Endoscopic evaluation during the COVID-19 pandemic: Observational study of the experience in community practices.

Endoscopic screening is used widely to minimize the rates of colorectal cancer cases and deaths. During highly virulent infectious disease pandemics such as the coronavirus disease 2019 (COVID-19) pandemic, it is essential to weigh the risks and benefits of receiving endoscopy, especially in regions with moderately high viral infection rates. An observational study was conducted to assess the number of patients seen for endoscopic procedure at 2 of our surgery centers. Reasons for their procedure were collected in addition to information regarding any positive COVID-19 cases. This study considers the rate of severe acute respiratory syndrome coronavirus 2 infection along with the number of colorectal cancer cases encountered at a community endoscopy center to suggest that the benefits of undergoing endoscopic evaluation may outweigh the risks of attending an endoscopy procedure during the COVID-19 pandemic. One of the main reasons patients underwent endoscopic procedure was for colon cancer screenings (41.9%), and 5 of 1020 patients seen during the observation period were diagnosed with cancer. Of these 1020 patients, 8 were found to have positive tests for COVID-19 within 2 to 4 weeks after their procedure.

Ultrafast nanometric imaging of energy flow within and between single carbon dots.

Time- and space-resolved excited states at the individual nanoparticle level provide fundamental insights into heterogeneous energy, electron, and heat flow dynamics. Here, we optically excite carbon dots to image electron-phonon dynamics within single dots and nanoscale thermal transport between two dots. We use a scanning tunneling microscope tip as a detector of the optically excited state, via optical blocking of electron tunneling, to record movies of carrier dynamics in the 0.1-500-ps time range. The excited-state electron density migrates from the bulk to molecular-scale (∼1 nm2) surface defects, followed by heterogeneous relaxation of individual dots to either long-lived fluorescent states or back to the ground state. We also image the coupling of optical phonons in individual carbon dots with conduction electrons in gold as an ultrafast energy transfer mechanism between two nearby dots. Although individual dots are highly heterogeneous, their averaged dynamics is consistent with previous bulk optical spectroscopy and nanoscale heat transfer studies, revealing the different mechanisms that contribute to the bulk average.

Unraveling the Fluorescence Mechanism of Carbon Dots with Sub-Single-Particle Resolution.

Unlike quantum dots, photophysical properties of carbon dots (CDs) are not strongly correlated with particle size. The origin of CD photoluminescence has been related to sp2 domain size and the abundance of oxidized surface defects. However, direct imaging of surface-accessible spatially localized oxidized defects is still lacking. In this work, solvothermal-synthesized CDs are fractionated into different colors by polarity-based chromatography. We then study the mechanism of CD fluorescence by directly imaging individual CDs with subparticle resolution by scanning tunneling microscopy. Density of states imaging of CDs reveals that the graphitic core has a large bandgap that is inconsistent with observed fluorescence wavelength, whereas localized defects have smaller electronic gaps for both red-emitting dots (rCDs) and blue-emitting dots (bCDs). For individual bCDs within our laser tuning range, we directly image optically active surface defects (ca. 1-3 nm in size) and their bandgaps, which agree with the emission wavelength of the ensemble from which the bCDs were taken. We find that the emissive defects are not necessarily the ones with the smallest gap, consistent with quantum yields less than unity (0.1-0.26). X-ray photoelectron spectroscopy and pH-dependent fluorescence titration show that oxygen-containing surface-accessible protonatable functional groups (e.g., phenolic -OH, -COOH) define the chemical identity of the defects. This observation explains why we detect neither long-lived optical excitation of the core nor a correlation between size and emission wavelength. Instead, control over the number of oxygen-containing defects defines the emission wavelength, with more oxidized defects at the surface producing redder emission wavelengths.

Excited-State Imaging of Single Particles on the Subnanometer Scale.

