a male partner during vaginal intercourse than the other way around.

How STDs Increase the Risk of HIV

Oral sexis an inefficient way of transmitting HIV, whether it be oral-penile sex (“blowjobs”), oral-vaginal sex (cunnilingus), or oral-anal sex (“rimming”). The current scientific consensus is that HIV transmission among those who engage exclusively in oral sex is unlikely. The risk may not be zero, but most agree that it is edging close to that.

A 2014 study in the journalAIDSsuggests that the per-act risk of infection from oral sex between anHIV-negativereceptive partner and an HIV-positive insertive partner hovers between 0% and 0.4%.

This is not to suggest that people can have oral sex with impunity. Cuts, abrasions, and sores on the genitals or in the mouth can potentially increase the risk of infection, as can STDs ormenstruation(both of which promote HIV shedding).

Other STDs besides HIV can also be transmitted through oral sex, including chlamydia, gonorrhea,herpes,human papillomavirus (HPV), and syphilis. Getting an STD independently increases the risk of HIV.

Why Oral Sex Isn’t Really Safe Sex

Sharing injecting needles is an extremely effective way of transmitting HIV, directly inoculating the virus from the blood of one person into that of another.

Injecting drug use is today the third most common mode of transmission in the United States and is the primary mode of transmission in Russia and Central Asia, where the flow of illegal drugs remains largely unimpeded.

In the United States, the growingopioid crisishas spurred an increase in HIV infections. One of the most publicized HIV outbreaks occurred in 2015 when 79 infections were reported in the town of Austin, Indiana (population 4,295), all of which were attributed to the shared use of needles among recreationaloxymorphoneusers.

Even amonganabolic steroid users, there has been an increase in the number of people who share needles, with nearly one in 10 getting HIV according to a 2013 study in theBritish Journal of Medicine.

Opioid Drug Use and Hepatitis C

In the early days of the HIV epidemic in the 1980s to early 1990s, there were many people infected with HIV due to tainted blood transfusions. Prior to 1992, there were limited screening tools available to ensure that the U.S. blood supply, including clotting factors and plasma, was free of the virus.

That risk has fallen dramatically in recent decades due to advances in detection technologies and the universal screening of blood and tissue donations in the United States and other countries. This not only includes the screening of HIV but other bloodborne infections likehepatitis Bandhepatitis C.

The risk outside of the United States can vary dramatically. In South Africa, the country with the highest HIV incidence in the world, the transmission risk is closer to one of every 76,000 transfusions.

As with blood transfusions, the risk of mother-to-child HIV infection was high in the early years of the global pandemic. Today, the risk has dropped dramatically, even in hard-hit parts of Africa, due to routine HIV screening in pregnant people and the use ofantiretroviral drugsto prevent vertical (mother-to-child) transmission.

HIV can also be transmitted through breast milk, and, in the United States, people with HIV are routinely advised to avoid breastfeeding irrespective of whether they are on HIV therapy or have an undetectable viral load. (The same recommendations are not extended to the developing world, where the benefits of infant nutrition are seen to outweigh the risks.)

If HIV is left untreated, the risk of mother-child transmission during labor and childbirth is between 15% and 30% and between 15% and 20% during breastfeeding.

Annually, there are only about 150 cases of vertical transmissions in the United States, most often caused when a person presents at the hospital late in pregnancy or fails to adhere to HIV therapy.

HIV Symptoms Women Should Be Aware Of

There are other, less common causes of HIV transmission and several for which the risk of HIV is unlikely but possible. These include occupational exposure, dental procedures, body piercings and tattoos, and shared sex toys.

Can You Get a Tattoo While Pregnant?

Occupational Exposure

HIV transmission fromneedlestick injuriesor other occupational exposures can place healthcare workers at risk. With that said, the risk of HIV from a needlestick injury is less than one in 1,000, while contact with HIV-infected body fluids on intact skin is even lower.

To date, only 58 cases of occupational HIV transmissions have been confirmed. Others are believed to have been averted with a 28-day course of antiretrovirals called HIVpost-exposure prophylaxis (PEP).

