The Updated HIV Prevention Guidelines

Male latex condoms are still the best strategy for reducing the spread of HIV infection.

In a recent guideline update published by Mazzaro et al in the journal Clinical Infectious Diseases, authors reviewed various new strategies for prevention of the spread of HIV.¹

The last update to the HIV prevention guideline, published in 2006,² requires an update due to the validation of new techniques to reduce the risk of HIV transmission, including preexposure prophylaxis (PrEP) and male circumcision.¹

The incidence of new HIV infections in industrialized countries is falling, but the reduction in new cases have not extended to all countries. In sub-Saharan Africa, approximately 4 in 10 new HIV infections occur among people between the ages of 15 and 24 years.¹

Barrier protection remains underused, even in industrialized countries. In 2007 alone, the Centers for Disease Control (CDC) reported 1.1 million new diagnoses of chlamydia in the United States.³

Condoms

Barrier protection using latex condoms reduces the risk of spreading HIV, as well as chlamydia, gonorrhea, syphilis, genital human papilloma virus (HPV), trichomoniasis, and possibly herpes simplex virus—2 (HSV-2). The protection is not perfect, however, as barriers only reduce the risk of transmission of HIV between serodiscordant partners by 80%.⁴

Polyurethane condoms and other synthetic non-latex condoms may provide protection against HIV infection, although some evidence suggests that certain types of non-latex condoms may not protect as well against pregnancy and generally have higher rates of breakage.⁵

Female condoms have recently been redesigned with a modified shape and seam that reduces the risk of mechanical failure, although female condoms are generally less reliable than male latex condoms.^6,7

Circumcision

Studies in Africa, including countries such as Uganda, South Africa, and Kenya, indicate that male circumcision reduced the risk of HIV acquisition by 58% over a 2-year period. Similar studies show a reduction in the rate of genital herpes acquisition, HPV infection, and trichomoniasis infection among circumcised men. Importantly, however, circumcision is not a substitute for barrier protection.^1,8

Topical Products

Trials of polyanionic gels, which are thought to reduce the risk of HIV entry when used vaginally, have had disappointing results. In 1 trial, a gel called PRO 2000 reduced the risk of HIV acquisition by 30% when used with barrier protection. That initial result, however, was not statistically significant and a larger trial showed no reduction in the risk of transmission.⁹

To date, only 1% tenofovir gel has been shown to be consistently effective in reducing the risk of HIV transmission. In a study of women in South Africa, tenofovir gel 1% reduced the risk of HIV acquisition by 39% and reduced the risk of HSV-2 infection by 51% over a median of 30 months when applied intravaginally in the 12 hours before or 2 hours after intercourse.^10,11

Similarly, PrEP with tenofovir-emtricitabine oral tablets has been shown to reduce the risk of HIV transmission by 92%, with an overall 42% reduction in the incidence of HIV infection with use of PrEP versus nonuse.^1,12

Vaccinations

All people with HIV should receive a hepatitis B vaccination because the clinical course of hepatitis B tends to accelerate in patients coinfected with HIV. In addition, hepatitis A vaccination is recommended for men who have sex with men and users of illegal injected drugs. Unfortunately, efforts in developing an effective HIV vaccine have been unsuccessful.¹

Conclusion

Despite several interventions for reducing the risk of HIV infection, including male circumcision, use of 1% tenofovir gel, and PrEP treatment, consistent use of barrier protection with male latex condoms is still the best strategy for reducing the risk of HIV infection.

References:

• Marrazzo JM, Cates W. Interventions to prevent sexually transmitted infections, including HIV infection. Clin Infect Dis. 2011;53(Suppl 3):S64-S78.
• Centers for Disease Control and Prevention, Workowski KA, Berman SM. Sexually transmitted diseases treatment guidelines, 2006. MMWR Recomm Rep. 2006;55(RR-11):1-94
• Centers for Disease Control and Prevention (CDC). Chlamydia screening among sexually active young female enrollees of health plans--United States, 2000-2007. MMWR Morb Mortal Wkly Rep. 2009;58(14):362-365.
• Weller S, Davis K. Condom effectiveness in reducing heterosexual HIV transmission. Cochrane Database Syst Rev. 2002.
• Gallo MF, Grimes DA, Lopez LM, Schulz KF. Non-latex versus latex male condoms for contraception. Cochrane Database Syst Rev. 2006.
• Vijayakumar G, Mabude Z, Smit J, Beksinska M, Lurie M. A review of female-condom effectiveness: patterns of use and impact on protected sex acts and STI incidence. Int J STD AIDS. 2006;17(10):652-659.
• Minnis AM, Padian NS. Effectiveness of female controlled barrier methods in preventing sexually transmitted infections and HIV: current evidence and future research directions. Sex Transm Infect. 2005;81(3):193-200.
• Bailey RC, Moses S, Parker CB, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. Lancet. 2007;369(9562):643-656.
• Abdool Karim SS, Richardson BA, Ramjee G, et al. Safety and effectiveness of BufferGel and 0.5% PRO2000 gel for the prevention of HIV infection in women. AIDS. 2011;25(7):957-966.
• Peterson L, Taylor D, Roddy R, et al. Tenofovir disoproxil fumarate for prevention of HIV infection in women: a phase 2, double-blind, randomized, placebo-controlled trial. PLoS Clin Trials. 2007;2(5):e27.
• Abdool Karim Q, Abdool Karim SS, Frohlich JA, et al. Effectiveness and safety of tenofovir gel, an antiretroviral microbicide, for the prevention of HIV infection in women. Science. 2010;329(5996):1168-1174.
• Grant RM, Lama JR, Anderson PL, et al. Preexposure chemoprophylaxis for HIV prevention in men who have sex with men. N Engl J Med. 2010;363(27):2587-2599.