Primary prevention
Condoms
The most widely available tool for prevention of HIV from sexual exposure is the male condom. Male condoms afford a high degree of protection: consistent and correct male condom use reduces HIV transmission by more than 90%.[39] Numerous studies have shown that the female condom is an acceptable method for many women and men, and is a valuable alternative for women whose partners refuse to use male condoms. Unlike the male condom, the female condom can be inserted some time before sex, and does not depend on the same degree of male co-operation for its successful use.
Oral pre-exposure prophylaxis (PrEP)
PrEP is an antiviral regimen that people who are at risk of HIV take to prevent HIV. Use of oral PrEP has increased significantly, particularly among gay men and other men who have sex with men (MSM).[40][41]
Studies have shown the effectiveness of daily oral PrEP in reducing the risk of HIV in adults who are at high risk for HIV. [
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Evidence from randomised controlled trials shows that oral tenofovir disoproxil/emtricitabine prophylaxis is highly effective in reducing the risk of HIV acquisition (75% to 86% reduction in the risk of HIV in MSM, depending on adherence level), and is considered safe with minimal adverse effects, in MSM, serodiscordant couples, and people who inject drugs.[42][43]
However, data from observational studies found that efficacy appears to be lower in real-world settings (60% reduction in the risk of HIV overall), possibly due to suboptimal PrEP adherence and interruptions to treatment supply, particularly among people <30 years of age and those in certain socioeconomic groups.[44]
The largest real-world study involving over 24,000 trial participants at sexual health clinics and conducted over three years found that the use of oral PrEP reduced the risk of getting HIV by 86% in real-world settings.[45]
A systematic review, including 20 randomised controlled trials with over 36,000 participants, found that oral PrEP was associated with a decreased risk of acquiring HIV in adults at increased risk of HIV acquisition, compared with placebo or no PrEP.[46]
There are data that provide reassurance that resistance is unlikely to occur in patients taking PrEP.[47]
Guideline recommendations for the use of oral PrEP vary. Consult your local guidelines for further information.
The World Health Organization strongly recommends offering oral PrEP (containing tenofovir disoproxil) as an additional prevention choice to people who are at substantial risk of HIV, as part of combination prevention approaches, based on high-certainty evidence.[48]
The US Centers for Disease Control and Prevention (CDC) recommends daily oral PrEP with tenofovir disoproxil/emtricitabine as a prevention option for: sexually active adults who report sexual behaviours that place them at substantial ongoing risk of HIV exposure and acquisition; and adults who inject drugs and report injection practices that place them at substantial ongoing risk of HIV exposure and acquisition. However, all sexually active adults should be informed about PrEP for prevention of HIV acquisition. Tenofovir disoproxil is recommended for both men and women; however, tenofovir alafenamide is recommended in men and transgender women only.[49] Long-term safety and tolerability of tenofovir alafenamide in cisgender men and transgender women has been demonstrated up to 144 weeks.[50] The efficacy of tenofovir alafenamide/emtricitabine has not been demonstrated in people with receptive vaginal exposure.[51] The safety and efficacy of other daily oral antiretroviral drugs for PrEP have not been studied extensively and are not currently recommended. HIV status should be assessed at least every 3 months so that people with incident infection promptly switch to treatment with antiretroviral therapy (ART).[49]
The American College of Obstetricians and Gynecologists (ACOG) supports CDC guidance, and recommends that obstetricians and gynaecologists discuss PrEP with all sexually active adults, not only those who are considered to be a substantial risk of HIV.[52]
The US Preventive Services Task Force recommends oral PrEP (i.e., tenofovir disoproxil/emtricitabine) in high-risk adults. This includes sexually active adults who have engaged in anal or vaginal sex in the past 6 months and have any of the following: a sexual partner who has HIV; a bacterial sexually-transmitted infection in the past 6 months; a history of inconsistent (or no) condom use with sex partner(s) whose HIV status is unknown. It also includes people who inject drugs and have a drug-injecting partner who has HIV or shares injection equipment. People who engage in transactional sex and transgender women should be considered for PrEP based on these criteria.[53]
Acute and chronic HIV must be excluded by symptom history and HIV testing immediately before any PrEP regimen is prescribed. Renal function should be assessed at baseline and monitored periodically during treatment.[49]
Regular STI testing and risk reduction counselling is recommended for those who use PrEP.[49]
In some studies, a rapid increase in the use of PrEP has resulted in an equally rapid decrease in consistent condom use.[54]
PrEP use among MSM may be indirectly associated with an increased risk of bacterial STIs as PrEP users have more anal sex partners and are more likely to engage in condomless anal sex.[55]
Doxycycline postexposure prophylaxis (doxy PEP) may be offered to gay, bisexual, and other men who have sex with men or transgender women who have had a bacterial STI (specifically syphilis, chlamydia, or gonorrhoea) diagnosed in the past 12 months, in order to prevent these infections. Doxy PEP is self-administered within 72 hours of having oral, vaginal, or anal sex.[56]
It should be noted that there has been a case report of tenofovir-susceptible, emtricitabine-resistant HIV acquisition despite high adherence to PrEP.[57][58]
PrEP did not significantly increase the risk of drug resistance mutations compared to placebo in one systematic review and meta-analysis.[59]
Consult your local drug information source for more information before prescribing oral PrEP.
