美國各州愛滋病毒新感人數的減少與暴露前預防性投藥 (PrEP

 

美國各州愛滋病毒新感人數的減少與暴露前預防性投藥 (PrEP) 的使用有關

隨著暴露前預防(PrEP)的使用持續增長,流行病學證據開始顯示PrEP攝取增加與新感染減少之間的關聯。

在阿姆斯特丹舉行的第22屆國際愛滋病大會(AIDS 2018)上發表的一項新分析顯示,在美國各州使用較高的PrEPHIV發生率降得更低之間存在相關性。

美國食品和藥物管理局(FDA)於20127月批准了舒發泰(Truvadatenofovir/emtricitabine兩種成份藥物)用於預防愛滋病毒。自那時起,PrEP的使用率穩步上升,特別是在主要城市的白人男性和雙性戀男性當中,但很難確定PrEP用戶的總人數或人口學上特徵,因為這些數據不是集中收集的。

在過去的幾年裡, Truvada的製造商 Gilead Sciences一直在根據對藥房商業上的調查報告估算PrEP的使用。在2017年國際愛滋病協會舉辦的愛滋病科學會議上,Gilead的研究人員報告說,從2012年初到2017年初,估計已有120,000人開始使用特Truvada進行暴露前預防。  Gilead隨後與埃默里大學羅林斯公共衛生學院的研究人員合作,在今年的反轉錄病毒和伺機性感染會議上報導,僅2016年就有超過77,000人接受了PrEP治療。

但是PrEP仍然只能在可能受益的人中佔一小部分。美國疾病控制和預防中心(CDC)估計,在具有實質風險感染愛滋病毒的120萬人中,只有不到10%使用PrEP

那麼PrEP使用上的增加是否導致了HIV新的感染減少了嗎?

新感的趨勢顯示情況可能確實如此。在舊金山,該市的大型同志社區在早期便採用了PrEP,新的感染率在2016年降至過去以來最低水平。但該市很早即普遍在愛滋病毒確診後立即採用抗反轉錄病毒療法,因此難以梳理出PrEP與「治療即預防」彼此間的影響。

同樣地,近期在英國倫敦進入性健康診所的男同性戀者新感人數戲劇性地下降 - 代表非常高風險之族群 以及澳洲雪梨的男男間性行為者的新感染人數之大幅下降也都歸因於多種方法,包括加強檢驗、治療和PrEP

在最新的分析報告中,Emory大學的Patrick Sullivan以及來自Gilead和疾病預防控制中心的同事們,使用自2012年至2016年中,來自美國所有50個州以及華盛頓特區13歲及以上人群的數據,研究了PrEP使用與HIV診斷率之間的相關性。 PrEP的數據使用來自於藥房而診斷的數據則來自國家愛滋病毒監測系統。

研究人員根據有可能符合接受PrEP指標者的比例將各州劃分為五等分。在最高等分中,2016年有11.0%符合條件的人使用PrEP,而最低的五等分者則為3.5%。他們指出,這些數字代表PrEP使用的最低水平,因為有些人亦從被調查之藥局外的其他來源中獲得PrEP

整體愛滋病毒新感診斷率顯著下降,從2012年的每10萬人15.7人降至2016年的每10萬人14.5人,估計每年下降率為 -1.6%。在同一時期, PrEP使用率從每1000名符合條件的人中的7.0人增加到每1000名符合條件的人中的68.5人,估計每年增加 + 78%。

但研究人員報告說,與PrEP的使用有關的一些值得注意的差異。在未經調整的分析中,PrEP使用率為五等分中最高者其愛滋病毒新感檢測率下降了 -4.7%,中高治療組的愛滋病毒診斷檢測率降低了 -0.94%。相比之下,隨著PrEP使用率為五等分位數中最低(+ 0.9%)和中低使用率者(+ 1.53%)其診斷檢測陽性率則為增加。

為了釐清PrEP與「治療即預防」的效果,研究人員還研究了來自37個州和華盛頓特區的病毒載量數據。在該項子分析中,在控制病毒抑制狀態的水平後, PrEP使用率仍然與新HIV診斷的下降顯著相關。

研究人員得出結論:「PrEP的攝取與美國HIV新感診斷率的下降顯著相關,而這種關聯與病毒抑制水平無關」。他們建議「美國各州應採取措施,增加符合使用標準者使用PrEP,並應繼續努力提升愛滋病感染者其HIV病毒量達到抑制狀態」。「透過記錄了廣泛採用舒發泰作為暴露前預防等美國各州其愛滋病毒新感病例平均數的顯著下降,我們的分析強調,在美國各州愛滋病毒篩檢可及性的改善,以及全方位包括PrEP在內的各種預防工具普及的重要性。研究者SullivanGilead公司的新聞稿當中補充道。

 

PrEP use linked to fewer new HIV infections in US states

Liz Highleyman

Published: 26 July 2018

As pre-exposure prophylaxis (PrEP) use continues to grow, epidemiological evidence is starting to show an association between increases in PrEP uptake and declines in new infections.

