SECTION 1: HIV/SEXUAL DISEASE RISK ASSESSMENT
Ronald H. Goldschmidt, MD
In 1981, the Centers for Disease Control and Prevention (CDC) published the first report identifying individuals with what came to be known as acquired immunodeficiency syndrome (AIDS).[CDC 1981] Since then, scientists and clinicians have made great strides in understanding, treating, and preventing HIV disease. So, why is there now, in 2017, a renewed interest in preventing HIV disease? Despite testing, counseling, condoms, education, and other preventive measures, there are still about 40,000 cases of new HIV diagnosed in the United States every year.[HIV in the US (CDC) 2016] Most of these transmissions are preventable.
First-line prevention strategies involve not only safer sexual and drug use practices but also antiretroviral (ARV) drug therapy in 3 distinct ways: (1) treatment as prevention (treating persons with HIV to decrease the possibility that they can transmit HIV); (2) post-exposure prophylaxis (PEP); and (3) pre-exposure prophylaxis (PrEP) to HIV-uninfected persons at risk.
Treatment as Prevention. Effective ARV treatment markedly reduces the amount of HIV present in body fluids (eg, semen, vaginal, and anorectal secretions) and blood (as measured by HIV viral load). Fluids from persons with very low or undetectable HIV virus levels are markedly less likely to transmit HIV to uninfected persons. A study published in 2011 provided convincing evidence for the success of this preventive measure, called “treatment as prevention.” This randomized trial involved serodiscordant couples—1 partner was positive for HIV and had CD4 counts between 350 and 550 cells/mm3, whereas the other partner was HIV negative. Half of the infected partners received immediate ARV therapy, and the other half received delayed therapy based on CD4 cell count decreases or the appearance of HIV-related symptoms. Of the subsequent 28 linked transmissions, only 1 occurred in the early therapy group. Early ARV treatment resulted in both personal and public health benefits, including a dramatic and significant reduction in the rate of sexual transmission.[Cohen 2011]
Post-exposure Prophylaxis. The medical assistant in your office gave an influenza vaccination to JT, a 35-year-old male patient who came in for an urgent care visit. She reports she stuck herself with the needle after the injection.
The patient then sees you and says he is here because he had insertive and receptive rectal intercourse with a man he met at a bar 18 hours ago. He does not know if the person is HIV-positive and has no way to get in touch with him.
HIV exposure and risk of transmission
For an infectious agent found in blood, any percutaneous exposure (one that breaks the skin barrier) can potentially lead to disease transmission. [USPHS Occupational Exposure 2013] Contact with mucous membranes, which are absorptive, or non-intact skin, such as an open wound, also poses a risk. Skin forms an effective barrier against HIV transmission unless there is a portal of entry. Rough cuticles are not usually considered a portal of entry because a protective buildup of cells and tissue occurs rapidly following small breaks in the skin.