What to Do If Accidentally Exposed to HIV

Dental Procedures

Back in the early days of the AIDS crisis, headlines were made when a Pennsylvania woman named Kimberly Bergalis claimed to have gotten HIV from a dental procedure. The claims were considered dubious given that Bergalis failed to report prior sexually transmitted infections.

Since that time, there have been several claims but no documented cases of HIV transmission among dental patients. Of eight cases reported among dentists, none have been confirmed as having been transferred during a dental procedure.

Body Piercings and Tattoos

While theoretically feasible, the risk of HIV frombody piercings and tattoosis low due to the licensing and strict regulation of practitioners within the industry. For its part, the CDC insists that the risk of HIV transmission is low to negligible.

Shared Sex Toys

Sex toys are generally regarded as a form of safer sex. With that said, shared insertive toys like dildos are regarded as potentially unsafe due to exposure to blood and other bodily fluids.

To date, the risk of HIV from shared toys remains unclear since toys are rarely the only form of sex a couple will engage in. The same applies tofistingand other sexual practices that disrupt or traumatize rectal or vaginal tissues. These activities can theoretically potentiate infection, but studies have yet to confirm this.

Ways HIV Cannot Be SpreadYou cannot get HIV from hugging, kissing, shaking hands, sharing utensils, drinking from fountains, mosquito bites, toilet seats, or sexual touching without body fluids.

Ways HIV Cannot Be Spread

You cannot get HIV from hugging, kissing, shaking hands, sharing utensils, drinking from fountains, mosquito bites, toilet seats, or sexual touching without body fluids.

8 Simple Steps to Prevent HIV

Factors that Increase Risk of Transmission

There are a number of factors that can significantly increase the risk of HIV transmission irrespective of the route of exposure:

US Cities With the Highest HIV Infection Rates

A Word From Verywell

Understanding the risks of HIV can help you build individual strategies to help prevent either getting or spreading HIV. This may involve theconsistent use of condomsand a reduction in the number of sex partners or the use of needle exchange programs and other harm reduction strategies if you inject drugs.

