愛滋病毒的終結在美國
資料來源：刺胳針感染症醫學期刊，財團法人台灣紅絲帶基金會編譯www.thelancet.com/infection Vol 19 April 2019
美國承諾透過「治療即預防」(treatment as prevention)和「暴露前預防投藥」(PrEP)來消除其愛滋病毒之流行；但是仍存在著重大的結構性挑戰。 Talha Burki報導。
美國總統川普在2019年2月5日他的國情咨文演講中，提出了雄心勃勃的承諾。「科學的突破已經讓一個過去曾經遙不可及的夢想變成觸手可及」，他開始說道。「我將要求民主黨和共和黨提供致力於消除愛滋病毒在美國流行所需的預算」。「衛生福利部（HHS）隨後概述了計劃，它設想於5年內減少75％的愛滋病毒新感個案和 10年內達到減少90％。而2017年在全美國則共有38,281例愛滋病毒新感個案被診斷。
美國有超過3000多個縣。但在2016年和2017年則有超過一半的愛滋新感案例集中在包括華盛頓特區、波多黎各和聖胡安在內的48個縣內。除此之外，七個南方州還特別有高度的農村型愛滋病負擔。這些縣、市和州將是該項結束疫情計畫的最初重點。資金將分配於2019-20會計年度中的預算，並從十月開始。這些奠基於科學的和臨床基礎上致力於消除上的努力，則是「治療即預防」和「暴露前預防投藥」（PrEP）。其目的是部署這些工具讓他們能夠在最佳的地方做的最好。
該計劃依賴於四大支柱：診斷、治療、保護和回應。在美國有23％的愛滋病毒感染者是由那些不知道自己的感染狀態的人所傳播，亦即是在全美110萬感染者當中佔人口統計學上15％的人所傳播。擴大檢驗和診斷的範圍將是疾病控制和預防中心（CDC）的責任。該機構預計在即將到來的會計年度中會有實質性的資金注入。
Ryan White HIV / AIDS計畫（RWHAP），提供美國低收入的愛滋病毒感染者治療上的協助，接受計畫者其病毒已經被抑制之比率為86％，而全國平均則為60％。在美國有超過三分之二感染者，其愛滋病毒感染係經由已被診斷但卻不在醫療體系中治療的個案傳播所導致。 RWHAP在針對關鍵族群之成果改善上已取得了顯著之成功，如跨性別者、青少年（在2017年有五分之一的新感個案是集中在那些年齡層為13-24歲的人當中）以及居無定所的人。 衛生福利部部長Alex Azar承諾「讓計畫中全面性的照護和治療系統發揮功能，以提升全國各地病毒被抑制的比例達到90％」。負責執行RWHAP的衛生資源和服務管理局，已被承諾將增加資金，不僅加速透過RWHAP來提供治療且加速暴露前預防投藥的擴散。
疾病控制和預防中心估計全美有110萬人面臨著感染愛滋病毒的極大風險，且應該提供暴露前預防投藥。該藥物目前只有達到這些人當中的不到10％，但是消除計畫希望提升這個比例至少達到50％。計畫也打算迅速解決到處萌芽之愛滋病毒突發流行。國家衛生研究院將監督執行之科學情況、整理數據和評估各種方法。在短期內它不會收到任何額外的資金，但是在下一會計年度將期望會帶來可觀的挹注。
在歐巴馬政府時期擔任白宮國家愛滋病政策辦公室資深顧問並共同撰寫2010年全國愛滋病策略的Gregorio Millett表示「在很多方面，我將新的計畫視為一種自然進展」。「以風險群體為重點並在可創造最大影響的領域上擴大介入措施；在幾年前我們就真的建立在我們所實施的地方上了」。「有鑑於阿片類藥物疫情的惡化，針對靜脈注射藥癮者的減害計畫之支持一直在增加。但是，要讓資源到達市郊和農村的社區，則形成後勤上的挑戰；導致減害服務往往侷限在城市。有三分之二的美國人是居住在與針具和注射器交換點至少10英里外的地方。
針對切斷愛滋病毒新感方法的有效性已被許多城市的經驗證實，諸如舊金山和紐約。「我們有實證上之證據，如果你跨出去並為所有需要治療的人提供治療，並讓那些處於感染風險之中的人能有效獲得PrEP的藥物，則你將可以實現偉大的事情」，Chris Beyrer（美國馬里蘭州巴爾的摩約翰霍普金斯大學）解釋道。「所以毫無疑問，我們可以達到消除愛滋的境界，但它需要在對應愛滋病毒最具影響的許多地方上做一個龐大方式的改變」。
目前仍有許多實質上的結構障礙；在美國大約70％的愛滋新感染個案是男男間性行為者。 44％的新感個案發生在非裔美國人社區，儘管他們只佔全人口的13％。 一半的新感發生在南部的州，但只有少於三分之一的美國人是生活在此區域中。在2010年平價醫療法案強制要求擴大低收入戶醫療補助計畫(Medicaid)，但許多南方州都拒絕加入計畫。「當我們真正需要以一個更全面廣泛性的方式去取得醫療照顧時，特別是在針對工作貧困階級者（指的是擁有固定工作但相對貧窮，例如收入低於特定貧窮線的人士）時，需要關心的一個問題是，我們可能會退縮回到以垂直的方式去對應愛滋之流行」
Beyrer補充道。
污名仍然是一個巨大的問題。 Beyrer強調說：「對於在阿肯色州、奧克拉荷馬州或密西西比州的一名黑人來說，走進一家公共診所並說他與很多男人發生性關係且他需要PrEP來解決問題非常困難」。在這種情況下，社區參與是必不可少的。「愛滋的控制只有在社區參與並具有領導角色之作用時才有效」，Beyrer說。性行為動態上的變化會使外展變得更加困難棘手，目前年輕人傾向於在網路上尋找伴侶。 「我們將必需用創新技術和虛擬方法來吸引人們」，Beyrer說。
