Publications

BACKGROUND

Safe and effective use of pre-exposure prophylaxis (PrEP) depends on retention in care after initial engagement.

SETTING

The United States PrEP Demonstration Project offered daily oral tenofovir/emtricitabine to participants in San Francisco, Miami, and Washington, D.C. for 48 weeks from 2012-2014.

METHODS

Demo Project participants' patterns of retention were assigned to one of three categories: early loss to follow-up (ELTF) within the first 12 weeks of the study, retention throughout the study, or intermittent retention in which missed or delayed visits resulted in gaps in medication availability. For each group, baseline characteristics were tabulated. A two-step multivariable analysis was performed.

RESULTS

Overall, 366/554 (66.1%) of enrolled participants were retained for all study visits, 127/554 (22.9%) had intermittent retention, and 61/554 (11.0%) early loss to follow-up (ELTF). In multivariable analysis Miami compared to San Francisco site was associated with ELTF rather than full retention (aOR 2.84; CI:1.24-6.47) and also with intermittent rather than full retention (aOR 2.70; CI:1.43-5.11). Younger age was associated with ELTF (aOR 1.80 for each 10-year decrement in age; CI:1.26-2.57) and intermittent retention (aOR 1.47; CI:1.17-1.84) compared with full retention. Factors associated with ELTF (but not intermittent retention) compared with full retention, were black race compared with white (aOR 3.32; CI:1.09-10.16), reported sex work (aOR 4.67; CI 1.49-14.58), lack of regular employment (aOR 2.53; CI: 1.27-5.05), and lack of prior PrEP awareness (aOR 2.01; CI:1.01 -3.96).

CONCLUSION

Tailored interventions addressing causes and risk factors for loss from PrEP care may improve retention and consistency of PrEP use.

is a model genus that is of particular interest for understanding apomixis due to the presence of numerous apomictic diploid lineages that are tightly correlated with hybridisation events. includes many narrowly distributed endemics and apomictic hybrid lineages that obscure morphological boundaries amongst taxa. In this study, we focus on the complex, a phylogenetically well-supported but taxonomically complex north-western United States clade whose diploid species currently include the widespread and two narrowly distributed serpentine endemics, and . Using a 15-locus microsatellite dataset, we infer ploidy and sexual vs. apomictic reproduction for all individuals and then assess species limits for all sexual diploid samples. Our results support the recognition of and as distinct species and reveal three divergent sexual diploid lineages within sensu lato. The latter three lineages exhibit geographic, genetic and morphological coherence and consequently warrant recognition at the species rank. These include s.s., which is restricted to Idaho and eastern Oregon, , a newly described species distributed along the Cascade Mountain Province from Lassen County, California north to Deschutes County, Oregon and the heretofore dismissed species (basionym ≡ ), which occurs along the Sierra Nevada Province from Plumas County southwards to Fresno County, California. Our data also reveal substructure in that is likely attributable to the highly fragmented distribution of its serpentine habitat. This refined taxonomic framework for the complex enhances as a model system, adds to our knowledge of speciation in edaphically extreme environments and provides information on ongoing conservation efforts for these taxa.