A ship-based methodology for high precision atmospheric oxygen measurements and its application in the Southern Ocean region

A method for achieving continuous high precision measurements of atmospheric O-2 is presented based on a commercially available fuel-cell instrument, (Sable Systems, Oxzilla FC-II) with a precision of 7 per meg (approximately equivalent to 1.2 ppm) for a 6-min measurement. The Oxzilla was deployed on two voyages in the Western Pacific sector of the Southern Ocean, in February 2003 and in April 2004, making these the second set of continuous O-2 measurements ever made from a ship. The results show significant temporal variation in O-2, in the order of +/- 10 per meg over 6-hourly time intervals, and substantial spatial variation. Data from both voyages show an O-2 maximum centred on 50 degrees S, which is most likely to be the result of biologically driven O-2 outgassing in the region of subtropical convergence around New Zealand, and a decreasing O-2 trend towards Antarctica. O-2 from the ship-based measurements is elevated compared with measurements from the Scripps Institution of Oceanography flask-sampling network, and the O-2 maximum is also not captured in the network observations. This preliminary study shows that ship-based continuous measurements are a valuable addition to current fixed site sampling programmes for the understanding of ocean-atmosphere O-2 exchange processes. [References: 39

Understanding experiences of potential harm among MSM (cis and trans) using HIV self-testing in the SELPHI randomised controlled trial in England and Wales: a mixed-methods study

Background: The potential of HIV self-testing (HIVST) to cause harm is a concern hindering widespread implementation. The aim of this paper is to understand the relationship between HIVST and harm in SELPHI (An HIV Self-testing Public Health Intervention), the largest randomised trial of HIVST in a high-income country to date. Methods: 10 111 cis and trans men who have sex with men (MSM) recruited online (geolocation social/sexual networking apps, social media), aged 16+, reporting previous anal intercourse and resident in England or Wales were first randomised 60/40 to baseline HIVST (baseline testing, BT) or not (no baseline testing, nBT) (randomisation A). BT participants reporting negative baseline test, sexual risk at 3 months and interest in further HIVST were randomised to three-monthly HIVST (repeat testing, RT) or not (no repeat testing, nRT) (randomisation B). All received an exit survey collecting data on harms (to relationships, well-being, false results or being pressured/persuaded to test). Nine participants reporting harm were interviewed in-depth about their experiences in an exploratory substudy; qualitative data were analysed narratively. Results Baseline: predominantly cis MSM, 90% white, 88% gay, 47% university educated and 7% current/former pre-exposure prophylaxis (PrEP) users. Final survey response rate was: nBT=26% (1056/4062), BT=45% (1674/3741), nRT=41% (471/1147), RT=50% (581/1161). Harms were rare and reported by 4% (n=138/3691) in exit surveys, with an additional two false positive results captured in other study surveys. 1% reported harm to relationships and to well-being in BT, nRT and RT combined. In all arms combined, being pressured or persuaded to test was reported by 1% (n=54/3678) and false positive results in 0.7% (n=34/4665). Qualitative analysis revealed harms arose from the kit itself (technological harms), the intervention (intervention harms) or from the social context of the participant (socially emergent harms). Intervention and socially emergent harms did not reduce HIVST acceptability, whereas technological harms did. Discussion: HIVST harms were rare but strategies to link individuals experiencing harms with psychosocial support should be considered for HIVST scale-up

Comparing the effects of HIV self-testing to standard HIV testing for key populations: a systematic review and meta-analysis.