At the intersection of spectroscopy and microscopy lie techniques that are capable of providing subnanometer imaging of excited states of individual molecules or nanoparticles. Such approaches are particularly important for imaging macromolecules or nanoparticles large enough to have a high probability of containing a defect. These inevitable defects often control properties and function despite an otherwise ideal structure. We discuss real-space imaging techniques such as using scanning tunneling microscopy tips to enhance optical measurements and electron energy-loss spectroscopy in a scanning transmission electron microscope, which is based on focused electron beams to obtain high-resolution spatial information on excited states. The outlook for these methods is bright, as they will provide critical information for the characterization and improvement of energy-switching, electron-switching, and energy-harvesting materials.

Multi-scale dynamics at the glassy silica surface.

Silica-based glass is a household name, providing insulation for windows to microelectronics. The debate over the types of motions thought to occur in or on SiO2 glass well below the glass transition temperature continues. Here, we form glassy silica films by oxidizing the Si(100) surface (from 0.5 to 1.5 nm thick, to allow tunneling). We then employ scanning tunneling microscopy in situ to image and classify these motions at room temperature on a millisecond to hour time scale and 50-pm to 5-nm length scale. We observe two phenomena on different time scales. Within minutes, compact clusters with an average diameter of several SiO2 glass-forming units (GFUs) hop between a few (mostly two) configurations, hop cooperatively (facilitation), and merge into larger clusters (aging) or split into smaller clusters (rejuvenation). Within seconds, Si-O-Si bridges connect two GFUs within a single cluster flip, providing a vibrational fine structure to the energy landscape. We assign the vibrational fine structure using electronic structure calculations. Calculations also show that our measured barrier height for whole cluster hopping at the glass surface (configurational dynamics) is consistent with the configurational entropy predicted by thermodynamic models of the glass transition and that the vibrational entropy for GFU flipping and configurational entropy for cluster hopping are comparable (on a per GFU basis).

Imaging of Carbon Nanotube Electronic States Polarized by the Field of an Excited Quantum Dot.

Efficient heat dissipation and large gate capacitance have made carbon nanotube field-effect transistors (CNT FETs) devices of interest for over 20 years. The mechanism of CNT FETs involves localization of the electronic structure due to a transverse electric field, yet little is known about the localization effect, nor has the electronic polarization been visualized directly. Here, we co-deposit PbS quantum dots (QDs) with CNTs and optically excite the QD so its excited-state dipolar field biases the local environment of a CNT. Using single-molecule absorption scanning tunneling microscopy, we show that the electronic states of the CNT become transversely localized. By nudging QDs to different distances from the CNT, the magnitude of the localization can be controlled. Different bias voltages probe the degree of localization in different CNT excited states. A simple tight-binding model for the CNT in an electrostatic field provides a semiquantitative model for the observed behavior.

Poor Adherence to Guidelines for Treatment of Chronic Hepatitis B Virus Infection at Primary Care and Referral Practices.

BACKGROUND & AIMS: The American Association for the Study of Liver Diseases (AASLD) guidelines for treatment of chronic hepatitis B virus (HBV) infection have changed with time. We assessed rates of treatment evaluation and initiation in patients with chronic HBV infection from different practice settings in the past 14 years. METHODS: Treatment-naive patients with chronic HBV infection were recruited from different practice settings in California from January 2002 through December 2016. The study population comprised 4130 consecutive, treatment-naive patients with chronic HBV infection seen by community primary care physicians (n = 616), community gastroenterologists (n = 2251), or university hepatologists (n = 1263). Treatment eligibility was assessed using data from the first 6 months after initial presentation based on AASLD criteria adjusted for changes over time. RESULTS: Within the first 6 months of care, the proportions of patients evaluated by all 3 relevant tests (measurements of alanine aminotransferase, hepatitis B virus e antigen, and HBV DNA levels) were as follows: 36.69% in community primary care, 59.80% in gastroenterologist care, and 79.97% in hepatology care (P < .0001 among the 3 groups). Higher proportions of patients were eligible for treatment in specialty practices: 12.76% in community primary care, 24.96% in gastroenterologist care, and 29.43% in hepatology care (P < .0001). Among treatment-eligible patients, there was no significant difference in the proportions of patients who began antiviral therapy between those receiving treatment from a gastroenterologist (55.65%) vs a hepatologist (57.90%; P = .56). Of 243 evaluable patients receiving community primary care, only 31 were eligible for treatment and only 12 of these (38.71%) received treatment. CONCLUSIONS: In an analysis of patients receiving care for chronic HBV infection, we found the proportions evaluated and receiving treatment to be suboptimal, according to AASLD criteria, in all practice settings. However, rates of evaluation and treatment were lowest for patients receiving community primary care.

