美國研究發現,年輕黑人同性戀伴侶之間的同意、權力和年齡差異對

美國研究發現,年輕黑人同性戀伴侶之間的同意、權力和年齡差異對HIV傳播的影響可能大於個人特徵

暴露前預防(PrEP)建議用於「困難的性情況」中的保護

Gus Cairns/ 2019927/aidsmap news/財團法人台灣紅絲帶基金會編譯

對德克薩斯州休斯頓和達拉斯兩個城市的年輕黑人同性戀和雙性戀男性進行的一項相當大的調查發現,同性戀者之間的權力動態可能是愛滋病毒透過黑人同性戀社區繼續傳播的最重要影響,而不是處於不利地位的個人,例如青年、貧困或低學歷。

這項研究使用了一種稱為「潛在特徵分析」的技術,該技術研究了傾向於在被調查人群中聚集在一起的特徵。它將這些特徵群集與愛滋病毒風險相關聯。透過這種方式,它可以生成具有特定程度風險去感染或傳播愛滋病毒之人群的「特性」(本研究對愛滋病毒陽性和陰性的男性均進行了調查)。

它向參與者提出了兩種不同類型的問題。一組是關於社會人口學上的年齡、收入、教育程度以及被監禁和無家可歸的歷史等標準問題。

另一組則著眼於男人的信念和人際關係。它詢問他們在多大程度上同意他們在其關係中有能力維持安全的性行為、使用保險套容易或困難、是否接受愛滋病毒治療會降低人們的傳染性、是否同意對愛滋病毒感染者的污名仍然很嚴重,及以類推的問題。

本單元中的典型問題包括:

•「暫停下來去戴保險套會破壞性情緒多少?」

•「如果與您發生性關係的男人開始做不安全的事情,您阻止他有多難?」

•「與無法檢測到病毒載量的HIV陽性男子於沒有戴套的情況下進行肛交是否安全?」

•「大多數人對愛滋病毒感染者感到不舒服」。

他們還問了一些很重要的問題,即所謂的「艱難的性處境和性關係」。在這些情況下,人們想要做的事情和感到壓力被迫要做的事情之間存在衝突。關於困難的性處境有九個問題,關於困難的人際關係有四個問題。提出的13個問題中全部都涉及去年:

•「通常您多久會感到孤獨和沮喪並藉由性來獲得疏解?」

•「您或您的伴侶在性愛過程中處於藥嗨狀態的情形多久會發生一次?」

•「因害怕失去某人而與某人發生性關係的的情形多久會發生一次?」

•「您與在性行為過程中會要求您信任他們的人多久會發生性關係?」

結果

1,808名平均年齡為25歲的男子在各種同性戀場域(從酒吧到公園)被招募,受訪者因其付出時間而有30美元回報。其中七分之一(14.4%)的人說自己感染了愛滋病毒。受訪者的收入和教育程度有廣大的範圍:雖有24%的人年收入低於10,000美元,但亦有相同比例的人年收入超過40,000美元,而有12%的人收入超過60,000美元。有 15%的人未能完成高中畢業,但亦有21%是大學畢業生。

21%的人為失業者和有13%的人說他們去年至少有一次把錢全用光了,但相對有較少的人曾入獄(2.6%)或是無家可歸者(0.23%)。

在整個群體中,這些年輕人對他們可以保持更安全的性生活之信念相對較高,並有中等水平的愛滋病毒恥辱感。他們總體上認為保險套易於使用。

但是,他們對“ U = U”(無法檢測到病毒等於不會造成傳播)以及病毒被抑制降低了傳播風險的事實有明顯低水準之認知。作者對此感到擔憂。他們評論說:「儘管過去發現愛滋病毒治療上的樂觀與性風險行為有關,但卻普遍缺乏對愛滋病毒治療高度的樂觀……而如果目標是要讓感染者參與治療,顯示這可能是一個需要去針對的重要因素,...以實現病毒被抑制」。

但是,大多數的研究著重於社會人口學因素、經驗和信念的聚集。本研究之人員發現,研究對象傾向於集體分為四個具特徵性「特性」危險因素的集團。

需要注意的一件重要的事是,這些特性完全獨立於人們的實際之HIV狀況。愛滋病毒呈陽性的人可以屬於任何特性的人。潛在特徵分析僅查看特定因素是否趨向於聚集,而不是看它們是否與特定結果相關。