34 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Rodger A, Cambiano V, Bruun T, et al.Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study.Lancet.2019;393(10189):2428-2438. doi:10.1016/S0140-6736(19)30418-0Centers for Disease Control and Prevention.How HIV spreads.Baggaley R, White R, Boily C.HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention.International Journal of Epidemiology. 2010;39(4):1048-1063. doi:10.1093/ije/dyq057Beyrer C, Baral S, van Griensven F, et al.Global epidemiology of HIV infection in men who have sex with men.Lancet.2012;380(9839):367-77. doi:10.1016/S0140-6736(12)60821-6German D, Nguyen TQ, Ogbue CP, Flynn C.Condomless anal intercourse among males and females at high risk for heterosexual HIV infection.Sex Trans Dis. 2015;42(6):317-23. doi:10.1097/OLQ.0000000000000275Ramjee G, Daniels B.Women and HIV in sub-Saharan Africa.AIDS Res Ther. 2013;10(1):30. doi:10.1186/1742-6405-10-30Scully EP.Sex differences in HIV infection.Curr HIV/AIDS Rep. 2018;15(2):136-46. doi:10.1007/s11904-018-0383-2Liu C, Hungate B, Tobian A, et al.Male circumcision significantly reduces prevalence and load of genital anaerobic bacteria.mBio.2013;4(2):e00076-13. doi:10.1128/mBio.00076-13Becerra JC, Bildstein LS, Gach JS.Recent insights into the HIV/AIDS pandemic.Microb Cell. 2016;3(9):451-475. doi:10.15698/mic2016.09.529Patel P, Borkowf CB, Brooks JT, Lasry A, Lansky A, Mermin J.Estimating per-act HIV transmission risk: A systematic review.AIDS. 2014;28(10):1509-19. doi:10.1097/QAD.0000000000000298Jones J, Weiss K, Mermin J, et al.Proportion of incident human immunodeficiency virus cases among men who have sex with men attributable to gonorrhea and chlamydia: A modeling analysis.Sex Transmit Dis. 2019;46(6):357-63. doi:10.1097/OLQ.0000000000000980Beyrer C, Wirtz AL, O’Hara G, Léon N, Kazatchkine M.The expanding epidemic of HIV-1 in the Russian Federation.PLoS Med. 2017;14(11):e1002462. doi:10.1371/journal.pmed.1002462National Institute of Drug Abuse.HIV infection linked to injection use of oxymorphone in Indiana, 2014-2015.Hope V, McVeigh J, Marongui A, et al.Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance-enhancing drugs: a cross-sectional study.Br J Med.2013;3(9):e003027. doi:10.1136/bmjopen-2013-003207Centers for Disease Control and Prevention.HIV transmission through transfusion — Missouri and Colorado, 2008.MMWR.2010:59(41):1335-9.Vermeulen M, Lelie N, Coleman C, et al.Assessment of HIV transfusion transmission risk in South Africa: A 10‐year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes.Transfusion. 2019;59(1):267-76. doi:10.1111/trf.14959World Health Organization.Mother-to-child transmission of HIV.Centers for Disease Control and Prevention.HIV and breastfeeding.Teasdale CA, Marais BJ, Abrams EJ.HIV: Prevention of mother-to-child transmission.BMJ Clin Evid. 2011;2011:0909.Nesheim S, Harris LF, Lampe M.Elimination of perinatal HIV infection in the USA and other high-income countries: Achievements and challenges.Curr Opinion HIV AIDS. 2013;8(5):447-456. doi:10.1097/COH.0b013e3283636ccbCenters for Disease Control and Prevention.HIV and occupational exposure.Laheij AMGA, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ, European Oral Microbiology Workshop (EOMW) 2011.Healthcare-associated viral and bacterial infections in dentistry.J Oral Microbiol. 2012;4(1):17659. doi:10.3402/jom.v4i0.17659Rice CE, Maierhofer C, Fields KS, Ervin M, Lanza ST, Turner AN.Beyond anal sex: Sexual practices of men who have sex with men and associations with HIV and other sexually transmitted infections.J Sexual Medi. 2016;13(3):374-82. doi:10.1016/j.jsxm.2016.01.001HIV.gov.How is HIV transmitted?Sullivan KM, Dawson Rose C, Phillips JC, et al.Sexual transmission-risk behaviour among HIV-positive persons: a multisite study using social action theory.J Adv Nurs. 2017;73(1):162-76. doi:10.1111/jan.13087Baeten JM, Kahle E, Lingappa JR, et al.Genital HIV-1 RNA predicts risk of heterosexual HIV-1 transmission.Sci Trans Med. 2011;3(77):77ra29. doi:10.1126/scitranslmed.3001888Marcus U, Schmidt AJ, Hamouda O.HIV serosorting among HIV-positive men who have sex with men is associated with increased self-reported incidence of bacterial sexually transmissible infections.Sex Health. 2011;8(2):184. doi:10.1071/SH10053Schecke H, Lea T, Bohn A, et al.Crystal methamphetamine use in sexual settings among German men who have sex with men.Front Psychiatry. 2019;10:886. doi:10.3389/fpsyt.2019.00886Pathela P, Braunstein SL, Schillinger JA, Shepard C, Sweeney M, Blank S.Men who have sex with men have a 140-fold higher risk for newly diagnosed HIV and syphilis compared with heterosexual men in New York City.J Acquired Immune Defic Synd. 2011;58(4):408-16. doi:10.1097/QAI.0b013e318230e1caKalichman SC, Cherry C, Kalichman MO, et al.Sexual behaviors and transmission risks among people living with HIV: beliefs, perceptions, and challenges to using treatments as prevention.Arch Sex Behav. 2016;45(6):1421-30. doi:10.1007/s10508-015-0559-4Carballo-Diéguez A, Lentz C, Giguere R, Fuchs EJ, Hendrix CW.Rectal douching associated with receptive anal intercourse: A literature review.AIDS Behav. 2018;22(4):1288-94. doi:10.1007/s10461-017-1959-3Alcaide ML, Rodriquez VJ, Fischl MA, Jones DL, Weiss SM.Addressing intravaginal practices in women with HIV and at-risk for HIV infection, a mixed-methods pilot study.Int J Womens Health. 2017;9:123-32. doi:10.2147/IJWH.S125883Centers for Disease Control and Prevention.HIV Surveillance Report, 2014 Volume 26.Underhill K, Morrow KM, Colleran C, et al.Explaining the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention: A qualitative study of message framing and messaging preferences among us men who have sex with men.AIDS Behav. 2016;20(7):1514-26. doi:10.1007/s10461-015-1088-9

