Microorganisms oxidize glucose through distinct pathways in permeable and cohesive sediments.

In marine sediments, microbial degradation of organic matter under anoxic conditions is generally thought to proceed through fermentation to volatile fatty acids, which are then oxidized to CO2 coupled to the reduction of terminal electron acceptors (e.g. nitrate, iron, manganese, and sulfate). It has been suggested that, in environments with a highly variable oxygen regime, fermentation mediated by facultative anaerobic bacteria (uncoupled to external terminal electron acceptors) becomes the dominant process. Here, we present the first direct evidence for this fermentation using a novel differentially labeled glucose isotopologue assay that distinguishes between CO2 produced from respiration and fermentation. Using this approach, we measured the relative contribution of respiration and fermentation of glucose in a range of permeable (sandy) and cohesive (muddy) sediments, as well as four bacterial isolates. Under anoxia, microbial communities adapted to high-energy sandy or bioturbated sites mediate fermentation via the Embden-Meyerhof-Parnas pathway, in a manner uncoupled from anaerobic respiration. Prolonged anoxic incubation suggests that this uncoupling lasts up to 160 h. In contrast, microbial communities in anoxic muddy sediments (smaller median grain size) generally completely oxidized 13C glucose to 13CO2, consistent with the classical redox cascade model. We also unexpectedly observed that fermentation occurred under oxic conditions in permeable sediments. These observations were further confirmed using pure cultures of four bacteria isolated from permeable sediments. Our results suggest that microbial communities adapted to variable oxygen regimes metabolize glucose (and likely other organic molecules) through fermentation uncoupled to respiration during transient anoxic conditions.

The Effect of Adolescent Idiopathic Scoliosis on Natural Delivery and Epidural Use in Pregnant Females: A Matched Cohort Study.

STUDY DESIGN: Retrospective matched cohort study. OBJECTIVE: The aim of this study was to determine whether females with idiopathic scoliosis (IS), both with and without spine fusion, experience different rates of cesarean section (CS) and epidural anesthesia (EA) than females without scoliosis. SUMMARY OF BACKGROUND DATA: IS is a common spine condition with a higher prevalence in females. It is unclear whether females with scoliosis, treated nonoperatively or operatively, have different rates of cesarean delivery or EA. MATERIALS AND METHODS: Patients with IS who delivered in our integrated health care system during a 6-year period were identified (N = 1810). They were matched with a group without scoliosis who delivered during the same period (N = 1810). Rates and relative risk (RR) of CS and EA between cohorts and subgroups were calculated. RESULTS: The scoliosis cohort had significantly higher rates and RR of EA ( P = 0.002 and P = 0.004, respectively). Scoliosis patients treated nonoperatively had an 8% greater RR of EA ( P = 0.004) and had a significantly lower rate of CS (23.2% vs . 26%, P = 0.048) compared with the control group. Among only scoliosis patients, those treated with spine fusion had a 38% decreased RR of EA ( P < 0.001). Distal fusion level did not seem to influence the RR of EA or CS. CONCLUSIONS: Females with scoliosis were significantly more likely to receive EA at delivery compared with females without scoliosis. Rates and RR of cesarean delivery were not significantly lower among women with scoliosis, but females treated nonoperatively for scoliosis had a significantly lower CS rate than those without scoliosis. Females treated with spine fusion for scoliosis were far less likely to receive EA than both females without scoliosis and females with scoliosis treated nonoperatively.

Molecular hydrogen in seawater supports growth of diverse marine bacteria.

Molecular hydrogen (H2) is an abundant and readily accessible energy source in marine systems, but it remains unknown whether marine microbial communities consume this gas. Here we use a suite of approaches to show that marine bacteria consume H2 to support growth. Genes for H2-uptake hydrogenases are prevalent in global ocean metagenomes, highly expressed in metatranscriptomes and found across eight bacterial phyla. Capacity for H2 oxidation increases with depth and decreases with oxygen concentration, suggesting that H2 is important in environments with low primary production. Biogeochemical measurements of tropical, temperate and subantarctic waters, and axenic cultures show that marine microbes consume H2 supplied at environmentally relevant concentrations, yielding enough cell-specific power to support growth in bacteria with low energy requirements. Conversely, our results indicate that oxidation of carbon monoxide (CO) primarily supports survival. Altogether, H2 is a notable energy source for marine bacteria and may influence oceanic ecology and biogeochemistry.

