HIV prevention refers to practices that aim to prevent the spread of the human immunodeficiency virus (HIV). HIV prevention practices may be undertaken by individuals to protect their own health and the health of those in their community, or may be instituted by governments and community-based organizations as public health policies. Prevention can include a lot of different combinations of biomedical strategies and great community-based interventions like education and testing through outreach programs.
Prevention strategies Interventions for the prevention of HIV include the use of:
Barrier methods, such as the use of condoms or dental dams during sexual activity Antiretroviral medicines or antiretroviral therapy (ART) Pre-exposure prophylaxis Post-exposure prophylaxis Voluntary male circumcision (see also Circumcision and HIV) Microbicides for sexually transmitted diseases Low dead space syringes
The consistent, correct use of condoms is one proven method for preventing the spread of HIV during sexual intercourse. In high income countries, Prevention of Mother to Child Transmission Programs (PMTC) including HIV testing of pregnant women, antiretroviral treatment, counselling about infant feeding, and safe obstetric practices (avoiding invasive procedures) have reduced mother-to-child transmission to less than 1%.
Treatment as prevention (TasP) is also effective; in sero-different couples (where one partner is HIV-positive and the other is HIV negative), HIV is significantly less likely to be transmitted to the uninfected partner if the HIV positive partner is on treatment. It is now known that an if HIV-positive person has an undetectable viral load, there is no risk of HIV transmission to a sexual partner.
Increased risk of contracting HIV correlates with the presence of co-infections, particularly other sexually transmissible infections. Medical professionals recommend treatment or prevention of other infections such as herpes, hepatitis A, hepatitis B, hepatitis C, human papillomavirus, syphilis, gonorrhea, and tuberculosis as an indirect way to prevent the spread of HIV infection. Doctors treat these conditions with pharmaceutical interventions and/or vaccination. Nevertheless, it is not known if treating other sexually transmitted infections on a population scale is effective in preventing HIV.
Harm reduction and social strategies Harm reduction is defined as "policies, programmes and practices that aim to minimise negative health, social and legal impacts associated with drug use, drug policies and drug laws". The World Health Organization (WHO) recognizes that harm reduction is central to the prevention of HIV amongst people who inject drugs (PWID) and their sexual and drug using partners. Social strategies do not require any drug or object to be effective, but rather require persons to change their behaviors to gain protection from HIV. Some social strategies include:
Needle-and-syringe programmes Supervised injection site Sex education LGBT sex education Safe sex Serosorting Sexual abstinence
Each of these strategies has widely differing levels of efficacy, social acceptance, and acceptance in the medical and scientific communities.
Populations who access HIV testing are less likely to engage in behaviors with high risk of contracting HIV, so HIV testing is almost always a part of any strategy to encourage people to change their behaviors to become less likely to contract HIV. Over 60 countries impose some form of travel restriction, either for short or long-term stays, for people infected with HIV.
Advertising and campaigns Persuasive messages delivered through health advertising and social marketing campaigns which are designed to educate people about the risks of HIV/AIDS and simple prevention strategies are also an important way of preventing HIV. These persuasive messages have successfully increased people's knowledge about HIV. More importantly, information sent out through advertising and social marketing also proves to be effective in promoting more favorable attitudes and intentions toward future condom use, though they did not bring significant change in actual behaviors except those were targeting at specific behavioral skills.
A 2020 systematic review of 16 studies found that financial education improved self-efficacy and lowered vulnerability to HIV in young people in low and middle income countries. Many of the studies in the review combined financial education with sexual health education and/or counselling.
Research in health communication also found that importance of advocating critical skills and informing available resources are higher for people with lower social power, but not necessarily true for people with more power. African American audiences need to be educated about strategies they could take to efficiently manage themselves in health behaviors such as mood control, management of drugs, and proactive planning for sexual behaviors. However, these things are not as important for European Americans.
Sexual contact
Condoms and gels
Consistent condom use reduces the risk of heterosexual HIV transmission by about 80% over the long-term. Where one partner of a couple has HIV infection, consistent condom use results in rates of HIV infection for the uninfected person below 1% per year. Some data support the equivalence of internal condoms to latex condoms, but the evidence is not definitive. As of January 2019, condoms are available inside 30% of prisons globally.Moazen, B, Owusu, PN, Wiessner, P and Stöver, H. (2019), Coverage and Barriers Towards Condom Provision in Prisons: A Review of the EvidenceAvailability, Coverage and Barriers Towards Condom Provision in Prisons: A Review of the EvidenceInstitut für Suchtforschung (ISFF), Frankfurt, University of Applied Sciences. Use of the spermicide nonoxynol-9 may increase the risk of transmission because it causes vaginal and rectal irritation. A vaginal gel containing tenofovir, a reverse transcriptase inhibitor, when used immediately before sex, was shown to reduce infection rates by roughly 40% among African women.