據估計，美國每年有14％的愛滋病毒感染者涉及刑事司法系統。他們在從監獄釋放後通常會面臨治療中斷，並且很快就會變成病毒血症。黑人男性不成比例的被監禁率可能有助於解釋，為什麼非洲裔美國婦女儘管性行為風險低，但愛滋病毒的感染率卻很高。「我們需要重新回歸治療的計畫，以便他們一旦重回到社區時，就能讓他們穩定地保持在治療中」，Millett說。 「一段時間以來，這些計畫的規模未見擴增一直是一個長期存在的問題」。
儘管存在這些挑戰，但Millett對消除美國愛滋流行的前景仍抱持審慎樂觀的態度。他指出，該計畫無需在各個地方均立即取得成功，「我們只需要在概念上驗證，這種方法可以在某一個地方能夠實際運作；如果這種情況發生了，那麼政策制定者和倡議者就會問為什麼不能把它帶到其他的地方，而當這種情況發生時，它就真的會打開了閘門」。
The end of HIV in the USA
www.thelancet.com/infection Vol 19 April 2019
The USA has pledged to eliminate its HIV epidemic through treatment-as-prevention and pre-exposure prophylaxis. But there are substantial structural challenges. Talha Burki reports.
In his State of the Union address on Feb 5, 2019, Donald Trump offered an ambitious promise. “Scientific breakthroughs have brought a oncedistant dream within reach”, he began. “My budget will ask Democrats and Republicans to make the needed commitment to eliminate the HIV epidemic in the United States.” The plan was subsequently outlined by the Department of Health and Human Services (HHS). It envisages a reduction in new HIV infections by 75% within 5 years and 90% within 10 years. The USA saw 38 281 diagnoses of HIV in 2017.
The USA has more than 3000 counties. But over half the new cases of HIV in 2016 and 2017 occurred
in 48 counties, including Washington DC and San Juan, Puerto Rico. In addition, seven southern states have
notably high rural burdens of HIV. These counties, cities, and states will be the initial focus of the plan to end the epidemic. Funding will be assigned in the budget for the 2019–20 fiscal year, which begins in October. The scientific and clinical basis of the elimination effort will be treatment-as-prevention and pre-exposure prophylaxis (PrEP).The intention is to deploy these tools where they are likely to do the most good.
The plan rests on four pillars: diagnosis, treatment, protection, and response. 23% of HIV infections in the USA are transmitted by individuals who are unaware of their status, a demographic thought to account for 15% of 1·1 million or so Americans who carry the virus. Expanding access to testing and diagnosis will be the responsibility of the Centres for Disease Control and Prevention (CDC).The agency expects a substantial injection of funds in the forthcoming fiscal year.