Pulses of labile carbon cause transient decoupling of fermentation and respiration in permeable sediments.

Dihydrogen (H2) is an important intermediate in anaerobic microbial processes, and concentrations are tightly controlled by thermodynamic limits of consumption and production. However, recent studies reported unusual H2 accumulation in permeable marine sediments under anoxic conditions, suggesting decoupling of fermentation and sulfate reduction, the dominant respiratory process in anoxic permeable marine sediments. Yet, the extent, prevalence and potential triggers for such H2 accumulation and decoupling remain unknown. We surveyed H2 concentrations in situ at different settings of permeable sand and found that H2 accumulation was only observed during a coral spawning event on the Great Barrier Reef. A flume experiment with organic matter addition to the water column showed a rapid accumulation of hydrogen within the sediment. Laboratory experiments were used to explore the effect of oxygen exposure, physical disturbance and organic matter inputs on H2 accumulation. Oxygen exposure had little effect on H2 accumulation in permeable sediments suggesting both fermenters and sulfate reducers survive and rapidly resume activity after exposure to oxygen. Mild physical disturbance mimicking sediment resuspension had little effect on H2 accumulation; however, vigorous shaking led to a transient accumulation of H2 and release of dissolved organic carbon suggesting mechanical disturbance and cell destruction led to organic matter release and transient decoupling of fermenters and sulfate reducers. In summary, the highly dynamic nature of permeable sediments and its microbial community allows for rapid but transient decoupling of fermentation and respiration after a C pulse, leading to high H2 levels in the sediment.

The Role of Cetirizine in the Changing Landscape of IV Antihistamines: A Narrative Review.

Since 1955, the only available H1 antihistamines for intravenous administration have been first-generation formulations and, of those, only intravenously administered (IV) diphenhydramine is still approved in the USA. Orally administered cetirizine hydrochloride, a second-generation H1 antihistamine, has been safely used over-the-counter for many years. In 2019, IV cetirizine was approved for the treatment of acute urticaria. In light of this approval, this narrative review discusses the changing landscape of IV antihistamines for the treatment of histamine-mediated conditions. Specifically, IV antihistamines will be discussed as a treatment option for acute urticaria and angioedema, as premedication to prevent infusion reactions related to anticancer agents and other biologics, and as an adjunct treatment for anaphylaxis and other allergic reactions. Before the development of IV cetirizine, randomized controlled trials of IV antihistamines for these indications were lacking. Three randomized controlled trials have been conducted with IV cetirizine versus IV diphenhydramine in the ambulatory care setting. A phase 3 trial of IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 262 adults who presented to the urgent care/emergency department with acute urticaria requiring antihistamines. For the primary efficacy endpoint, defined as change from baseline in a 2-h patient-rated pruritus score, non-inferiority of IV cetirizine to IV diphenhydramine was demonstrated (score - 1.6 vs - 1.5, respectively; 95% CI - 0.1, 0.3). Compared with IV diphenhydramine, IV cetirizine demonstrated fewer adverse effects including less sedation, a significantly shorter length of stay in the treatment center, and fewer returns to the treatment center at 24 and 48 h. Similar findings were demonstrated in another phase 2 acute urticaria trial and in a phase 2 trial assessing IV cetirizine for pretreatment for infusion reactions in the oncology/immunology setting. IV cetirizine is associated with similar patient outcomes, fewer adverse effects, and increased treatment center efficiency than IV diphenhydramine.

Hydrodynamic disturbance controls microbial community assembly and biogeochemical processes in coastal sediments.

