Trends in HIV incidence between 2013–2019 and association of baseline factors with subsequent incident HIV among gay,bisexual, and other men who have sex with men attending sexual health clinics in England: A prospective cohort study

BackgroundProspective cohort studies of incident HIV and associated factors among gay, bisexual, and other men who have sex with men (GBMSM) in the United Kingdom are lacking. We report time trends in and factors associated with HIV incidence between 2013 and 2019 among a cohort of GBMSM: the AURAH2 prospective study.Methods and findingsParticipants were recruited through 1 of 3 sexual health clinics in London and Brighton (July 2013 to April 2016) and self-completed a baseline paper questionnaire and subsequent 4-monthly and annual online questionnaires (March 2015 to March 2018), including information on sociodemographics, lifestyle, health and well-being, HIV status, sexual/HIV-related behaviours, and preexposure prophylaxis and postexposure prophylaxis (PrEP/PEP). Incident HIV was ascertained by linkage with national HIV surveillance data from Public Health England (PHE). We investigated the associations of HIV incidence with (1) baseline factors using mixed-effects Weibull proportional hazard models, unadjusted and adjusted for age, country of birth and ethnicity, sexuality, and education level; and (2) time-updated factors, using mixed-effects Poisson regression models.In total, 1,162 men (mean age 34 years, 82% white, 94% gay, 74% university-educated) were enrolled in the study. Thirty-three HIV seroconversions occurred over 4,618.9 person-years (PY) of follow-up: an overall HIV incidence rate (IR) of 0.71 (95% confidence interval (CI) 0.51 to 1.00) per 100 PY. Incidence declined from 1.47 (95% CI 0.48 to 4.57) per 100 PY in 2013/2014 to 0.25 (95% CI 0.08 to 0.78) per 100 PY in 2018/2019; average annual decline was 0.85-fold (p < 0.001). Baseline factors associated with HIV acquisition included the following: injection drug use (6/38 men who reported injection drug-acquired HIV; unadjusted conditional hazard ratio (HR) 27.96, 95% CI 6.99 to 111.85, p < 0.001), noninjection chemsex-related drug use (13/321; HR 6.45, 95% CI 1.84 to 22.64, p < 0.001), condomless anal sex (CLS) (26/741; HR 3.75, 95% CI 1.31 to 10·74, p = 0.014); higher number of CLS partners (HRs >10 partners [7/57]; 5 to 10 partners [5/60]; and 2 to 4 partners [11/293]: 14.04, 95% CI 4.11 to 47.98; 9.60, 95% CI 2.58 to 35.76; and 4.05, 95% CI 1.29 to 12.72, respectively, p < 0.001); CLS with HIV–positive partners (14/147; HR 6.45, 95% CI 3.15 to 13.22, p < 0.001), versatile CLS role (21/362; HR 6.35, 95% CI 2.18 to 18.51, p < 0.001), group sex (64/500; HR 8.81, 95% CI 3.07 to 25.24, p < 0.001), sex for drugs/money (4/55, HR 3.27, 95% CI 1.14 to 9.38, p = 0.027) (all in previous 3 months); previous 12-month report of a bacterial sexually transmitted infection (STI) diagnoses (21/440; HR 3.95, 95% CI 1.81 to 8.63, p < 0.001), and more than 10 new sexual partners (21/471, HRs 11 to 49, 50 to 99, and >100 new partners: 3.17, 95% CI 1.39 to 7.26; 4.40, 95% CI 1.35 to 14.29; and 4.84, 95% CI 1.05 to 22.4, respectively, p < 0.001). Results were broadly consistent for time-updated analysis (n = 622 men). The study’s main limitation is that men may not be representative of the broader GBMSM population in England.ConclusionsWe observed a substantial decline in HIV incidence from 2013 to 2019 among GBMSM attending sexual health clinics. Injection drug use, chemsex use, and measures of high-risk sexual behaviour were strongly associated with incident HIV. Progress towards zero new infections could be achieved if combination HIV prevention including Test and Treat strategies and routine commissioning of a PrEP programme continues across the UK and reaches all at-risk populations.

Nadia Hanum and colleagues analyze trends in HIV incidence among gay, bisexual, and other Men Who Have Sex with Men attending sexual health clinics in England.     