Long-acting injectable PrEP
Cabotegravir extended-release injectable suspension is approved for use in at-risk adults for pre-exposure prophylaxis to reduce the risk of sexually-acquired HIV.[60]
Injections are administered every 2 months after the initial dose (two injections one month apart).
Patients can either start on intramuscular cabotegravir or take oral cabotegravir before switching to the intramuscular formulation to assess their tolerance of the drug.
A negative HIV test is required before treatment is started, and before each injection, in order to reduce the risk of developing drug resistance.
Long-acting injectable PrEP may address issues with adherence, and is an important prevention intervention for certain HIV populations.[61]
Long-acting injectable cabotegravir was found to lower HIV incidence compared to daily oral tenofovir disoproxil/emtricitabine when used for PrEP among men who have sex with men, transgender women, and cisgender women in sub-Saharan Africa in clinical trials.[62]
A systematic review and meta-analysis, which included four multisite randomised controlled trials, demonstrated a 70% risk reduction in HIV risk with long-acting injectable cabotegravir compared with daily oral PrEp.[63]
Guideline recommendations vary.
The WHO recommends long-acting cabotegravir as an additional prevention choice for people at substantial risk of HIV, as part of combination prevention approaches, based on moderate-certainty evidence.[64]
The Centers for Disease Control and Prevention recommends intramuscular cabotegravir injections as PrEP in adults who report sexual behaviours that place them at substantial ongoing risk of HIV exposure and acquisition.[49]
The US Preventive Services Task Force recommends intramuscular cabotegravir injections as an option for PrEP in high-risk adults (see above for criteria).[53]
Hepatotoxicity has been reported in a small number of people receiving cabotegravir, although similar levels were found among those receiving placebo. Consider liver function testing before and during treatment, and do not initiate treatment in people with advanced liver disease or acute viral hepatitis. Discontinue use if hepatotoxicity is confirmed. There are limited data on the use of cabotegravir in patients with hepatitis B or hepatitis C virus infection, and caution is advised.[64]
Consult your local drug information source for more information before prescribing long-acting injectable PrEP.
Pericoital (on-demand) PrEp
Pericoital (on-demand) oral PrEP may be considered instead of daily PrEP in MSM who have infrequent sexual exposures.
On-demand oral PrEP has been found to be effective in MSM who are at a high risk of HIV. However, a post-hoc analysis of the ANRS IPERGAY trial found that on-demand PrEP was also effective in MSM who were at a lower risk of HIV (i.e., periods of less frequent sexual intercourse defined as 5 episodes per month), with a 100% relative reduction of HIV incidence reported compared with placebo.[65]
Dapivirine vaginal ring
The dapirivine vaginal ring is approved for use in some countries with high disease burden to reduce the risk of HIV, in combination with safer sex practices, when oral PrEP is not used, cannot be used, or is not available. It is not approved in the US, but is approved in Europe. The ring is placed in the vagina and slowly releases dapivirine over a period of 28 days.