34 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Rodger A, Cambiano V, Bruun T, et al.Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study.Lancet.2019;393(10189):2428-2438. doi:10.1016/S0140-6736(19)30418-0Centers for Disease Control and Prevention.How HIV spreads.Baggaley R, White R, Boily C.HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention.International Journal of Epidemiology. 2010;39(4):1048-1063. doi:10.1093/ije/dyq057Beyrer C, Baral S, van Griensven F, et al.Global epidemiology of HIV infection in men who have sex with men.Lancet.2012;380(9839):367-77. doi:10.1016/S0140-6736(12)60821-6German D, Nguyen TQ, Ogbue CP, Flynn C.Condomless anal intercourse among males and females at high risk for heterosexual HIV infection.Sex Trans Dis. 2015;42(6):317-23. doi:10.1097/OLQ.0000000000000275Ramjee G, Daniels B.Women and HIV in sub-Saharan Africa.AIDS Res Ther. 2013;10(1):30. doi:10.1186/1742-6405-10-30Scully EP.Sex differences in HIV infection.Curr HIV/AIDS Rep. 2018;15(2):136-46. doi:10.1007/s11904-018-0383-2Liu C, Hungate B, Tobian A, et al.Male circumcision significantly reduces prevalence and load of genital anaerobic bacteria.mBio.2013;4(2):e00076-13. doi:10.1128/mBio.00076-13Becerra JC, Bildstein LS, Gach JS.Recent insights into the HIV/AIDS pandemic.Microb Cell. 2016;3(9):451-475. doi:10.15698/mic2016.09.529Patel P, Borkowf CB, Brooks JT, Lasry A, Lansky A, Mermin J.Estimating per-act HIV transmission risk: A systematic review.AIDS. 2014;28(10):1509-19. doi:10.1097/QAD.0000000000000298Jones J, Weiss K, Mermin J, et al.Proportion of incident human immunodeficiency virus cases among men who have sex with men attributable to gonorrhea and chlamydia: A modeling analysis.Sex Transmit Dis. 2019;46(6):357-63. doi:10.1097/OLQ.0000000000000980Beyrer C, Wirtz AL, O’Hara G, Léon N, Kazatchkine M.The expanding epidemic of HIV-1 in the Russian Federation.PLoS Med. 2017;14(11):e1002462. doi:10.1371/journal.pmed.1002462National Institute of Drug Abuse.HIV infection linked to injection use of oxymorphone in Indiana, 2014-2015.Hope V, McVeigh J, Marongui A, et al.Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance-enhancing drugs: a cross-sectional study.Br J Med.2013;3(9):e003027. doi:10.1136/bmjopen-2013-003207Centers for Disease Control and Prevention.HIV transmission through transfusion — Missouri and Colorado, 2008.MMWR.2010:59(41):1335-9.Vermeulen M, Lelie N, Coleman C, et al.Assessment of HIV transfusion transmission risk in South Africa: A 10‐year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes.Transfusion. 