The microbial community composition and biogeochemical dynamics of coastal permeable (sand) sediments differs from cohesive (mud) sediments. Tide- and wave-driven hydrodynamic disturbance causes spatiotemporal variations in oxygen levels, which select for microbial generalists and disrupt redox cascades. In this work, we profiled microbial communities and biogeochemical dynamics in sediment profiles from three sites varying in their exposure to hydrodynamic disturbance. Strong variations in sediment geochemistry, biogeochemical activities, and microbial abundance, composition, and capabilities were observed between the sites. Most of these variations, except for microbial abundance and diversity, significantly correlated with the relative disturbance level of each sample. In line with previous findings, metabolically flexible habitat generalists (e.g., Flavobacteriaceae, Woeseaiceae, Rhodobacteraceae) dominated in all samples. However, we present evidence that aerobic specialists such as ammonia-oxidizing archaea (Nitrosopumilaceae) were more abundant and active in more disturbed samples, whereas bacteria capable of sulfate reduction (e.g., uncultured Desulfobacterales), dissimilatory nitrate reduction to ammonium (DNRA; e.g., Ignavibacteriaceae), and sulfide-dependent chemolithoautotrophy (e.g., Sulfurovaceae) were enriched and active in less disturbed samples. These findings are supported by insights from nine deeply sequenced metagenomes and 169 derived metagenome-assembled genomes. Altogether, these findings suggest that hydrodynamic disturbance is a critical factor controlling microbial community assembly and biogeochemical processes in coastal sediments. Moreover, they strengthen our understanding of the relationships between microbial composition and biogeochemical processes in these unique environments.

High Return to Play Rate and Reduced Career Longevity Following Surgical Management of Athletic Pubalgia in National Basketball Association Players.

PURPOSE: To assess the effects of surgical treatment of athletic pubalgia (AP) on game use and performance metrics in National Basketball Association (NBA) players. METHODS: A retrospective review of all NBA players who underwent surgical management for AP from 1996 to 2018 was performed. A matched control group was created for comparison. The index period was defined as the entire NBA season in which surgery occurred, including the corresponding offseason. Player demographics, use (games played, games started, and minutes per game) and performance (player efficiency rating) metrics were collected for all players. Statistical analysis was performed to compare data before and after return to play. RESULTS: Thirty players with a history of surgical management for AP were included in the final analysis. Following surgery for AP, NBA players were found to have a return to play (RTP) rate of 90.91% (30/33). The average RTP following surgery was 4.73 ± 2.62 months. Compared with control athletes, athletes in the AP group played significantly fewer seasons postinjury (4.17 ± 2.70 vs 5.49 ± 3.04 seasons, respectively; P = .02). During the first year following RTP, NBA players experienced significant reductions in game use and performance, both when compared with the year prior and matched control athletes (P < .05). At 3-year follow-up, players continued to demonstrate significant reductions in game use (minutes per game, P < .05) but not performance. CONCLUSIONS: Following surgical treatment of AP, NBA players demonstrated a high RTP rate, but shortened career. A short-term reduction in game use and performance metrics was found the year of return following surgery. However, 3-year follow-up performance metrics normalized when compared with healthy controls. STUDY DESIGN: Level III; retrospective case-control study.

Effects of drift algae accumulation and nitrate loading on nitrogen cycling in a eutrophic coastal sediment.

The permeable (sandy) sediments that dominate the world's coastlines and continental shelves are highly exposed to nitrogen pollution, predominantly due to increased urbanisation and inefficient agricultural practices. This leads to eutrophication, accumulation of drift algae and changes in the reactions of nitrogen, including the potential to produce the greenhouse gas nitrous oxide (N2O). Nitrogen pollution in coastal systems has been identified as a global environmental issue, but it remains unclear how this nitrogen is stored and processed by permeable sediments. We investigated the interaction of drift algae biomass and nitrate (NO3-) exposure on nitrogen cycling in permeable sediments that were impacted by high nitrogen loading. We treated permeable sediments with increasing quantities of added macroalgal material and NO3- and measured denitrification, dissimilatory NO3- reduction to ammonium (DNRA), anammox, and nitrous oxide (N2O) production, alongside abundance of marker genes for nitrogen cycling and microbial community composition by metagenomics. We found that the presence of macroalgae dramatically increased DNRA and N2O production in sediments without NO3- treatment, concomitant with increased abundance of nitrate-ammonifying bacteria (e.g. Shewanella and Arcobacter). Following NO3- treatment, DNRA and N2O production dropped substantially while denitrification increased. This is explained by a shift in the relative abundance of nitrogen-cycling microorganisms under different NO3- exposure scenarios. Decreases in both DNRA and N2O production coincided with increases in the marker genes for each step of the denitrification pathway (narG, nirS, norB, nosZ) and a decrease in the DNRA marker gene nrfA. These shifts were accompanied by an increased abundance of facultative denitrifying lineages (e.g. Pseudomonas and Marinobacter) with NO3- treatment. These findings identify new feedbacks between eutrophication and greenhouse gas emissions, and in turn have potential to inform biogeochemical models and mitigation strategies for marine eutrophication.