STM Imaging of Localized Surface Plasmons on Individual Gold Nanoislands.

An optically modulated scanning tunneling microscopy technique developed for measurement of single-molecule optical absorption is used here to image the light absorption by individual Au nanoislands and Au nanostructures. The technique is shown to spatially map, with nanometer resolution, localized surface plasmons (LSPs) excited within the nanoislands. Electrodynamic simulations demonstrate the correspondence of the measured images to plasmonic near-field intensity maps. The optical STM imaging technique captures the wavelength, polarization, and geometry dependence of the LSP resonances and their corresponding near-fields. Thus, we introduce a tool for real-space, nanometer-scale visualization of optical energy absorption, transport, and dissipation in complex plasmonic nanostructures.

Orientation-dependent imaging of electronically excited quantum dots.

We previously demonstrated that we can image electronic excitations of quantum dots by single-molecule absorption scanning tunneling microscopy (SMA-STM). With this technique, a modulated laser beam periodically saturates an electronic transition of a single nanoparticle, and the resulting tunneling current modulation ΔI(x0, y0) maps out the SMA-STM image. In this paper, we first derive the basic theory to calculate ΔI(x0, y0) in the one-electron approximation. For near-resonant tunneling through an empty orbital "i" of the nanostructure, the SMA-STM signal is approximately proportional to the electron density φix0,y02 of the excited orbital in the tunneling region. Thus, the SMA-STM signal is approximated by an orbital density map (ODM) of the resonantly excited orbital at energy Ei. The situation is more complex for correlated electron motion, but either way a slice through the excited electronic state structure in the tunneling region is imaged. We then show experimentally that we can nudge quantum dots on the surface and roll them, thus imaging excited state electronic structure of a single quantum dot at different orientations. We use density functional theory to model ODMs at various orientations, for qualitative comparison with the SMA-STM experiment. The model demonstrates that our experimentally observed signal monitors excited states, localized by defects near the surface of an individual quantum dot. The sub-nanometer super-resolution imaging technique demonstrated here could become useful for mapping out the three-dimensional structure of excited states localized by defects within nanomaterials.

Imaging and Manipulating Energy Transfer Among Quantum Dots at Individual Dot Resolution.

Many processes of interest in quantum dots involve charge or energy transfer from one dot to another. Energy transfer in films of quantum dots as well as between linked quantum dots has been demonstrated by luminescence shift, and the ultrafast time-dependence of energy transfer processes has been resolved. Bandgap variation among dots (energy disorder) and dot separation are known to play an important role in how energy diffuses. Thus, it would be very useful if energy transfer could be visualized directly on a dot-by-dot basis among small clusters or within films of quantum dots. To that effect, we report single molecule optical absorption detected by scanning tunneling microscopy (SMA-STM) to image energy pooling from donor into acceptor dots on a dot-by-dot basis. We show that we can manipulate groups of quantum dots by pruning away the dominant acceptor dot, and switching the energy transfer path to a different acceptor dot. Our experimental data agrees well with a simple Monte Carlo lattice model of energy transfer, similar to models in the literature, in which excitation energy is transferred preferentially from dots with a larger bandgap to dots with a smaller bandgap.

Long-term follow-up and suboptimal treatment rates of treatment-eligible chronic hepatitis B patients in diverse practice settings: a gap in linkage to care.

