HIV Prevention Knowledge Base
Biomedical Interventions: Post-exposure Prophylaxis (PEP)
Nonoccupational HIV Post-exposure Prophylaxis: A 10-year Retrospective Analysis
This retrospective study, conducted in Switzerland, is the largest account of the precipitating circumstances, clinical procedures, and outcomes associated with NPEP of HIV. Of 1068 referrals for PEP, 910 eligible records were identified for the study: 734 reported sexual exposures and 179 reported nonsexual exposures, the latter were primarily users of illicit drugs who were sharing drug injecting equipment. The sample is unusual because the large majority of exposures were heterosexual (77 percent). Research reported in the literature focuses on MSM or assault victims. Following established Swiss national guidelines, if the HIV status of the source person or object is unknown or uncertain, an attempt to find the source and determine and confirm status is made. In 72 percent of the cases, the source was not known. However, 298 sources (42 percent) were found and 178 tested negative, thereby reducing the number of unnecessary PEP treatments in 31 percent of the group (n = 283). An additional 11 individuals from high-risk groups were found to be living with HIV. Of the 710 people who initiated PEP, 423 completed treatment, 108 discontinued when the source was determined to be HIV-negative, 39 dropped out because they could not tolerate the drug regimen, and a high number of 117 people (16 percent) were lost to follow-up. The researchers conclude that tracking and testing the source for the exposure is not only good clinical practice, but also cost-effective.
Postexposure Prophylaxis for HIV Infection
Although evidence of the efficacy of PEP for HIV has not been established in clinical trials due to cost and ethical issues, guidelines have emerged from a host of smaller studies that provide reliable parameters for when exposure indicates treatment for different exposure types (occupational and nonoccupational) and cases that have the highest risk for transmission. Elapsed time from exposure to treatment (no more than 48 hours), the duration of treatment (4 weeks), risks and benefits associated with different drug combinations, and requisite adherence to regimens are considered in turn. Useful tables on two- and three-drug combinations and laboratory tests recommended for persons exposed and treated are also included. The authors conclude that although PEP is considered to be effective when certain conditions are met, ultimately, it is the degree of risk aversion on the part of the doctor and the patient that will dictate whether PEP is initiated and completed.
Occupational and Nonoccupational Postexposure Prophylaxis for HIV in 2009
This article reviews treatment protocols and new studies on combination drug regimens for HIV PEP. Guidance on elapsed times from exposure to initiation of treatment in nonoccupational cases, a critical variable in success, ranges from 36 (U.S. state of New York) to 72 hours (CDC, WHO, and others). The rationale for the differences is discussed. The author also includes useful tables with doses and common side effects of the most commonly used two-drug regimen (e.g., 3TC/ZDV) and more recent ones (TDF/FTC) as compared to triple combinations (e.g., 3TC/ZDV plus IDV or NFV). Two-drugs are better tolerated, although three-drugs are indicated when significant ARV drug resistance or high-risk exposure has been identified. Patients referred for PEP must be assessed for transmission risk (minimal to moderate). A collateral benefit of providing PEP to patients is that, in the author’s view, it can be used as a valuable educational moment, an opportunity to discuss behavioral risks and suggest referrals for additional screening and counseling.
Post-exposure Prophylaxis (PEP) to Prevent HIV Infection: Guidelines on the Use of Treatment Starter Kits
This document provides explicit procedures that are to be adopted in any type of PEP for HIV experienced by U.N. personnel or family members who work and live in regions where medical treatment may not be immediately available. Starter kits with five days worth of a three-drug combination ARV for PEP, in addition to emergency contraception for possible pregnancy, are made available to team leaders. Rationale for the steps to be followed and information for local doctors or medical staff who may be unfamiliar with PEP are also given.
Engendering Health Sector Responses to Sexual Violence and HIV in Kenya: Results of a Qualitative Study
Societal norms underlie sexual violence perpetrated on women, but these attitudes are poorly understood and rarely discussed in African countries. To inform HIV prevention programs being set up for victims of sexual abuse in three districts in Kenya, researchers conducted 16 focus groups and 34 key informant interviews with adult and adolescent men and women, counselors, members of the police, religious organizations, and legal advocates. Results reveal that what people think constitutes consensual and coerced sex, both within and outside marriage, is ambiguous. Both men and women said that women and girls who say “no” to sex do not necessarily mean it. Counselors and police said they felt unprepared to discuss rape and provide adequate support to victims of sexual violence. In addition, there was very little awareness of the availability of PEP, what it entailed, and its value in preventing HIV. The researchers recommend that community outreach about PEP and gender training for heath sector staff and others who interact with rape victims should be integral components of prevention and treatment programs.
