Management of HIV/AIDS
With the advances in antiretroviral therapy and increased life expectancy of
patients with HIV infection, the emergency physician must also consider noninfectious pathologies in the differential diagnosis.
Additionally, source patient factors have a large impact on infectivity. Due to the presence of high HIV viral load levels, the probability of transmission in the first 6 months after HIV infection has been shown to be 8- to 12-fold higher than the risk associated with exposures that take place after the viral set point. One meta-analysis concluded that the infectivity of exposures from symptomatic AIDS patients are approximately double or triple the risk of a single percutaneous exposure compared to the risk from asymptomatic patients.25
Similar to occupational exposures, many factors affect the risk of HIV acquisition from a nonoccupational exposure. With regard to sexual encounters, it is well established that the presence of other sexually transmitted infections in either partner increases transmission risk. Estimates for transmission risk between IV users range from 0.63% to 2.4%.26 Transmission risk for all types of exposures is significantly decreased when the infected person is receiving effective antiretroviral therapy.
Occupational Exposures
Some studies indicate that over 50% of EPs have reported at least one occupational exposure to HIV in a 2-year period. After an occupational exposure, if the source patient is known to be HIV-infected, information about his/her viral load, antiretroviral medication history, and history of antiretroviral drug resistance should be obtained to assist in the selection of an optimal PEP regimen. If the source’s HIV screening test result is negative, but the individual may have been exposed to HIV in the past 4 to 8 weeks, a plasma HIV RNA assay should also be obtained. If these results are not immediately available, the first dose of PEP should not be delayed.
Nonoccupational Exposures
The data are not as robust, but there is increasing evidence that nonoccupational post exposure prophylaxis (nPEP) is both effective and feasible. The Department of Health and Human Services (DHHS) recommends the prompt initiation of nPEP HAART when persons seek care within 72 hours after exposure, the source is known to be HIV infected, and the exposure event presents a substantial risk for transmission. When the HIV status of the source is not known and the patient seeks care within 72 hours after exposure, the DHHS does not recommend for or against nPEP but encourages clinicians and patients to weigh the risks and benefits on a case-by-case basis. When the transmission risk is negligible or when patients seek care >72 hours after a substantial exposure, nPEP is not recommended except on a case-by-case basis at the discretion of the clinician.27,28
Pre-exposure Prophylaxis
Pre-exposure prophylaxis, or PrEP, is a way for people who do not have HIV but who are at substantial risk of getting it to prevent HIV infection by taking an antiretroviral every day. Taking tenofivir or tenofivir plus emtricitabine (Truvada) daily has been shown to reduce by up to 92% the risk of acquiring HIV in heterosexual couples with one HIV-infected partner and by men who have sex with men (MSM).29-31 A 2013 study provided the first evidence that PreP amongst injection drug users offers substantial protection against HIV acquisition.29-32
On May 14, 2014, the USPHS released the first comprehensive clinical practice guidelines for PrEP, which include recommendations for daily fixed-dose combination of tenofovir and emtricitabine in people who engage in high risk sexual behaviors and for injection drug users. There is also a new tenofovir-eluting intravaginal ring that offered complete protection in a macaque monkey model of simian-HIV acquisition.33 The human version of this intravaginal ring is currently undergoing phase I clinical trials in the United States and Kenya.
Conclusion
Even though great strides have been made in the education, prevention, and treatment of HIV/AIDS, it continues to be a major public health issue in the United States. As the life expectancy of individuals with an HIV-positive status has increased, these patients may present to the ED not only with symptoms related to HIV infection, but also with symptoms associated with nonrelated conditions, including adverse effects of HAART and other comorbidities. In addition, EPs should also have a high index of suspicion for HIV infection in previously undiagnosed patients presenting with symptoms associated with seroconversion syndrome—the early diagnosis of which will provide earlier recognition and treatment.
Dr Battistich is an assistant professor of emergency medicine, department of emergency medicine, New York University School of Medicine. She completed a fellowship in Global Health and International Emergency Medicine at Yale University.
