Barreiro Pablo
Carlos III-La Paz University Hospital, Madrid, Spain.
AIDS Rev. 2018 Jan-Mar;20(1):71.
Pre-exposure prophylaxis (PrEP) with oral Truvada (tenofovir plus emtricitabine) is effective at preventing HIV infection in high-risk homosexual men. In the United States, PrEP was approved in 2012 and is reimbursed by Medicaid and the majority of private insurers. The situation is diverse and not uniform in the European Union, being PrEP more widely used in France than in the rest of countries. Concerns have been raised that PrEP use may be accompanied by the phenomena of risk compensation or behavioral disinhibition, whereby PrEP users' perception of decreased risk of HIV acquisition may lead them to engage in overall riskier sexual practices and increase their chances of acquiring sexually transmitted infections (STIs) (Blumenthal, et al. Virtual Mentor. 2014;16:909-15). Modifiable factors that may influence the acquisition of STI include condom use, number of partners, partner characteristics, and healthcare-seeking behaviors. In addition, MSM may alter HIV risk mitigation practices while on PrEP by decreasing seroadaptive practices such as serosorting that is seeking a partner of similar perceived serostatus (Khosopour, et al. AIDS Behav. 2017;21:2935-44). High rates of STI have been reported among PrEP users, as well as high rates of condomless sex, and increasing rates of STI over time (Liu, et al. JAMA Intern Med. 2016;176:75-84; Kojima, et al. AIDS, 2016;30:2251-2). In a new study conducted in Montreal, Canada, increases in the rates of STI in PrEP users were demonstrated measuring incidence rates of STI before and following the initiation of PrEP in the same cohort. The authors measured the incidence of gonorrhea, chlamydia, and/or syphilis in 109 HIV-seronegative homosexual men 12 months before and 12 months after beginning Truvada for HIV prevention (Nguyen, et al. AIDS. 2018;32:523-30). New episodes of gonorrhea, chlamydia, and/or syphilis rose in the cohort after providing Truvada, as shown in Figure 1. Moreover, the incidence of three or more STI increased from 3.7 to 9.2 cases per 100 personyears in this cohort. The Canadian study highlighted that the rate of STI with PrEP was also higher than in a group of 86 homosexual men that had undergone PEP in Montreal during 2010-2015. Other findings of the study we the high rate of STI with anorectal location, symptomless STI (e.g., chlamydia) and the frequency of sex partners contacted by internet. The increased rates of STI in PrEP users suggest a need to reinforce counseling and STI diagnosis and treatment efforts. Although PrEP may provide a public health benefit beyond the immediate prevention of HIV infection as result of bringing into care high-risk homosexual men who might not otherwise be seeking care for STI, doctors in charge must take this opportunity for informing adequately on STI and the risks inherent to multiple and occasional sexual contacts.
口服特鲁瓦达（替诺福韦加恩曲他滨）进行暴露前预防（PrEP）可有效预防高危同性恋男性感染艾滋病毒。在美国，PrEP于2012年获得批准，医疗补助计划和大多数私人保险公司都给予报销。在欧盟，情况各不相同且不统一，PrEP在法国的使用比其他国家更为广泛。有人担心，使用PrEP可能会伴随着风险补偿或行为抑制现象，即PrEP使用者认为感染艾滋病毒的风险降低，这可能会导致他们采取总体风险更高的性行为，并增加感染性传播感染（STIs）的几率（布卢门撒尔等人，《虚拟导师》，2014年；16:909 - 15）。可能影响性传播感染感染的可改变因素包括使用避孕套、性伴侣数量、伴侣特征以及就医行为。此外，男男性行为者在服用PrEP期间可能会改变艾滋病毒风险降低措施，减少血清适应性行为，如血清分型（即寻找具有相似血清状态感知的伴侣）（霍索普尔等人，《艾滋病行为》，2017年；21:2935 - 44）。据报道，PrEP使用者中性传播感染的发生率很高，无保护性行为的发生率也很高，而且随着时间推移性传播感染的发生率不断上升（刘等人，《美国医学会内科杂志》，2016年；176:75 - 84；小岛等人，《艾滋病》，2016年；30:2251 - 2）。在加拿大蒙特利尔进行的一项新研究中，通过测量同一队列中开始使用PrEP之前和之后的性传播感染发病率，证实了PrEP使用者中性传播感染发生率的增加。作者测量了109名艾滋病毒血清阴性的同性恋男性在开始服用特鲁瓦达进行艾滋病毒预防前12个月和后12个月的淋病、衣原体和/或梅毒发病率（阮等人，《艾滋病》，2018年；32:523 - 30）。如图1所示，在提供特鲁瓦达后，该队列中淋病、衣原体和/或梅毒的新发病例有所增加。此外，该队列中三种或更多种性传播感染的发病率从每100人年3.7例增加到了9.2例。加拿大的这项研究强调，PrEP使用者的性传播感染发生率也高于2010 - 2015年期间在蒙特利尔接受暴露后预防（PEP）的86名同性恋男性群体。该研究的其他发现包括肛门部位性传播感染的高发生率、无症状性传播感染（如衣原体）以及通过互联网联系性伴侣的频率。PrEP使用者中性传播感染发生率的增加表明需要加强咨询以及性传播感染的诊断和治疗工作。尽管PrEP可能会带来公共卫生益处，因为它能让那些可能不会因性传播感染而寻求治疗的高危同性恋男性接受治疗，从而直接预防艾滋病毒感染，但负责的医生必须利用这个机会充分告知性传播感染以及多次和偶尔性接触所固有的风险。