Delivering Post-rape Care Services: Kenya's Experience in Developing Integrated Services
Offering integrated services for rape victims that include PEP is difficult everywhere in the world but presents significant challenges in resource-limited settings. This article describes the process used in three districts in Kenya to initiate a comprehensive sexual assault and PEP program. Based on two waves of formative research, the district health management teams, in collaboration with a Kenyan nongovernmental organization, trained personnel in hospital or clinic emergency units. The teams developed, and providers successfully used, an algorithm that detailed triage and standards of care for a full range of services for victims (clinical exam, PEP eligibility and treatment, test for HIV status, trauma counseling, emergency contraception, treatment of sexually transmitted infection, legal support, and post-treatment testing). The program provided PEP to 84 percent of the 784 rape victims referred for treatment in the three districts between 2003 and 2007. The estimated per patient cost for services (PEP, labs, and staff) was $27. The authors believe that the model can be replicated in other resource-poor locales, and provide recommendations and lessons learned based on their experience.
Post-exposure Prophylaxis for HIV Infection After Sexual Assault: When is It Indicated?
Determining whether to offer emergency PEP to victims of sexual violence requires doctors to rapidly assess multiple factors. The effectiveness of NPEP is not known because clinical trials have not been conducted; therefore, decisions to offer PEP treatment must be made by judging the evidence for each case individually. The author presents a three-step decision tree for assessing who should receive PEP. The three factors are the following: 1) the actual or likely HIV status of the perpetrator (if known or determinable); 2) the probable risk that the assault would lead to HIV; and 3) considerations that affect treatment effectiveness (e.g., time elapsed since the attack, trauma, likelihood of completing treatment, special needs groups such as pregnant women and children). Despite the issues outlined, the author concludes that even when the risk of transmission is small, offering victims of assault PEP may well be justifiable.
HIV PEP Guidelines After Sexual Assault
These guidelines for PEP, revised in April 2010, describe three levels of risk for HIV based on the type of perpetrator (e.g., HIV-positive, MSM), extent of injury and/or type of assault (e.g., vaginal, rectal, oral), and elapsed time since the event. Considered together, the three indicators are used to determine likelihood of transmission and the type of PEP treatment (none, basic, or expanded) that would be recommended. Useful case management guidance and additional guidance on determining PEP eligibility is also given in the appendix, which details five case examples of sexual assault and risk.
HIV Post-Exposure Prophylaxis in an Urban Population of Female Sex Workers in Nairobi, Kenya
Post-exposure prophylaxis (PEP) is a potential HIV prevention strategy among high-risk groups such as sex workers (SWs). The study examined how PEP was used, its adherence levels, and HIV incidence among SWs in Nairobi, Kenya. Non-infected participants were selected from among those who were enrolled in a prevention and care program for sex workers from 2008 to 2010. Eleven percent (n = 326) of SWs requested PEP after it was offered in 2009. Those who did not use PEP were a natural control group (n = 2,570). PEP users received risk reduction counseling, HIV counseling and testing, Combivir twice a day for 28 days, emergency contraception, and sexually transmitted infection prophylaxis. A physical exam and blood work were given to all those who requested PEP as well as a questionnaire to document demographic, behavior, and PEP use information. It was found that there were no HIV seroconversions among the PEP users while 2.2 percent of non-users seroconverted. PEP users were found to be in sex work for a shorter amount of time, less likely to have a regular partner, more likely to use a condom 100 percent of the time with causal clients, and more likely to be tested for HIV prior to the study compared to non-users. Most requests for PEP came after sex with a first time causal client (69.2 percent). The most common reasons for seeking PEP were not trusting the client and not knowing the client’s HIV status. It is recommended that PEP use be within the first twenty-four hours after exposure, and the median time from possible exposure to HIV and PEP use was 18 hours. However, one-fourth of the SWs initiated PEP after thirty-six hours, which is longer than recommended. Fifty-six percent returned to the clinic for their final PEP dose; therefore, adherence needs to be improved. The authors recommend that guidelines for PEP use need to be developed for this population.
Adherence to HIV Post-Exposure Prophylaxis in Victims of Sexual Assault: A Systematic Review and Meta-Analysis
The review and meta-analysis explored post-exposure prophylaxis (PEP) access rates and levels of adherence among adults and children after they were sexually assaulted in both developed and developing countries. All observational and experimental studies that addressed the topic of PEP adherence among sexual assault victims were included in the analysis. The authors reviewed data on the study’s characteristics, indicators on the quality of the studies, and outcome data. They also distinguished between those who were adherent to the PEP regimen, those who refused PEP treatment, and those who defaulted on the regimen. Twenty-four studies met the inclusion criteria. The studies included both adults and children, and about half were from sexual assault services. Eight of the studies were conducted in developing countries. The majority of studies did not report how adherence was measured, and the studies varied on the PEP regimens that were prescribed. There was a wide range of reported adherence in the cohort studies, from about 12 percent to 74 percent. The pooled proportion was about 40 percent, and this figure was somewhat higher compared to what was found in the randomized controlled trial. Adherence in developing countries was higher than in developed countries. For defaulters in the cohort studies, the range was from about 3 percent to 76 percent, with the pooled proportion at about 41 percent. In the cohort studies, the pooled proportion of clients who refused PEP was about 29 percent, and about one-third did not complete the full PEP regimen. In conclusion, there is a need to standardize PEP treatment among sexual assault victims as well as to increase activities and research to improve adherence.