Metabolic flexibility allows bacterial habitat generalists to become dominant in a frequently disturbed ecosystem.

Ecological theory suggests that habitat disturbance differentially influences distributions of habitat generalist and specialist species. While well-established for macroorganisms, this theory has rarely been explored for microorganisms. Here we tested these principles in permeable (sandy) sediments, ecosystems with much spatiotemporal variation in resource availability and physicochemical conditions. Microbial community composition and function were profiled in intertidal and subtidal sediments using 16S rRNA gene amplicon sequencing and metagenomics, yielding 135 metagenome-assembled genomes. Community composition and metabolic traits modestly varied with sediment depth and sampling date. Several taxa were highly abundant and prevalent in all samples, including within the orders Woeseiales and Flavobacteriales, and classified as habitat generalists; genome reconstructions indicate these taxa are highly metabolically flexible facultative anaerobes and adapt to resource variability by using different electron donors and acceptors. In contrast, obligately anaerobic taxa such as sulfate reducers and candidate lineage MBNT15 were less abundant overall and only thrived in more stable deeper sediments. We substantiated these findings by measuring three metabolic processes in these sediments; whereas the habitat generalist-associated processes of sulfide oxidation and fermentation occurred rapidly at all depths, the specialist-associated process of sulfate reduction was restricted to deeper sediments. A manipulative experiment also confirmed habitat generalists outcompete specialist taxa during simulated habitat disturbance. Together, these findings show metabolically flexible habitat generalists become dominant in highly dynamic environments, whereas metabolically constrained specialists are restricted to narrower niches. Thus, an ecological theory describing distribution patterns for macroorganisms likely extends to microorganisms. Such findings have broad ecological and biogeochemical ramifications.

Can We Use Functional Genetics to Predict the Fate of Nitrogen in Estuaries?

Increasing nitrogen (N) loads present a threat to estuaries, which are among the most heavily populated and perturbed parts of the world. N removal is largely mediated by the sediment microbial process of denitrification, in direct competition to dissimilatory nitrate reduction to ammonium (DNRA), which recycles nitrate to ammonium. Molecular proxies for N pathways are increasingly measured and analyzed, a major question in microbial ecology, however, is whether these proxies can add predictive power around the fate of N. We analyzed the diversity and community composition of sediment nirS and nrfA genes in 11 temperate estuaries, covering four types of land use in Australia, and analyzed how these might be used to predict N removal. Our data suggest that sediment microbiomes play a central role in controlling the magnitude of the individual N removal rates in the 11 estuaries. Inclusion, however, of relative gene abundances of 16S, nirS, nrfA, including their ratios did not improve physicochemical measurement-based regression models to predict rates of denitrification or DNRA. Co-occurrence network analyses of nirS showed a greater modularity and a lower number of keystone OTUs in pristine sites compared to urban estuaries, suggesting a higher degree of niche partitioning in pristine estuaries. The distinctive differences between the urban and pristine network structures suggest that the nirS gene could be a likely gene candidate to understand the mechanisms by which these denitrifying communities form and respond to anthropogenic pressures.

Intravenous Cetirizine Versus Intravenous Diphenhydramine for the Treatment of Acute Urticaria: A Phase III Randomized Controlled Noninferiority Trial.

STUDY OBJECTIVE: Acute urticaria is a frequent presentation in emergency departments (EDs), urgent care centers, and other clinical arenas. Treatment options are limited if diphenhydramine is the only intravenous antihistamine offered because of its short duration of action and well-known adverse effects. We evaluate cetirizine injection, the first second-generation injectable antihistamine, for acute urticaria in this multicenter, randomized, noninferiority, phase 3 clinical trial. METHODS: Adult patients presenting to EDs and urgent care centers with acute urticaria requiring an intravenous antihistamine were randomized to either intravenous cetirizine 10 mg or intravenous diphenhydramine 50 mg. The primary endpoint was the 2-hour pruritus score change from baseline, with time spent in treatment center and rate of return to treatment centers as key secondary endpoints. Frequency of sedation and anticholinergic adverse effects were also recorded. RESULTS: Among 262 enrolled patients, the 2-hour pruritus score change from baseline for intravenous cetirizine was statistically noninferior to that for intravenous diphenhydramine (-1.6 versus -1.5; 95% confidence interval -0.1 to 0.3), and in favor of cetirizine. Treatment differences also favored cetirizine for mean time spent in treatment center (1.7 versus 2.1 hours; P=.005), return to treatment center (5.5% versus 14.1%; P=.02), lower change from baseline sedation score at 2 hours (0.1 versus 0.5; P=.03), and adverse event rate (3.9% versus 13.3%). CONCLUSION: Intravenous cetirizine is an effective alternative to intravenous diphenhydramine for treating acute urticaria, with benefits of less sedation, fewer adverse events, shorter time spent in treatment center, and lower rates of revisit to treatment center.