Voluntary male circumcision
Studies conducted in sub-Saharan Africa have found that circumcision reduces the risk of HIV infection in heterosexual men between 38 and 66% over two years. Based on these studies, the World Health Organization and UNAIDS both recommended male circumcision as a method of preventing female-to-male HIV transmission in 2007. Whether it protects against male-to-female transmission is disputed and whether it is of benefit in developed countries and among men who have sex with men is undetermined. For men who have sex with men there is some evidence that the penetrative partner has a lower chance of contracting HIV. Some experts fear that a lower perception of vulnerability among circumcised men may result in more sexual risk-taking behavior, thus negating its preventive effects. Women who have undergone female genital cutting have an increased risk of HIV.
The African studies on which this information is based have been criticized for methodological flaws. Svoboda and Howe compare them to the "lowest common denominator", citing "selection bias, randomization bias, experimenter bias, inadequate blinding, participant expectation bias, lack of placebo control, inadequate equipoise, excessive attrition of subjects, failure to investigate non-sexual HIV transmission, lead time bias, and time-out discrepancy." In addition, the 60% figure for risk reduction is dismissed as relative and misleading, with an absolute figure of only 1.3%, which is considered effectively meaningless given the "background noise produced by numerous sources of bias". They also point out that the United States has both the highest rates of circumcision and HIV/STD infections in the industrialized world, casting serious doubt that the former prevents the latter. There are also major epidemiological differences between regions: in Africa, HIV is commonly spread via inadequate infection prevention practices in health clinics, while in the US, the primary routes of infection are sharing equipment amongst people who use drugs and condomless anal intercourse among MSM. Additional criticisms are offered by George Hill: "Our results clearly show that these African CRFs were methodologically flawed from start to finish... From the start, there was almost nothing correct with these studies. It was quite clear that these studies were unethical. They would never have been approved by a single ethics committee in the United States."
Education and health promotion Programs encouraging sexual abstinence do not appear to affect subsequent HIV risk in high-income countries. Evidence for a benefit from peer education is equally poor. Comprehensive sexual education provided at school may decrease high risk behavior. A substantial minority of young people continue to engage in high-risk practices despite HIV/AIDS knowledge, underestimating their own risk of becoming infected with HIV.
Before exposure Early treatment of HIV-infected people with antiretrovirals protected 96% of partners from infection.National Institute of Allergy and Infectious Diseases (NIAID), "Treating HIV-infected People with Antiretrovirals Protects Partners from Infection", NIH News, 2011 May Pre-exposure prophylaxis with a daily dose of tenofovir with or without emtricitabine is effective in a number of groups, including men who have sex with men, couples where one is HIV positive, and young heterosexuals in Africa. Within the MSM community, the greatest barrier to PrEP use has been the stigma surrounding HIV and gay men. Gay men on PrEP have experienced "slut-shaming". Numerous other barriers were identified, including lack of quality LGBTQ care, cost, and adherence to medication use.
Universal precautions within the health-care environment are believed to be effective in decreasing the risk of HIV. Intravenous drug use is an important risk factor and harm reduction strategies such as needle-exchange programmes and opioid substitution therapy appear effective in decreasing this risk.
Needle exchange programs (also known as syringe exchange programs) are effective in preventing HIV among IDUs and in the broader community. Pharmacy sales of syringes and physician prescription of syringes have been also found to reduce HIV risk. Supervised injection facilities are also understood to address HIV risk in the most-at-risk populations. Multiple legal and attitudinal barriers limit the scale and coverage of these "harm reduction" programs in the United States and elsewhere around the world.
The American Centers for Disease Control and Prevention (CDC) conducted a study in partnership with the Thailand Ministry of Public Health to ascertain the effectiveness of providing people who inject drugs illicitly with daily doses of the antiretroviral drug tenofovir as a prevention measure. The results of the study revealed a 48.9% reduced incidence of the virus among the group of subjects who received the drug, in comparison to the control group who received a placebo. The principal investigator of the study stated in the Lancet medical journal: "We now know that pre-exposure prophylaxis can be a potentially vital option for HIV prevention in people at very high risk for infection, whether through sexual transmission or injecting drug use."
After exposure