2019;59(1):267-76. doi:10.1111/trf.14959World Health Organization.Mother-to-child transmission of HIV.Centers for Disease Control and Prevention.HIV and breastfeeding.Teasdale CA, Marais BJ, Abrams EJ.HIV: Prevention of mother-to-child transmission.BMJ Clin Evid. 2011;2011:0909.Nesheim S, Harris LF, Lampe M.Elimination of perinatal HIV infection in the USA and other high-income countries: Achievements and challenges.Curr Opinion HIV AIDS. 2013;8(5):447-456. doi:10.1097/COH.0b013e3283636ccbCenters for Disease Control and Prevention.HIV and occupational exposure.Laheij AMGA, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ, European Oral Microbiology Workshop (EOMW) 2011.Healthcare-associated viral and bacterial infections in dentistry.J Oral Microbiol. 2012;4(1):17659. doi:10.3402/jom.v4i0.17659Rice CE, Maierhofer C, Fields KS, Ervin M, Lanza ST, Turner AN.Beyond anal sex: Sexual practices of men who have sex with men and associations with HIV and other sexually transmitted infections.J Sexual Medi. 2016;13(3):374-82. doi:10.1016/j.jsxm.2016.01.001HIV.gov.How is HIV transmitted?Sullivan KM, Dawson Rose C, Phillips JC, et al.Sexual transmission-risk behaviour among HIV-positive persons: a multisite study using social action theory.J Adv Nurs. 2017;73(1):162-76. doi:10.1111/jan.13087Baeten JM, Kahle E, Lingappa JR, et al.Genital HIV-1 RNA predicts risk of heterosexual HIV-1 transmission.Sci Trans Med. 2011;3(77):77ra29. doi:10.1126/scitranslmed.3001888Marcus U, Schmidt AJ, Hamouda O.HIV serosorting among HIV-positive men who have sex with men is associated with increased self-reported incidence of bacterial sexually transmissible infections.Sex Health. 2011;8(2):184. doi:10.1071/SH10053Schecke H, Lea T, Bohn A, et al.Crystal methamphetamine use in sexual settings among German men who have sex with men.Front Psychiatry. 2019;10:886. doi:10.3389/fpsyt.2019.00886Pathela P, Braunstein SL, Schillinger JA, Shepard C, Sweeney M, Blank S.Men who have sex with men have a 140-fold higher risk for newly diagnosed HIV and syphilis compared with heterosexual men in New York City.J Acquired Immune Defic Synd. 2011;58(4):408-16. doi:10.1097/QAI.0b013e318230e1caKalichman SC, Cherry C, Kalichman MO, et al.Sexual behaviors and transmission risks among people living with HIV: beliefs, perceptions, and challenges to using treatments as prevention.Arch Sex Behav. 2016;45(6):1421-30. doi:10.1007/s10508-015-0559-4Carballo-Diéguez A, Lentz C, Giguere R, Fuchs EJ, Hendrix CW.Rectal douching associated with receptive anal intercourse: A literature review.AIDS Behav. 2018;22(4):1288-94. doi:10.1007/s10461-017-1959-3Alcaide ML, Rodriquez VJ, Fischl MA, Jones DL, Weiss SM.Addressing intravaginal practices in women with HIV and at-risk for HIV infection, a mixed-methods pilot study.Int J Womens Health. 2017;9:123-32. doi:10.2147/IJWH.S125883Centers for Disease Control and Prevention.HIV Surveillance Report, 2014 Volume 26.Underhill K, Morrow KM, Colleran C, et al.Explaining the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention: A qualitative study of message framing and messaging preferences among us men who have sex with men.AIDS Behav. 2016;20(7):1514-26. doi:10.1007/s10461-015-1088-9