•一半的人口聚集在低風險人群中。這些男人往往是愛滋病毒陰性且受過良好教育。他們對可以保持更安全性行為上有很高的信念,對保險套的消極態度也相應較低。與其他人群相比,他們對愛滋病毒恥辱的擔心要小一些。有趣的是,他們是最不可能同意U = U訊息的群體。

•四分之一的受訪者可歸為中等風險。愛滋病毒陽性的男性比其他任何男性都更有可能出現在這一個群體中。他們對自己可以保持更安全性行為的信念水平較低,對保險套的負面態度是低風險人群中男性的兩倍。他們某種程度上更有可能相信U = U訊息,並且在處境艱難的性生活中的可能性是具低風險特色人群的兩倍。平均而言,他們比其他特色群體的男性要年輕一些,這是一個年齡本身唯一與其他特色集團男人有所不同的族群。

•只有5%的男性聚集在研究人員認為屬於高風險人群中。這些男人也比一般平均更容易感染愛滋病毒,並且是唯一真正更有可能遭受貧困的人群。他們對安全性行為的信心最低,對保險套的懷疑程度最高。他們更有可能受到關注帶有愛滋病毒的污名–但是比其他人更了解U = U。真正脫穎而出的是,他們發現自己處於困難的性環境中的可能性是低風險組的三倍,幾乎是其他任何組的兩倍。鑑於該人群對保險套持消極態度的可能性是低風險人群的三倍,研究人員評論說:「PrEP對於那些不使用保險套或其他任何形式的安全性行為或沒有足夠的意識能力來談判更安全的性行為等等的人可能是理想的方法」。

•然而,真正令研究人員感興趣的是剩下的20%的男性,他們形成了他們所謂的「混合型態」。他們相信自己能夠保持更安全的性行為和使用保險套的能力與低危人群中的男人一樣高,並且在同意U = U聲明上相一致。儘管他們有自己的信念,但是他們更加擔心愛滋病毒的污名。他們舉報困難性行為狀態是接近於低風險人群的兩倍,但在過去一年中,發生這種情況則是超過低風險人群的兩倍。在後一種情況下,他們發生困難的性關係的可能性比高風險組僅低18%。儘管年齡無法預測每個男人屬於那一特色集團,但年齡較小且愛滋病毒呈陽性的男人更可能屬於混合型。

「處於艱難的性關係中」是各特色集團間差異最大的因素,也是界定那一個特性在反映較高或較低的風險程度上最強的特徵。

「對於一些年輕男男性行為者的黑人來說,讓他們感到沒有辦法且喪失權力的性愛情境和關係可能是適當介入措施的目標。」

這些發現意味著什麼?他們隱涵著,個人社會人口學上的因素,至少在接受調查的年輕同性戀黑人中,在HIV風險預測上可能不如個人的信念、態度和經驗來得重要。

他們更暗示,一個特別重要的族群可能是年輕人,他們的愛滋病毒風險高於社會人口學因素所預期的水平,他們可能會面臨到在自己想做的事情上、甚至自己認為可以做的事情上,因受到其他男人的壓力而被迫採取了不同行動之間所產生的衝突。。

研究人員評論說,鑑於這一特性的人佔了調查人口的20%,而且四倍大於具高風險特徵者,因此他們可能會對美國同性戀黑人社區中持續的HIV發生率造成不成比例的影響。

作者評論說:「這種結果的形式顯示,對於一些與男人發生性關係的年輕黑人,讓他們感受到自己沒有能力之喪失權力的性處境和關係-特別是如果決策是受到物質影響的話-可能是介入措施上更合適的目標,亦比個人保險套的使用和態度來得更重要。」

有趣的是,愛滋病毒呈陽性的年輕男同性戀者更有可能具有較高的風險,因為他們倆都可能更敏銳地感覺到自己有被排斥的風險,並且在與年長的男人發生關係中保持性行為安全方面較缺乏能力。研究人員評論說:「有限的性愛網絡可能會導致困難的性愛情況」。換句話說,您感覺到的潛在的伴侶越少,您就越有可能妥協:乞求者無法成為選擇者