Current evidence shows that vaginal dapivirine microbicide probably reduces HIV acquisition in women who have sex with men. Other types of vaginal microbicides have not shown evidence of an affect on HIV acquisition.[66] [
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A systematic review of 18 randomised controlled trials in sub-Saharan Africa found that the dapivirine intravaginal ring reduced the risk of HIV transmission in women by 29%. Other microbicides had no effect.[67]
In a randomised, double-blind, placebo-controlled, phase 3 trial in sub-Saharan Africa, the dapivirine vaginal ring was associated with a lower rate of HIV acquisition compared with placebo.[68]
Guideline recommendations for the use of dapivirine vaginal ring vary. Consult your local guidelines for further information.
The WHO recommends the dapivirine vaginal ring may be offered as an additional prevention choice for women at substantial risk of HIV, and part of combination prevention approaches, based on moderate-certainty evidence.[69]
Consult your local drug information source for more information before prescribing the dapivirine vaginal ring.
Treatment as prevention
ART may be used to prevent HIV transmission. This is commonly known as undetectable=untransmittable (or U=U). Several large studies have shown that ART prevents HIV transmission in both heterosexual couples and MSM who maintain an undetectable viral load.[70][71][72][73][74][75]
Based on high-quality evidence, there is a negligible risk of sexual transmission of HIV when an HIV-positive sex partner adheres to ART and maintains a suppressed viral load <1000 copies/mL measured every 4-6 months. Sexual transmission of HIV has occurred when viral load was >200 copies/mL with ART or condoms alone were used, although the risk remains low and incidence of HIV transmission when viral load is 200 to 1000 copies/mL remains unclear.[76] One systematic review found that the risk of sexual transmission in people with viral loads between 200 copies/mL and 1000 copies/mL is almost zero.[77]
In light of this evidence, US guidelines currently recommend that physicians should inform patients that maintaining a HIV RNA level <200 copies/mL with ART prevents transmission to sexual partners. Another form of prevention should be used for the first 6 months of ART until an HIV RNA level of <200 copies/mL has been documented, with some experts recommending that sustained suppression is confirmed before assuming there is no risk of transmission.[78]
The Prevention Access Campaign has also released a consensus statement stating that the risk of HIV transmission from a person living with HIV who is on ART and has achieved undetectable viral load in their blood for at least 6 months is negligible to non-existent. Prevention Access Campaign: consensus statement Opens in new window
Immediate initiation of ART is recommended for the HIV-positive partner of HIV-serodiscordant couples, to prevent HIV transmission.[70][78] [
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Circumcision
Circumcision is associated with a reduction in HIV risk, and has been found to be protective for both homosexual and men who have sex with men.[79][80][81] [
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Other harm reduction methods
Convincing evidence exists for the benefit of needle exchange and clean syringes in the setting of methadone clinics, termed 'harm reduction', where HIV transmission risk is related to shared intravenous drug use equipment. In addition, the supply of HIV-free blood and blood products, as well as sterile needles and syringes for injections and universal precautions in hospitals, has much reduced nosocomial transmission of HIV.[82]
Vaccines
Secondary prevention
Sexual contacts
Sexual contacts of the patient should be enquired about. HIV status may already be known. If not, disclosure should be discussed. Patients may not be able to do this immediately but should be encouraged, especially in a situation where disclosure is linked to being able to practice safer sex. Practitioners may also offer to assist with disclosure under these circumstances and offer immediate testing for partners. There may be local regulations, and physicians should refer to these where appropriate. Public health officers may be able to facilitate partner notification.
Serodiscordant partners should be encouraged to be tested regularly, and can be protected from HIV by immediate initiation of antiretroviral therapy (ART) in the HIV-positive partner.[70][71][78][215] [
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Offspring
The physician should enquire whether the patient has children and how old they are. Their well-being and medical histories may give a clue to possible infection (if not already tested). If younger than 10 years of age and well and not previously tested, the physician may also advise having them tested. Children younger than 18 months of age may need a nucleic acid test (qualitative polymerase chain reaction). If still breastfeeding, advice against on-going transmission risk should be given and consideration to weaning (if older than 6 months of age) or switching to bottle/formula feeding.[216]
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