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Rodger A, Cambiano V, Bruun T, et al.Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study.Lancet.2019;393(10189):2428-2438. doi:10.1016/S0140-6736(19)30418-0Centers for Disease Control and Prevention.How HIV spreads.Baggaley R, White R, Boily C.HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention.International Journal of Epidemiology. 2010;39(4):1048-1063. doi:10.1093/ije/dyq057Beyrer C, Baral S, van Griensven F, et al.Global epidemiology of HIV infection in men who have sex with men.Lancet.2012;380(9839):367-77. doi:10.1016/S0140-6736(12)60821-6German D, Nguyen TQ, Ogbue CP, Flynn C.Condomless anal intercourse among males and females at high risk for heterosexual HIV infection.Sex Trans Dis. 2015;42(6):317-23. doi:10.1097/OLQ.0000000000000275Ramjee G, Daniels B.Women and HIV in sub-Saharan Africa.AIDS Res Ther. 2013;10(1):30. doi:10.1186/1742-6405-10-30Scully EP.Sex differences in HIV infection.Curr HIV/AIDS Rep. 2018;15(2):136-46. doi:10.1007/s11904-018-0383-2Liu C, Hungate B, Tobian A, et al.Male circumcision significantly reduces prevalence and load of genital anaerobic bacteria.mBio.2013;4(2):e00076-13. doi:10.1128/mBio.00076-13Becerra JC, Bildstein LS, Gach JS.Recent insights into the HIV/AIDS pandemic.Microb Cell. 2016;3(9):451-475. doi:10.15698/mic2016.09.529Patel P, Borkowf CB, Brooks JT, Lasry A, Lansky A, Mermin J.Estimating per-act HIV transmission risk: A systematic review.AIDS. 2014;28(10):1509-19. doi:10.1097/QAD.0000000000000298Jones J, Weiss K, Mermin J, et al.Proportion of incident human immunodeficiency virus cases among men who have sex with men attributable to gonorrhea and chlamydia: A modeling analysis.Sex Transmit Dis. 2019;46(6):357-63. doi:10.1097/OLQ.0000000000000980Beyrer C, Wirtz AL, O’Hara G, Léon N, Kazatchkine M.The expanding epidemic of HIV-1 in the Russian Federation.PLoS Med. 2017;14(11):e1002462. doi:10.1371/journal.pmed.1002462National Institute of Drug Abuse.HIV infection linked to injection use of oxymorphone in Indiana, 2014-2015.Hope V, McVeigh J, Marongui A, et al.Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance-enhancing drugs: a cross-sectional study.Br J Med.2013;3(9):e003027. doi:10.1136/bmjopen-2013-003207Centers for Disease Control and Prevention.HIV transmission through transfusion — Missouri and Colorado, 2008.MMWR.2010:59(41):1335-9.Vermeulen M, Lelie N, Coleman C, et al.Assessment of HIV transfusion transmission risk in South Africa: A 10‐year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes.Transfusion. 2019;59(1):267-76. doi:10.1111/trf.14959World Health Organization.Mother-to-child transmission of HIV.Centers for Disease Control and Prevention.HIV and breastfeeding.Teasdale CA, Marais BJ, Abrams EJ.HIV: Prevention of mother-to-child transmission.BMJ Clin Evid. 2011;2011:0909.Nesheim S, Harris LF, Lampe M.Elimination of perinatal HIV infection in the USA and other high-income countries: Achievements and challenges.Curr Opinion HIV AIDS. 2013;8(5):447-456. doi:10.1097/COH.0b013e3283636ccbCenters for Disease Control and Prevention.HIV and occupational exposure.Laheij AMGA, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ, European Oral Microbiology Workshop (EOMW) 2011.Healthcare-associated viral and bacterial infections in dentistry.J Oral Microbiol. 2012;4(1):17659. doi:10.3402/jom.v4i0.17659Rice CE, Maierhofer C, Fields KS, Ervin M, Lanza ST, Turner AN.Beyond anal sex: Sexual practices of men who have sex with men and associations with HIV and other sexually transmitted infections.J Sexual Medi. 2016;13(3):374-82. doi:10.1016/j.jsxm.2016.01.001HIV.gov.How is HIV transmitted?Sullivan KM, Dawson Rose C, Phillips JC, et al.Sexual transmission-risk behaviour among HIV-positive persons: a multisite study using social action theory.J Adv Nurs. 2017;73(1):162-76. doi:10.1111/jan.13087Baeten JM, Kahle E, Lingappa JR, et al.Genital HIV-1 RNA predicts risk of heterosexual HIV-1 transmission.Sci Trans Med. 2011;3(77):77ra29. doi:10.1126/scitranslmed.3001888Marcus U, Schmidt AJ, Hamouda O.HIV serosorting among HIV-positive men who have sex with men is associated with increased self-reported incidence of bacterial sexually transmissible infections.Sex Health. 2011;8(2):184. doi:10.1071/SH10053Schecke H, Lea T, Bohn A, et al.Crystal methamphetamine use in sexual settings among German men who have sex with men.Front Psychiatry. 2019;10:886. doi:10.3389/fpsyt.2019.00886Pathela P, Braunstein SL, Schillinger JA, Shepard C, Sweeney M, Blank S.Men who have sex with men have a 140-fold higher risk for newly diagnosed HIV and syphilis compared with heterosexual men in New York City.J Acquired Immune Defic Synd. 2011;58(4):408-16. doi:10.1097/QAI.0b013e318230e1caKalichman SC, Cherry C, Kalichman MO, et al.Sexual behaviors and transmission risks among people living with HIV: beliefs, perceptions, and challenges to using treatments as prevention.Arch Sex Behav. 2016;45(6):1421-30. doi:10.1007/s10508-015-0559-4Carballo-Diéguez A, Lentz C, Giguere R, Fuchs EJ, Hendrix CW.Rectal douching associated with receptive anal intercourse: A literature review.AIDS Behav. 2018;22(4):1288-94. doi:10.1007/s10461-017-1959-3Alcaide ML, Rodriquez VJ, Fischl MA, Jones DL, Weiss SM.Addressing intravaginal practices in women with HIV and at-risk for HIV infection, a mixed-methods pilot study.Int J Womens Health. 2017;9:123-32. doi:10.2147/IJWH.S125883Centers for Disease Control and Prevention.HIV Surveillance Report, 2014 Volume 26.Underhill K, Morrow KM, Colleran C, et al.Explaining the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention: A qualitative study of message framing and messaging preferences among us men who have sex with men.AIDS Behav. 2016;20(7):1514-26. doi:10.1007/s10461-015-1088-9