Bilateral Luxatio Erecta Humeri With Acute Anterior-inferior Re-dislocation.

Luxatio erecta is a description for a specific and rare type of shoulder dislocation where the humeral head dislocates directly inferior. This rare form of glenohumeral dislocation accounts for only 0.5% of shoulder dislocations. It is even less common for both shoulders to be bilaterally dislocated inferiorly with the characteristic "hands up" posture. A limited number of these bilateral occurrences are described in the literature to date and most have been from higher energy trauma. We have described a low energy case of bilateral luxatio erecta and the reduction method used and the continued instability following successful reduction under procedural anesthesia.

Bacterial fermentation and respiration processes are uncoupled in anoxic permeable sediments.

Permeable (sandy) sediments cover half of the continental margin and are major regulators of oceanic carbon cycling. The microbial communities within these highly dynamic sediments frequently shift between oxic and anoxic states, and hence are less stratified than those in cohesive (muddy) sediments. A major question is, therefore, how these communities maintain metabolism during oxic-anoxic transitions. Here, we show that molecular hydrogen (H2) accumulates in silicate sand sediments due to decoupling of bacterial fermentation and respiration processes following anoxia. In situ measurements show that H2 is 250-fold supersaturated in the water column overlying these sediments and has an isotopic composition consistent with fermentative production. Genome-resolved shotgun metagenomic profiling suggests that the sands harbour diverse and specialized microbial communities with a high abundance of [NiFe]-hydrogenase genes. Hydrogenase profiles predict that H2 is primarily produced by facultatively fermentative bacteria, including the dominant gammaproteobacterial family Woeseiaceae, and can be consumed by aerobic respiratory bacteria. Flow-through reactor and slurry experiments consistently demonstrate that H2 is rapidly produced by fermentation following anoxia, immediately consumed by aerobic respiration following reaeration and consumed by sulfate reduction only during prolonged anoxia. Hydrogenotrophic sulfur, nitrate and nitrite reducers were also detected, although contrary to previous hypotheses there was limited capacity for microalgal fermentation. In combination, these experiments confirm that fermentation dominates anoxic carbon mineralization in these permeable sediments and, in contrast to the case in cohesive sediments, is largely uncoupled from anaerobic respiration. Frequent changes in oxygen availability in these sediments may have selected for metabolically flexible bacteria while excluding strict anaerobes.

Role of organic carbon, nitrate and ferrous iron on the partitioning between denitrification and DNRA in constructed stormwater urban wetlands.

Denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) are two competing nitrate reduction pathways that remove or recycle nitrogen, respectively. However, factors controlling the partitioning between these two pathways are manifold and our understanding of these factors is critical for the management of N loads in constructed wetlands. An important factor that controls DNRA in an aquatic ecosystem is the electron donor, commonly organic carbon (OC) or alternatively ferrous iron and sulfide. In this study, we investigated the role of natural organic carbon (NOC) and acetate at different OC/NO3- ratios and ferrous iron on the partitioning between DNF and DNRA using the 15N-tracer method in slurries from four constructed stormwater urban wetlands in Melbourne, Australia. The carbon and nitrate experiments revealed that DNF dominated at all OC/NO3- ratios. The higher DNF and DNRA rates observed after the addition of NOC indicates that nitrate reduction was enhanced more by NOC than acetate. Moreover, addition of NOC in slurries stimulated DNRA more than DNF. Interestingly, slurries amended with Fe2+ showed that Fe2+ had significant control on the balance between DNF and DNRA. From two out of four wetlands, a significant increase in DNRA rates (p < .05) at the cost of DNF in the presence of available Fe2+ suggests DNRA is coupled to Fe2+ oxidation. Rates of DNRA increased 1.5-3.5 times in the Fe2+ treatment compared to the control. Overall, our study provides direct evidence that DNRA is linked to Fe2+ oxidation in some wetland sediments and highlights the role of Fe2+ in controlling the partitioning between removal (DNF) and recycling (DNRA) of bioavailable N in stormwater urban constructed wetlands. In our study we also measured anammox and found that it was always <0.05% of total nitrate reduction in these sediments.

