BACKGROUNDThe global goal to end the AIDS epidemic cannot be achieved without estimates of incidence and undiagnosed infection.AIMWe aimed to estimate the timing of HIV transmission events and the number of people unaware of their diagnosis in Scotland, by mode of acquisition and migrant status.METHODSSurveillance data from Scotland's national HIV diagnosis database (1981-2022) linked to death and migration data was entered into the HIV Platform tool of the European Centre for Disease Prevention and Control, to back-calculate HIV incidence while imputing missing data and adjusting for reporting delay.RESULTSWe estimated 8,235 HIV transmission events between 1980 and 2022 among people living in Scotland, with an 80% reduction from 2010 to 2021 (258 to 52 events). Excluding people diagnosed outside Scotland, we estimated 4,854 (95% confidence interval (CI): 4,637-5,080) people living with HIV at the end of 2021, of whom 8.2% (396/4,854) were undiagnosed. Stratified estimates of this proportion were 6.9% for gay, bisexual and other men who have sex with men, 7.0% for people who inject drugs, 12.6% and 12.4% for heterosexuals born and not-born in the United Kingdom (UK), respectively. Including people first diagnosed with HIV outside Scotland, the overall proportion undiagnosed was 6.1% (396/6,444).CONCLUSIONScotland is on track to meet the United Nations' diagnosis target of 95% by 2025, with the World Health Organization target of a 75% incidence reduction met since 2010. To reduce further transmission, expanded HIV testing and prevention services are necessary to better reach at-risk heterosexual individuals.

Supplemental Digital Content is Available in the Text. Background:To inform global ambitions to end AIDS, evaluation of progress toward HIV incidence reduction requires robust methods to measure incidence. Although HIV diagnosis date in routine HIV/AIDS surveillance systems are often used as a surrogate marker for incidence, it can be misleading if acquisition of transmission occurred years before testing. Other information present in data such as antibody testing dates, avidity testing result, and CD4 counts can assist, but the degree of missing data is often prohibitive.Methods:We constructed a Bayesian statistical model to estimate the annual proportion of first ever HIV diagnoses in Scotland (period 2015-2019) that represent recent HIV infection (ie, occurring within the previous 3-4 months) and incident HIV infection (ie, infection within the previous 12 months), by synthesizing avidity testing results and surveillance data on the interval since last negative HIV test.Results:Over the 5-year analysis period, the model-estimated proportion of incident infection was 43.9% (95% CI: 40.9 to 47.0), and the proportion of recent HIV infection was 21.6% (95% CI: 19.1 to 24.1). Among the mode of HIV acquisition categories, the highest proportion of recent infection was estimated for people who inject drugs: 27.4% (95% CI: 20.4 to 34.4).Conclusions:The Bayesian approach is appropriate for the high prevalence of missing data that can occur in routine surveillance data sets. The proposed model will aid countries in improving their understanding of the number of people who have recently acquired their infection, which is needed to progress toward the goal of HIV transmission elimination.

: Recent improvements to HIV care at the NHS Lothian Board have concentrated on a re-mapping of the processes involved in their existing Integrated Care Pathway (ICP), in order to incorporate improvements identi-fied during the ICP implementation and consider new advances in care. Our work aims to extend and enhance this mapping by formalising care workflows using our logic-based tool WorkflowFM. This paper presents our progress to date in terms of methodology and initial findings concerning actors, resources and workflows involved in the first 3 months of HIV care for the Chalmers Sexual Health Centre. We argue that the resulting models and analysis could address some of the difficulties faced by units providing HIV outpatient care.

We describe ongoing work on the modelling, verification, and implementation of Integrated Care Pathways (ICPs) for HIV patients in Scotland. Healthcare knowledge, including existing policies, guidelines, and best practices, is encoded in formal, process-based, workflow models. This is achieved through the use of our logic-based, modelling framework WorkflowFM , which provides high levels of rigour and trust about the designed ICPs. We believe this effort will result in a formally verified, easily maintainable, computer based implementation of HIV ICPs that will greatly improve the current standard of care.

Condom use problems are common amongst Scotland’s men who have sex with men (MSM). To date condom errors have been associated with the likelihood of sexually transmitted infections in heterosexual sexually transmitted infection (STI) clinic attendees but not in MSM and direct evidence of a link between condom problems and STI acquisition in MSM have been lacking. This study investigated the possibility of an independent association between condom proficiency, condom problems and STI acquisition in MSM in Scotland.

Epstein-Barr virus is present in the saliva of most persistently infected individuals and is generally thought to be spread by close oral contact. However, there are now several reports of EBV in genital secretions, suggesting the possibility of sexual transmission between adults. The present study was undertaken to investigate the risk of sexual transmission of EBV. PCR analysis was used to examined the degree to which a group (n = 11) of patients with infectious mononucleosis (IM) shared the same viral isolates as their sexual partners, and compare this to the extent of isolate sharing among a different group (n = 18) of IM patients and their non-sexual contacts. There was significantly more sharing of EBV isolates among the IM/sexual-contact pairs than among the IM/non-sexual-contact pairs (P = 0.0012). Female cervical (n = 84), male urethral (n = 55), and semen (n = 30) samples from asymptomatic, unselected volunteers were analyzed for the presence of EBV DNA, revealing 7%, 5%, and 3% to be EBV positive, respectively. Fractionation of cervical and urethral samples into cellular and supernatant fluid components showed EBV to be mainly cell-associated. Quantitation of EBV in these samples gave levels of below 10 EBV genomes per microg of DNA. Overall the findings support the possibility that EBV could on occasions be transmitted sexually, however, the low levels detected in genital secretions compared to saliva suggest that this is not a major transmission route. The finding of small quantities of cell-associated virus suggests a latent infection; thus EBV is probably in the B lymphocyte rather than in the epithelial cell component of the secretions.