這項研究中的一個有趣發現是,儘管有兩組其愛滋病毒的風險明顯最高,但似乎也是對治療即預防(U = U)的了解水準最高的族群,並且由他們對保險套的態度可能表明他們會對暴露前預防(PrEP)感興趣。因此,就有機會扭轉風險–只要持續努力的工作能使年輕人放心,他們被迫採取違反自我信念和更佳判斷的情況並不總是他們的錯。

 

Consent, power and age difference between young black gay couples may have more effect on HIV transmission than individual characteristics, US study finds

PrEP recommended for protection in “difficult sexual situations”

Gus Cairns / 27 September 2019 / aidsmap news

A quite large survey of young black gay and bisexual men in two Texan cities, Houston and Dallas, has found that power dynamics between gay couples may be the most important influence on the onward spread of HIV through the black gay community, rather than factors that disadvantage individuals such as youth, poverty or low education.

The study used a technique called 'Latent Profile Analysis' which looks at characteristics that tend to cluster together among a surveyed population. It related these clusters of characteristics to HIV risk. In this way it was able to generate 'profiles' of the kind of people who had particular degrees of risk of either acquiring or transmitting HIV (it surveyed both HIV-positive and HIV-negative men).

It asked two different types of questions of its participants. One set were the standard demographic questions, about age, income, education and histories of imprisonment and homelessness.

The other set looked at the men’s beliefs and relationships. It asked them to what degree they agreed that they were capable of maintaining safer sex in their relationships, that condoms were easy or difficult to use, whether HIV treatment reduced people’s infectiousness, whether they agreed that stigma against people with HIV was still severe, and so on.

Typical questions in this section included, for instance:

·        “How much does pausing to put on a condom ruin the sexual mood?”

·        “If a man you are having sex with starts to do something unsafe, how difficult is it for you to stop him?”

·        "It is safe to have anal sex without a condom with an HIV-positive man who has an undetectable viral load?”

·        "Most people are uncomfortable around someone with HIV”.

They also asked questions, which turned out to be important, about what they called “difficult sexual situations and relationships”. These tended to be situations where there was a conflict between what people wanted to do, and what they felt pressure to do. There were nine questions about difficult sexual situations, and four about difficult relationships. Among the 13 questions asked were (all concerning the last year):

·        “How often have you been lonely and depressed and had sex to feel good?”

·        “How often have you had sex where you or your partner was high on drugs?”

·        “How often have you had sex with someone because you were afraid of losing them?”

·        “How often have you been in a sexual situation with someone who asked you to trust them?”

Results

The 1808 men had an average age of 25, and were recruited at a variety of gay-frequented venues ranging from bars to parks, with respondents paid $30 for their time. One in seven (14.4%) said they had HIV. There was a wide range of both income and education in the group: while 24% earned less than $10,000 a year, the same proportion earned over $40,000 and 12% over $60,000. Fifteen per cent had failed to finish high school, but 21% were college graduates.

Twenty-one per cent were unemployed and 13% said they had run out of money at least once last year, but relatively small numbers had ever been in prison (2.6%) or homeless (0.23%).

Over the group as a whole, these young men had relatively high levels of belief they could maintain safer sex and moderate levels of perceived HIV stigma. They thought on the whole that condoms were easy to use.

However, they had remarkably low levels of awareness of 'U=U' (Undetectable equals Untransmittable) and the fact that viral suppression reduces infection risk. The authors are concerned about this. They comment, “Although HIV treatment optimism has been found to be associated with sexual risk behavior in the past, the general lack of high HIV treatment optimism…suggests that it may be an important factor to target if the goal is to engage men living with HIV…to achieve viral suppression.”

Most of the study, however, is concerned with the clustering of demographic factors, experiences and beliefs. The researchers found that the study population tended to group into four characteristic “profiles” of clusters of risk factors.

One important thing to note is that these profiles were quite independent of people’s actual HIV status. HIV-positive people could belong to any profile. Latent profile analysis simply looks at whether particular factors tend to congregate, rather than whether they are related to a particular outcome.