Bedforms as Biocatalytic Filters: A Pumping and Streamline Segregation Model for Nitrate Removal in Permeable Sediments.

Bedforms are a focal point of carbon and nitrogen cycling in streams and coastal marine ecosystems. In this paper, we develop and test a mechanistic model, the "pumping and streamline segregation" or PASS model, for nitrate removal in bedforms. The PASS model dramatically reduces computational overhead associated with modeling nitrogen transformations in bedforms and reproduces (within a factor of 2 or better) previously published measurements and models of biogeochemical reaction rates, benthic fluxes, and in-sediment nutrient and oxygen concentrations. Application of the PASS model to a diverse set of marine and freshwater environments indicates that (1) physical controls on nitrate removal in a bedform include the pore water flushing rate, residence time distribution, and relative rates of respiration and transport (as represented by the Damkohler number); (2) the biogeochemical pathway for nitrate removal is an environment-specific combination of direct denitrification of stream nitrate and coupled nitrification-denitrification of stream and/or sediment ammonium; and (3) permeable sediments are almost always a net source of dissolved inorganic nitrogen. The PASS model also provides a mechanistic explanation for previously published empirical correlations showing denitrification velocity (N2 flux divided by nitrate concentration) declines as a power law of nitrate concentration in a stream (Mulholland et al. Nature, 2008, 452, 202-205).

Transport zonation limits coupled nitrification-denitrification in permeable sediments.

Measurement of biogeochemical processes in permeable sediments (including the hyporheic zone) is difficult because of complex multidimensional advective transport. This is especially the case for nitrogen cycling, which involves several coupled redox-sensitive reactions. To provide detailed insight into the coupling between ammonification, nitrification and denitrification in stationary sand ripples, we combined the diffusion equilibrium thin layer (DET) gel technique with a computational reactive transport biogeochemical model. The former approach provided high-resolution two-dimensional distributions of NO3(-) and (15)N-N2 gas. The measured two-dimensional profiles correlate with computational model simulations, showing a deep pool of N2 gas forming, and being advected to the surface below ripple peaks. Further isotope pairing calculations on these data indicate that coupled nitrification-denitrification is severely limited in permeable sediments because the flow and transport field limits interaction between oxic and anoxic pore water. The approach allowed for new detailed insight into subsurface denitrification zones in complex permeable sediments.

Seroprevalence study using oral rapid HIV testing in a large urban emergency department.

BACKGROUND: The Centers for Disease Control (CDC) recommends universal human immunodeficiency virus (HIV) testing for patients aged 13-64 years in health care settings where the seroprevalence is>0.1%. Rapid HIV testing has several advantages; however, recent studies have raised concerns about false positives in populations with low seroprevalence. STUDY OBJECTIVES: To determine the seroprevalence of HIV in our Emergency Department (ED) population, understand patient preferences toward rapid testing in the ED, and evaluate the performance of a rapid oral HIV test. METHODS: A serosurvey offered oral rapid HIV 1/2 testing (OraQuick ADVANCE, Bethlehem, PA) to a convenience sample of 1348 ED patients beginning August 2008. Subjects declining participation were asked to complete an opt-out survey. RESULTS: 1000 patients were tested. Twelve had positive results (1.2%), including one who had newly diagnosed HIV infection; 988 patients tested negative. Of these, 335 (33.3%) had never been tested; 640 had prior history of a negative HIV test. No false-positive rapid HIV results were detected; 98.7% received the results of their preliminary HIV test, including 100% of those who tested positive. Most subjects who declined testing cited either a recent negative HIV test (160/348) or low perceived risk (65/348). A minority cited a concern regarding their privacy (11/348) or that the test might delay their treatment (7/348). CONCLUSIONS: The seroprevalence estimate of 1.2% was above the rate recommended by the CDC for routine universal opt-out testing in our study population. The acceptance rate of rapid HIV testing and the percentage of patients receiving results approximated other recent reports.