BACKGROUND: We update a previous systematic review to inform new World Health Organization HIV self-testing (HIVST) recommendations. We compared the effects of HIVST to standard HIV testing services to understand which service delivery models are effective for key populations. METHODS: We did a systematic review of randomised controlled trials (RCTs) which compared HIVST to standard HIV testing in key populations, published from 1 January 2006 to 4 June 2019 in PubMed, Embase, Global Index Medicus, Social Policy and Practice, PsycINFO, Health Management Information Consortium, EBSCO CINAHL Plus, Cochrane Library and Web of Science. We extracted study characteristic and outcome data and conducted risk of bias assessments using the Cochrane ROB tool version 1. Random effects meta-analyses were conducted, and pooled effect estimates were assessed along with other evidence characteristics to determine the overall strength of the evidence using GRADE methodology. RESULTS: After screening 5909 titles and abstracts, we identified 10 RCTs which reported on testing outcomes. These included 9679 participants, of whom 5486 were men who have sex with men (MSM), 72 were trans people and 4121 were female sex workers. Service delivery models included facility-based, online/mail and peer distribution. Support components were highly diverse and ranged from helplines to training and supervision. HIVST increased testing uptake by 1.45 times (RR=1.45 95% CI 1.20, 1.75). For MSM and small numbers of trans people, HIVST increased the mean number of HIV tests by 2.56 over follow-up (mean difference = 2.56; 95% CI 1.24, 3.88). There was no difference between HIVST and SoC in regard to positivity among tested overall (RR = 0.91; 95% CI 0.73, 1.15); in sensitivity analysis of positivity among randomised HIVST identified significantly more HIV infections among MSM and trans people (RR = 2.21; 95% CI 1.20, 4.08) and in online/mail distribution systems (RR = 2.21; 95% CI 1.14, 4.32). Yield of positive results in FSW was not significantly different between HIVST and SoC. HIVST reduced linkage to care by 17% compared to SoC overall (RR = 0.83; 95% CI 0.74, 0.92). Impacts on STI testing were mixed; two RCTs showed no decreases in STI testing while one showed significantly lower STI testing in the intervention arm. There were no negative impacts on condom use (RR = 0.95; 95% CI 0.83, 1.08), and social harm was very rare. CONCLUSIONS: HIVST is safe and increases testing uptake and frequency as well as yield of positive results for MSM and trans people without negative effects on linkage to HIV care, STI testing, condom use or social harm. Testing uptake was increased for FSW, yield of positive results were not and linkage to HIV care was worse. Strategies to improve linkage to care outcomes for both groups are crucial for effective roll-out

Protocol, rationale and design of SELPHI: A randomised controlled trial assessing whether offering free HIV self-testing kits via the internet increases the rate of HIV diagnosis 11 Medical and Health Sciences 1117 Public Health and Health Services 11 Medical and Health Sciences 1103 Clinical Sciences

BACKGROUND: Among men who have sex with men (MSM) in the UK, an estimated 28% have never tested for HIV and only 27% of those at higher risk test at least every 6 months. HIV self-testing (HIVST), where the person takes their own blood/saliva sample and processes it themselves, offers the opportunity to remove many structural and social barriers to testing. Although several randomised controlled trials are assessing the impact of providing HIVST on rates of HIV testing, none are addressing whether this results in increased rates of HIV diagnoses that link to clinical care. Linking to care is the critical outcome because it is the only way to access antiretroviral treatment (ART). We describe here the design of a large, internet-based randomised controlled trial of HIVST, called SELPHI, which aims to inform this key question. METHODS/DESIGN: The SELPHI study, which is ongoing is promoted via social networking website and app advertising, and aims to enroll HIV negative men, trans men and trans women, aged over 16 years, who are living in England and Wales. Apart from the physical delivery of the test kits, all trial processes, including recruitment, take place online. In a two-stage randomisation, participants are first randomised (3:2) to receive a free baseline HIVST or no free baseline HIVST. At 3 months, participants allocated to receive a baseline HIVST (and meeting further eligibility criteria) are subsequently randomised (1:1) to receive the offer of regular (every 3 months) free HIVST, with testing reminders, versus no such offer. The primary outcome from both randomisations is a laboratory-confirmed HIV diagnosis, ascertained via linkage to a national HIV surveillance database. DISCUSSION: SELPHI will provide the first reliable evidence on whether offering free HIVST via the internet increases rates of confirmed HIV diagnoses and linkage to clinical care. The two randomisations reflect the dual objectives of detecting prevalent infections (possibly long-standing) and the more rapid diagnosis of incident HIV infections. It is anticipated that the results of SELPHI will inform future access to HIV self-testing provision in the UK. TRIAL REGISTRATION: DOI 10.1186/ISRCTN20312003 registered 24/10/2016

