The Updated HIV Prevention Guidelines

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

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.