·        Half the population clustered into a low-risk profile. These men tended to be HIV negative and relatively well educated. They had high levels of belief they could maintain safer sex and correspondingly low negative attitudes to condoms. They were less worried about HIV stigma than other groups. Interestingly, they were the group least likely to agree with U=U messages.

·        A quarter of the respondents clustered into a medium-risk profile. HIV-positive men were more likely to be in this group than any other. They had rather lower levels of belief that they could maintain safer sex, and were twice as likely to have negative attitudes towards condoms than men in the low-risk profile. They were somewhat more likely to believe in U=U messages and were nearly twice as likely to have been in difficult sexual situations than men in the low-risk profile. They were slightly younger, on average, than men in other profiles – the only one where age, in itself, made a difference.

·        Just 5% of the men clustered into what the researchers considered to be the high-risk profile. These men were also more likely than average to have HIV and were the only group really significantly more likely to experience poverty. They had the lowest levels of confidence about safer sex and the highest levels of condom scepticism. They were somewhat more likely to be concerned with HIV stigma – but were a lot more aware than others about U=U. What really stood out was that they were three times more likely than the low risk group, and nearly twice as likely as any other group, to have found themselves in difficult sexual situations. Given that this group were three times more likely to have negative attitudes towards condoms than the low-risk group, the researchers comment that “PrEP may be an ideal approach for those who do not use condoms or another form of safer sex, or who have insufficient sense of agency to negotiate safer sex.”

·        The cluster that really interested the researchers, though, were the remaining 20% of men, who formed what they called a “mixed profile”. Their belief in their ability to maintain safer sex and condom use was as high as men in the low-risk profile, as was their agreement with U=U statements. They were, however, somewhat more concerned about HIV stigma – and despite their self-beliefs, they were nearly twice as likely as the low-risk group to report difficult sexual situations, over the last year, and more than twice as likely to have been in difficult sexual relationships. In the latter case, they were only 18% less likely than the high-risk group to have experienced difficult sexual relationships. Although age did not predict which profile individual men belonged to, men who were younger and HIV positive were more likely to belong to the mixed profile.

“Having been in difficult sexual relationships” was the factor that varied most between profiles, and so was the feature that most strongly defined the degree to which a profile reflected higher or lower risk.

"For some young black MSM, disempowering sexual situations and relationships in which they feel they lack agency may be appropriate targets of intervention.”

What do these findings signify? They imply that individual socioeconomic factors, as least in the young gay black men surveyed, may be less important predictors of HIV risk than individual beliefs, attitudes and experiences.

They additionally imply that a particularly important group, with HIV risk higher than would have been predicted from socioeconomic factors, may be young men who experience conflict between what they want to do, and even believe they can do, and the pressures to act otherwise from other men.

The researchers comment that, given that this profile made up 20% of the population surveyed and was therefore four times bigger than the high-risk profile, they might contribute disproportionately to ongoing HIV incidence in the US gay black community.

“This pattern of results,” comment the writers, “indicates that for some young black men who have sex with men, disempowering sexual situations and relationships in which they feel they lack agency – especially if decisions are affected by substances – may be more appropriate targets of intervention than individual condom use or attitudes.”

It is interesting that HIV-positive, younger gay men are more likely to have higher-risk profiles, as they may both feel more keenly that they are at risk of rejection, and that they have less agency when it comes to maintaining sexual safety with older men. “Limited sexual networks may contribute to difficult sexual situations,” comment the researchers. In other words, the fewer potential partners you feel are available, the more likely you are to compromise: beggars can’t be choosers.

One interesting finding in this study is that the two groups with the highest apparent risk of HIV nonetheless appeared to be those with the highest levels of knowledge about treatment as prevention (U=U) and whose attitudes to condoms may suggest that they would be interested in PrEP. There are thus opportunities to turn risk around – as long as work is done to reassure young men that situations in which they are pressured into acting against their own self-beliefs and better judgements are not always their fault.

References

Vincent W et al. A person-centered approach to HIV-related protective and risk factors for young black men who have sex with men: implications for pre-exposure prophylaxis and HIV treatment as prevention. AIDS and Behavior, early online publication, 2019. https://doi.org/10.1007/s10461-019-02630-5