Understanding experiences of potential harm among MSM (cis and trans) using HIV self-testing in the SELPHI randomised controlled trial in England and Wales: a mixed-methods study.

BACKGROUND: The potential of HIV self-testing (HIVST) to cause harm is a concern hindering widespread implementation. The aim of this paper is to understand the relationship between HIVST and harm in SELPHI (An HIV Self-testing Public Health Intervention), the largest randomised trial of HIVST in a high-income country to date. METHODS: 10 111 cis and trans men who have sex with men (MSM) recruited online (geolocation social/sexual networking apps, social media), aged 16+, reporting previous anal intercourse and resident in England or Wales were first randomised 60/40 to baseline HIVST (baseline testing, BT) or not (no baseline testing, nBT) (randomisation A). BT participants reporting negative baseline test, sexual risk at 3 months and interest in further HIVST were randomised to three-monthly HIVST (repeat testing, RT) or not (no repeat testing, nRT) (randomisation B). All received an exit survey collecting data on harms (to relationships, well-being, false results or being pressured/persuaded to test). Nine participants reporting harm were interviewed in-depth about their experiences in an exploratory substudy; qualitative data were analysed narratively. RESULTS: Baseline: predominantly cis MSM, 90% white, 88% gay, 47% university educated and 7% current/former pre-exposure prophylaxis (PrEP) users. Final survey response rate was: nBT=26% (1056/4062), BT=45% (1674/3741), nRT=41% (471/1147), RT=50% (581/1161).Harms were rare and reported by 4% (n=138/3691) in exit surveys, with an additional two false positive results captured in other study surveys. 1% reported harm to relationships and to well-being in BT, nRT and RT combined. In all arms combined, being pressured or persuaded to test was reported by 1% (n=54/3678) and false positive results in 0.7% (n=34/4665).Qualitative analysis revealed harms arose from the kit itself (technological harms), the intervention (intervention harms) or from the social context of the participant (socially emergent harms). Intervention and socially emergent harms did not reduce HIVST acceptability, whereas technological harms did. DISCUSSION: HIVST harms were rare but strategies to link individuals experiencing harms with psychosocial support should be considered for HIVST scale-up. TRIAL REGISTRATION NUMBER: ISRCTN20312003

Impact and acceptability of HIV self-testing for trans men and trans women: A mixed-methods subgroup analysis of the SELPHI randomised controlled trial and process evaluation in England and Wales.