Mating compatibility and competitiveness of transgenic and wild type Aedes aegypti (L.) under contained semi-field conditions

We conducted the world??s first experiments under semi-field conditions (ACL-2 field house) to assess the mating competitiveness of genetically sterile RIDL male mosquitoes (513A strain). The field house is a state-of-the-art, fully-contained trial facility, simulating the living space for a household of 2?C4 people in Peninsular Malaysia. Ten genetically sterile RIDL male A. aegypti mosquitoes competed with ten wild type males inside this field house to mate with ten wild type females. Hatched larvae from mated females were screened under a fluorescent microscope for genetic markers to determine if they were fathered by RIDL male or wild type male, and all results were cross-checked by PCR. Two such experiments were conducted, each repeated sufficient number of times. All strains were on a Malaysian lab strain background for the first experiment, while the RIDL males alone were on a recently-colonised Mexican strain background for the second experiment. A total of 52 % of the matings were with RIDL males in the first experiment, while 45 % of the matings were with RIDL (Mexican) males in the second experiment. Statistically, this is not significantly different from 50 % of the matings expected to take place with RIDL males if the latter were as competitive as that of the wild type males. This shows that A. aegypti RIDL-513A has excellent mating competitiveness under semi-field conditions, verifying earlier trends obtained in small lab cages. We also observed high mating compatibility between recently-colonised Mexican RIDL males and lab-reared Malaysian wild type females.     

On the Use of Optically Stimulated Luminescent Dosimeter for Surface Dose Measurement during Radiotherapy

This study was carried out to investigate the suitability of using the optically stimulated luminescence dosimeter (OSLD) in measuring surface dose during radiotherapy. The water equivalent depth (WED) of the OSLD was first determined by comparing the surface dose measured using the OSLD with the percentage depth dose at the buildup region measured using a Markus ionization chamber. Surface doses were measured on a solid water phantom using the OSLD and compared against the Markus ionization chamber and Gafchromic EBT3 film measurements. The effect of incident beam angles on surface dose was also studied. The OSLD was subsequently used to measure surface dose during tangential breast radiotherapy treatments in a phantom study and in the clinical measurement of 10 patients. Surface dose to the treated breast or chest wall, and on the contralateral breast were measured. The WED of the OSLD was found to be at 0.4 mm. For surface dose measurement on a solid water phantom, the Markus ionization chamber measured 15.95% for 6 MV photon beam and 12.64% for 10 MV photon beam followed by EBT3 film (23.79% and 17.14%) and OSLD (37.77% and 25.38%). Surface dose increased with the increase of the incident beam angle. For phantom and patient breast surface dose measurement, the response of the OSLD was higher than EBT3 film. The in-vivo measurements were also compared with the treatment planning system predicted dose. The OSLD measured higher dose values compared to dose at the surface (Hp(0.0)) by a factor of 2.37 for 6 MV and 2.01 for 10 MV photon beams, respectively. The measurement of absorbed dose at the skin depth of 0.4 mm by the OSLD can still be a useful tool to assess radiation effects on the skin dermis layer. This knowledge can be used to prevent and manage potential acute skin reaction and late skin toxicity from radiotherapy treatments.     

Open Field Release of Genetically Engineered Sterile Male Aedes aegypti in Malaysia

Background

Dengue is the most important mosquito-borne viral disease. In the absence of specific drugs or vaccines, control focuses on suppressing the principal mosquito vector, Aedes aegypti, yet current methods have not proven adequate to control the disease. New methods are therefore urgently needed, for example genetics-based sterile-male-release methods. However, this requires that lab-reared, modified mosquitoes be able to survive and disperse adequately in the field.

Methodology/Principal Findings

Adult male mosquitoes were released into an uninhabited forested area of Pahang, Malaysia. Their survival and dispersal was assessed by use of a network of traps. Two strains were used, an engineered ‘genetically sterile’ (OX513A) and a wild-type laboratory strain, to give both absolute and relative data about the performance of the modified mosquitoes. The two strains had similar maximum dispersal distances (220 m), but mean distance travelled of the OX513A strain was lower (52 vs. 100 m). Life expectancy was similar (2.0 vs. 2.2 days). Recapture rates were high for both strains, possibly because of the uninhabited nature of the site.

Conclusions/Significance

After extensive contained studies and regulatory scrutiny, a field release of engineered mosquitoes was safely and successfully conducted in Malaysia. The engineered strain showed similar field longevity to an unmodified counterpart, though in this setting dispersal was reduced relative to the unmodified strain. These data are encouraging for the future testing and implementation of genetic control strategies and will help guide future field use of this and other engineered strains.