Rodger A, Cambiano V, Bruun T, et al.Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study.Lancet.2019;393(10189):2428-2438. doi:10.1016/S0140-6736(19)30418-0

Centers for Disease Control and Prevention.How HIV spreads.

Baggaley R, White R, Boily C.HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention.International Journal of Epidemiology. 2010;39(4):1048-1063. doi:10.1093/ije/dyq057

Beyrer C, Baral S, van Griensven F, et al.Global epidemiology of HIV infection in men who have sex with men.Lancet.2012;380(9839):367-77. doi:10.1016/S0140-6736(12)60821-6

German D, Nguyen TQ, Ogbue CP, Flynn C.Condomless anal intercourse among males and females at high risk for heterosexual HIV infection.Sex Trans Dis. 2015;42(6):317-23. doi:10.1097/OLQ.0000000000000275

Ramjee G, Daniels B.Women and HIV in sub-Saharan Africa.AIDS Res Ther. 2013;10(1):30. doi:10.1186/1742-6405-10-30

Scully EP.Sex differences in HIV infection.Curr HIV/AIDS Rep. 2018;15(2):136-46. doi:10.1007/s11904-018-0383-2

Liu C, Hungate B, Tobian A, et al.Male circumcision significantly reduces prevalence and load of genital anaerobic bacteria.mBio.2013;4(2):e00076-13. doi:10.1128/mBio.00076-13

Becerra JC, Bildstein LS, Gach JS.Recent insights into the HIV/AIDS pandemic.Microb Cell. 2016;3(9):451-475. doi:10.15698/mic2016.09.529

Patel P, Borkowf CB, Brooks JT, Lasry A, Lansky A, Mermin J.Estimating per-act HIV transmission risk: A systematic review.AIDS. 2014;28(10):1509-19. doi:10.1097/QAD.0000000000000298

Jones J, Weiss K, Mermin J, et al.Proportion of incident human immunodeficiency virus cases among men who have sex with men attributable to gonorrhea and chlamydia: A modeling analysis.Sex Transmit Dis. 2019;46(6):357-63. doi:10.1097/OLQ.0000000000000980

Beyrer C, Wirtz AL, O’Hara G, Léon N, Kazatchkine M.The expanding epidemic of HIV-1 in the Russian Federation.PLoS Med. 2017;14(11):e1002462. doi:10.1371/journal.pmed.1002462

National Institute of Drug Abuse.HIV infection linked to injection use of oxymorphone in Indiana, 2014-2015.

Hope V, McVeigh J, Marongui A, et al.Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance-enhancing drugs: a cross-sectional study.Br J Med.2013;3(9):e003027. doi:10.1136/bmjopen-2013-003207

Centers for Disease Control and Prevention.HIV transmission through transfusion — Missouri and Colorado, 2008.MMWR.2010:59(41):1335-9.