BACKGROUND: Globally, trans people are disproportionately affected by HIV, but research on strategies to increase testing are limited. SELPHI is a randomised-controlled-trial (RCT) of 10,135 cis men, trans men, and trans women reporting lifetime anal intercourse with male partners (cis or trans), evaluating whether the offer of free HIV self-testing (HIVST) increases diagnosis. This subgroup analysis from the SELPHI RCT aims to describe key HIVST outcomes and HIVST acceptability for trans people. METHODS: SELPHI recruited using social networking and trans focused social media. Participants were randomised 60/40 to baseline HIVST (Biosure™) (BT) vs no baseline HIVST (nBT); and at 3-months (if completed the survey and reported recent CAI) 50/50 to 3-monthly HIVST (RT) vs no repeat HIVST (nRT). Outcomes were self-reported through online surveys. We conducted a qualitative study of semi-structured peer-led participant interviews (n = 20) exploring HIVST motivations and experiences. These were analysed using a framework approach. FINDINGS: SELPHI recruited and randomised 118 trans men and trans women (94 trans men, 24 trans women), of whom 20 (16 trans men, 4 trans women) underwent the second randomisation. Median age at baseline was 29 (IQR: 22, 37), 79% were white, 79% were UK born, 37% had degree level education, and 31% had never tested for HIV. 62% (n = 59) of trans men completed the 3-month survey, but survey completion by trans women in nBT was too low (1/11) for randomised comparison. In trans men HIV testing uptake by 3 months was significantly higher in BT (95% 36/38) vs nBT (29%, 6/21) (RR=3.32 (1.68, 6.55) p<0.001). Trans people randomised to RT reported 3 times higher rate of HIV testing compared to nRT during the two-year follow-up (IRR 3.66 (1.86, 8.01) p<0.0001). STI testing frequency (mean number of tests during each 13 week period/ 2-year follow-up) was not significantly different across interventions: RT (0.03) and nRT (0.01) (IRR=1.86 95%CI; 0.77, 5.15; p = 0.15). Social harms were rare. Acceptability was very high in BT: 97% (38/39) found instructions easy to understand, 97% (37/38) found the HIVST simple to use and 100% (39/39) reported good overall experience. In interviews, reported HIVST benefits included increased autonomy, privacy, convenience and avoidance of health care providers perceived to be discriminatory and services that increased dysphoria. Minor lancet and test processing issues were reported. INTERPRETATION: HIVST significantly increased testing uptake and frequency in trans men and trans people overall, although recruitment and retention of trans women was low. HIVST acceptability was high and indicates easy access to this novel technology may increase HIV testing access for this key population

Pilot phase of an internet-based RCT of HIVST targeting MSM and transgender people in England and Wales: advertising strategies and acceptability of the intervention

BACKGROUND: The SELPHI study (An HIV Self-Testing Public Health Intervention) is an online randomised controlled trial (RCT) of HIV self-testing (HIVST). The aim of this study was to assess the feasibility of recruiting UK men who have sex with men (cis and trans) and trans women who have sex with men to the SELPHI pilot, and the acceptability of the HIVST intervention used among those randomised to receive a kit. METHODS: A mixed-methods approach to assessing trial feasibility and intervention acceptability was taken, using quantitative data from advertising sources and RCT surveys alongside qualitative data from a nested sub-study. RESULTS: Online recruitment and intervention delivery was feasible. The recruitment strategy led to the registration of 1370 participants of whom 76% (1035) successfully enrolled and were randomised 60/40 to baseline testing vs no baseline testing. Advertising platforms performed variably. Reported HIVST kit use increased from 83% at two weeks to 96% at three months. Acceptability was very high across all quantitative measures. Participants described the instructions as easy to use, and the testing process as simple. The support structures in SELPHI were felt to be adequate. Described emotional responses to HIVST varied. CONCLUSIONS: Recruiting to a modest sized HIVST pilot RCT is feasible, and the recruitment, intervention and HIVST kit were acceptable. Research on support needs of individuals with reactive results is warranted

HIV Testing and HIV Serostatus-Specific Sexual Risk Behaviour Among Men Who Have Sex with Men Living in England and Recruited Through the Internet in 2001 and 2008.

Using data from two large internet-recruited surveys in England in 2001 and 2008, we examine HIV status-specific patterns of unprotected anal intercourse (UAI). In adjusted comparisons between our 2008 and 2001 samples, there was evidence of a greater proportion of men living with diagnosed HIV, a reduction in sexual partners and in UAI with partners of unknown HIV status among men not tested HIV positive, increases in anal intercourse and UAI among men with diagnosed HIV and an increase in insertive UAI with HIV-positive men among men never tested for HIV. However, we found no evidence for increases in negotiated safety or sero-sorting. The data are compatible with a concentration of sexual risk among men with diagnosed HIV, countering an overall trend towards less risk taking among men not tested HIV positive