The Ryan White HIV/AIDS Programme (RWHAP), which offers assistance to low-income Americans infected with HIV, has achieved viral suppression rates of 86%. The national average is 60%. More than two-thirds of Americans who contract HIV do so from individuals who have been diagnosed but are not in care. RWHAP has had marked success in improving outcomes for key populations, such as transgender individuals, youngsters (one-fifth of new infections in 2017 were among those aged 13–24 years), and people with unstable housing. HHS Secretary Alex Azar has pledged “to leverage the programme’s comprehensive system of care and treatment to increase viral suppression around the country to 90%”. The Health Resources and Services Administration, which runs the RWHAP, has been promised additional funding, both to accelerate provision of treatment through RWHAP and to distribute PrEP.
The CDC estimates that 1·1 million Americans are at substantial risk of contracting HIV and should be offered PrEP. The drug is currently reaching fewer than 10% of these people, but the elimination plan hopes to raise this proportion to at least 50%. It also intends to rapidly tackle burgeoning HIV outbreaks. The National Institutes of Health will oversee the implementation science, collating data and assessing the
various approaches. It will not receive any additional money in the short-term, but there is the expectation that the next fiscal year will bring a substantial boost.
Gregorio Millett was senior adviser in the White House Office of National AIDS Policy in the Obama administration and co-wrote the 2010 National AIDS Strategy. “In many ways, I see the new plan as a natural progression”, he said. “There is the focus on risk groups as well as scaling up interventions in
areas where they can make the biggest impact; that really builds on what we put in place years ago.” Support for harm-reduction programmes for injecting drug users has been increasing in light of the worsening opioid epidemic. However, reaching suburban and rural communities provides logistical challenges; harm-reduction services tend to be in the cities. Twothirds of Americans live at least 10 miles from a needle and syringe exchange.
The effectiveness of targeted approaches in cutting new HIV infections has been borne out by the experiences of cities, such as San Francisco and New York. “We have empirical evidence that if you get out and provide treatment to those in need and get good uptake with PrEP for those at risk, you can achieve great things”, explains Chris Beyrer (Johns Hopkins University, Baltimore, MD, USA). “So there is no doubt that we can get to elimination, but it is going to take an enormous change in the way the most affected places are addressing HIV.” There are substantial structural barriers. Around 70% of new HIV infections in the USA are among men who have sex with men. 44% of new infections occur in the African-American community, even though they only represent 13% of the population. Half of new infections occur in the southern states, yet few more than a third of Americans live in this region. The 2010 Affordable Care Act mandated an expansion of Medicaid, but several southern states have refused to participate. “One concern is that we may be returning to a vertical approach to address the HIV epidemic, when what we really need is a much more comprehensive approach to access to care, particularly among the working poor”, adds Beyrer.
Stigma remains a huge issue. “It is very tough for a black man in Arkansas, Oklahoma, or Mississippi to walk into a public clinic and say that he is having sex with lots of men and he needs PrEP—that needs to be addressed”, stresses Beyrer. In which case, community engagement is indispensable. “HIV control only works when the community is involved and has leadership roles”, said Beyrer.
In which case, community engagement is indispensable. “HIV control only works when the community is involved and has leadership roles”, said Beyrer. Changing sexual dynamics make outreach trickier, now that young people tend to find partners online. “We are going to have to use innovative technology and virtual approaches to reach people”, said Beyrer.
An estimated 14% of people living with HIV in the USA have some involvement with the criminal justice system every year. They typically face treatment interruptions after they are released from prison and can very quickly become viraemic. The disproportionate rates of incarceration for black men might help explain why African-American women, despite their low sexual risk profile, have high rates of HIV. “We need re-entry programmes to keep people stable on treatment as soon as they re-enter the community”, said Millett. “The lack of scale-up of these programmes has been a persistent problem for some time”.
Despite these challenges, Millett is cautiously optimistic about the prospects for eliminating the HIV epidemic in the USA. He points out that the plan does not have to show immediate success everywhere. “We just need proof-of-concept that this approach can work in one place; if that happens, then policy-makers and advocates are going to ask why it cannot be brought to other places, and when that happens, it will really open the floodgates.”