Biology subjects

Price, M. A.

Publications and source records attributed to Price, M. A..

2 recordsLinked to original sources

bioRxiv2018

Retention of adults from fishing communities in an HIV vaccine preparedness study in Masaka, Uganda

IntroductionPeople living in fishing communities around Lake Victoria may be suitable for enrolment in HIV prevention trials because of high HIV incidence. We assessed the ability to recruit and retain individuals from fishing communities into an HIV vaccine preparedness cohort study in Masaka, Uganda.\n\nMethodsHIV high risk, sero-negative adults (18-49 years) were identified from four fishing villages bordering Lake Victoria through door-to-door HIV counselling and testing (HCT). Interested persons were referred for: screening, enrolment, and quarterly follow-up visits at a study clinic located approximately 40 kilometres away. Repeat HCT, HIV risk assessment, and evaluation and treatment for sexually transmitted infections were provided. Rates of and factors associated with study dropout were assessed using Poisson regression models.\n\nResultsA total of 940 participants were screened between January 2012 and February 2015, of whom 654 were considered for the analysis. Over a two-year follow-up period, 197 (30.1%) participants dropped out of the study over 778.9 person-years, a dropout rate of 25.3 / 100 person-years. Dropout was associated with being female (aRR =1.56, 95% confidence interval [CI] 1.12-2.18), age, being 18-24 years (aRR=1.64; 95% CI 1.03-2.60), 25-34 years (aRR=1.63; 95% CI 1.04-2.55); having no education (aRR=2.02; 95% CI: 1.23-3.31); living in the community for less than one year (aRR=2.22; 95% CI: 1.46-3.38) or 1-5 years (aRR=1.68; 95% CI: 1.16-2.45) and occupation.\n\nConclusionsIt is possible to recruit and retain individuals from fishing communities, however, intensified participant tracing may be necessary in a vaccine trial to keep in follow up female, young, less educated, those in mobile occupations and new residents.

epidemiology↗

bioRxiv2017

Diagnostic, Infection Timing and Incidence Surveillance Applications of High Dynamic Range Chemiluminescent HIV Immuno-Assay Platforms

BackgroundCustom staging assays, including the Sedia HIV-1 Limiting Antigen Avidity EIA (LAg) and avidity modifications of the Ortho VITROS anti-HIV-1+2 and Abbott ARCHITECT HIV Ag/Ab Combo assays, are used to identify recent infections in clinical settings and for cross-sectional HIV incidence estimation. However, the high dynamic range of chemiluminescent platforms allows differentiating recent and longstanding infection on signal intensity, and this raises the prospect of using unmodified diagnostic assays for infection timing and surveillance applications.\n\nMethodsWe tested a panel of 2,500 well-characterised specimens with estimable duration of HIV infection with the three assays and the unmodified ARCHITECT. Regression models were used to estimate mean durations of recent infection (MDRI), context-specific false-recent rates (FRR) and correlation between signal intensity and LAg measurements. A hypothetical epidemiological scenario was constructed to evaluate utility in surveillance applications.\n\nResultsOver a range of MDRIs (reflecting recency discrimination thresholds), a diluted ARCHITECT-based RITA produced lower FRRs than the VITROS platform (FRR {approx} 0.5% and 1.5% respectively at MDRI of 200 days) and the unmodified diagnostic ARCHITECT produces incidence estimates with comparable precision to LAg (RSE {approx} 17.5% and 15% respectively at MDRI of 200 days). ARCHITECT S/CO measurements were highly correlated with LAg ODn measurements (r = 0.80) and values below 200 are strongly predictive of LAg recency and duration of infection less than one year.\n\nConclusionsLow quantitative measurements from the unmodified ARCHITECT obviate the need for additional recency testing and its use is feasible in clinical staging and incidence surveillance applications.

epidemiology↗