Vermeulen M, Lelie N, Coleman C, et al.Assessment of HIV transfusion transmission risk in South Africa: A 10‐year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes.Transfusion. 2019;59(1):267-76. doi:10.1111/trf.14959

World Health Organization.Mother-to-child transmission of HIV.

Centers for Disease Control and Prevention.HIV and breastfeeding.

Teasdale CA, Marais BJ, Abrams EJ.HIV: Prevention of mother-to-child transmission.BMJ Clin Evid. 2011;2011:0909.

Nesheim S, Harris LF, Lampe M.Elimination of perinatal HIV infection in the USA and other high-income countries: Achievements and challenges.Curr Opinion HIV AIDS. 2013;8(5):447-456. doi:10.1097/COH.0b013e3283636ccb

Centers for Disease Control and Prevention.HIV and occupational exposure.

Laheij AMGA, Kistler JO, Belibasakis GN, Välimaa H, de Soet JJ, European Oral Microbiology Workshop (EOMW) 2011.Healthcare-associated viral and bacterial infections in dentistry.J Oral Microbiol. 2012;4(1):17659. doi:10.3402/jom.v4i0.17659

Rice CE, Maierhofer C, Fields KS, Ervin M, Lanza ST, Turner AN.Beyond anal sex: Sexual practices of men who have sex with men and associations with HIV and other sexually transmitted infections.J Sexual Medi. 2016;13(3):374-82. doi:10.1016/j.jsxm.2016.01.001

HIV.gov.How is HIV transmitted?

Sullivan KM, Dawson Rose C, Phillips JC, et al.Sexual transmission-risk behaviour among HIV-positive persons: a multisite study using social action theory.J Adv Nurs. 2017;73(1):162-76. doi:10.1111/jan.13087

Baeten JM, Kahle E, Lingappa JR, et al.Genital HIV-1 RNA predicts risk of heterosexual HIV-1 transmission.Sci Trans Med. 2011;3(77):77ra29. doi:10.1126/scitranslmed.3001888

Marcus U, Schmidt AJ, Hamouda O.HIV serosorting among HIV-positive men who have sex with men is associated with increased self-reported incidence of bacterial sexually transmissible infections.Sex Health. 2011;8(2):184. doi:10.1071/SH10053

Schecke H, Lea T, Bohn A, et al.Crystal methamphetamine use in sexual settings among German men who have sex with men.Front Psychiatry. 2019;10:886. doi:10.3389/fpsyt.2019.00886

Pathela P, Braunstein SL, Schillinger JA, Shepard C, Sweeney M, Blank S.Men who have sex with men have a 140-fold higher risk for newly diagnosed HIV and syphilis compared with heterosexual men in New York City.J Acquired Immune Defic Synd. 2011;58(4):408-16. doi:10.1097/QAI.0b013e318230e1ca

Kalichman SC, Cherry C, Kalichman MO, et al.Sexual behaviors and transmission risks among people living with HIV: beliefs, perceptions, and challenges to using treatments as prevention.Arch Sex Behav. 2016;45(6):1421-30. doi:10.1007/s10508-015-0559-4

Carballo-Diéguez A, Lentz C, Giguere R, Fuchs EJ, Hendrix CW.Rectal douching associated with receptive anal intercourse: A literature review.AIDS Behav. 2018;22(4):1288-94. doi:10.1007/s10461-017-1959-3

Alcaide ML, Rodriquez VJ, Fischl MA, Jones DL, Weiss SM.Addressing intravaginal practices in women with HIV and at-risk for HIV infection, a mixed-methods pilot study.Int J Womens Health. 2017;9:123-32. doi:10.2147/IJWH.S125883

Centers for Disease Control and Prevention.HIV Surveillance Report, 2014 Volume 26.

Underhill K, Morrow KM, Colleran C, et al.Explaining the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention: A qualitative study of message framing and messaging preferences among us men who have sex with men.AIDS Behav. 2016;20(7):1514-26. doi:10.1007/s10461-015-1088-9

Meet Our Medical Expert Board

Share Feedback

Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit

Was this page helpful?

Thanks for your feedback!

What is your feedback?OtherHelpfulReport an ErrorSubmit

What is your feedback?