A new analysis presented this week at the 22nd International AIDS Conference (AIDS 2018) in Amsterdam shows a correlation between higher PrEP use and lower HIV incidence in US states.

The US Food and Drug Administration (FDA) approved Truvada (tenofovir/emtricitabine) for HIV prevention in July 2012. PrEP use has risen steadily since then, especially among white gay and bisexual men in major cities, but it has been difficult to determine the total number or demographic characteristics of PrEP users because these data are not centrally collected.

For the past several years Gilead Sciences, the maker of Truvada, has been reporting PrEP use estimates based on surveys of commercial pharmacies. At the 2017 International AIDS Society Conference on HIV Science, Gilead researchers reported that an estimated 120,000 people had ever started Truvada for PrEP from its debut in 2012 through early 2017. Gilead then teamed up with researchers at Emory University's Rollins School of Public Health, who reported at this year's Conference on Retroviruses and Opportunistic Infections that just over 77,000 people were taking PrEP in 2016 alone.

But PrEP is still only reaching a small proportion of those who might benefit. The US Centers for Disease Control and Prevention (CDC) estimates that less than 10% of the 1.2 million people at substantial risk for HIV infection are using PrEP.

So is this increase in PrEP use leading to a decrease in new HIV infections?

Trends in new infections suggest this may be the case. In San Francisco, where the city's large gay community adopted PrEP early on, new infections fell to their lowest-ever level in 2016. But the city's early adoption of universal antiretroviral therapy immediately after HIV diagnosis makes it difficult to tease out the effects of PrEP versus 'treatment as prevention'.

Likewise, a dramatic recent decline in new infections among gay men attending sexual health clinics in London – representing a very high-risk population – and a large decrease among men who have sex with men in Sydney have also been attributed to a combination of approaches including stepped up testing, treatment and PrEP.

In the latest analysis, reported as a late-breaking poster, Patrick Sullivan from Emory University and colleagues from Gilead and the CDC looked at correlations between PrEP use and HIV diagnosis rates, using data from people aged 13 and older in all 50 US states and Washington, DC, between 2012 and 2016. PrEP usage data came from pharmacies and diagnosis data from the National HIV Surveillance System.

The researchers divided the states into quintiles, or fifths, according to the proportion of people with a potential indication for PrEP who were receiving it. In the top quintile 11.0% of eligible individuals were on PrEP in 2016, compared with 3.5% in the lowest fifth. They noted that these figures represent a minimum level of PrEP use, as some people obtain PrEP from sources other than surveyed pharmacies.

The overall HIV diagnosis rate decreased significantly, from 15.7 per 100,000 persons in 2012 to 14.5 per 100,000 persons in 2016, an estimated annual decline of -1.6% per year. During the same period PrEP use increased from 7.0 per 1000 eligible people to 68.5 per 1000 eligible people, an estimated annual increase of +78%.

But some notable differences were seen in relation to PrEP use, the researchers reported. New HIV diagnoses declined by -4.7% in the quintile of states with the highest PrEP use and by -0.94% in the medium-high group in an unadjusted analysis. In contrast, diagnoses increased in the quintile with the lowest PrEP use (+0.9%) and medium-low use (+1.53%).

In an attempt to tease out the effect of PrEP versus treatment as prevention, the researchers also looked at viral load data from 37 states and DC. In this sub-analysis, the rate of PrEP use remained significantly associated with declines in new HIV diagnoses after controlling for state levels of viral suppression.

"PrEP uptake was significantly associated with declines in HIV diagnoses in the USA, and this association is independent of levels of viral suppression," the researchers concluded. They recommended that "US states should take steps to increase the use of PrEP among persons with indications and should continue efforts to increase HIV viral suppression for people living with HIV."

"By documenting significant declines in average new cases of HIV in states where Truvada for PrEP has been most widely adopted, our analysis emphasizes the importance of improving access to HIV screening and a full range of prevention tools, including PrEP, in US states," Sullivan added in a Gilead press release.

Reference

Sullivan P et al. The impact of pre-exposure prophylaxis with TDF/FTC on HIV diagnoses, 2012-2016, United States. 22nd International AIDS Conference (AIDS 2018), Amsterdam, abstract LBPEC036, 2018.