BACKGROUND AND AIMS: Despite available effective therapies, only a minority of patients with chronic hepatitis B (CHB) receive treatment. Our goal is to study treatment rates and time to treatment initiation in patients who meet treatment criteria on long-term follow-up. METHODS: We performed a retrospective cohort study of 608 consecutive treatment-eligible patients with CHB (by 2008 US Panel or 2009 American Association for the Study of Liver Disease (AASLD) criteria) at a US community gastroenterology clinic and a university liver clinic between 2007 and 2011. Patients were observed until they started treatment or last follow-up if untreated. RESULTS: Mean age was 44 and most were Asian (96%) with community patients being younger and having lower alanine aminotransferase (ALT) levels. A total of 62% started treatment, and 38% remained untreated after median follow-up of 17 months (IQR=1-40 months). Overall, treatment rate was significantly higher at university liver clinic than in the community (66.7% vs 59.9%, p=0.01). In multivariate analysis, older age (HR 1.02, p=0.002), male gender (HR 1.37, p=0.02), and baseline ALT >45 U/L for males and >29 U/L for females (HR 2.24, p<0.0001) were significant predictors of treatment initiation, but not practice setting. CONCLUSIONS: Approximately 40% of treatment-eligible patients still have not started treatment on longer follow-up. Treatment rates were higher at university clinics, but practice setting was not a predictor for treatment, but older age, male gender, and higher ALT levels were. Further studies are needed to determine the barriers for treatment initiation and to improve treatment rates in treatment-eligible patients.

Tenofovir monotherapy after achieving complete viral suppression on entecavir plus tenofovir combination therapy.

OBJECTIVES: It is unclear whether patients with chronic hepatitis B with partial response to entecavir (ETV) who have achieved complete viral suppression (CVS) with ETV plus tenofovir (TDF) combination therapy maintain CVS if switched to TDF or ETV. Our goal was to examine virologic outcomes in such patients. METHODS: This is a retrospective cohort study of 57 ETV partial responders with chronic hepatitis B who showed CVS on ETV+TDF combination therapy, who were switched back to monotherapy with either ETV (n=16) or TDF (n=18), or continued on combination therapy (n=23). The majority of patients were Asian (91%) and male (65%), with a mean age of 41±12 years. RESULTS: The patients switched back to ETV had significantly higher rates of virologic breakthrough by 6 months after the switch compared with their TDF counterparts (88 vs. 39%, P=0.004). Patients who remained on ETV+TDF also had virologic breakthrough, due to either confirmed or suspected nonadherence. On multivariate analysis inclusive of age, sex, and hepatitis B virus DNA levels at initiation of combination therapy, ETV (compared with TDF) was found to be an independent predictor for virologic breakthrough (odds ratio 112.7, P=0.03), as well as duration of CVS of less than 12 months while on ETV+TDF (odds ratio 60.2, P=0.03). CONCLUSION: TDF monotherapy, especially in those who have had CVS for at least 12 months on combination therapy, may be considered for some ETV partial responders who have achieved CVS with combination therapy, given the financial advantage and convenience of monotherapy.

Safety and efficacy of entecavir in adefovir-experienced patients.

BACKGROUND AND AIM: Suboptimal viral suppression with adefovir (ADV) poses a challenge in managing chronic hepatitis B. Few studies have evaluated the efficacy of entecavir (ETV) in ADV-experienced patients. Our aim is to assess treatment effectiveness of ETV in ADV-experienced patients. METHODS: ADV-experienced patients switched to ETV were enrolled from six US clinics. Patients completed a median of 24 months of ETV after switch. Patients were categorized into partial responders (detectable HBV-DNA at switch) or complete responders (undetectable HBV-DNA at switch) to ADV. Primary and secondary outcome measurements were complete viral suppression (CVS, HBV-DNA < 60 IU/mL) and biochemical response (BR, alanine aminotransferase [ALT] < 40 U/L), respectively. RESULTS: A total of 120 patients were included in the analysis (80 ADV partial responders; 40 ADV complete responders). In partial responders, CVS rate was 84% after 24 months of ETV. BR rate was 58% at switch to ETV and increased to 90% after 24 months. All complete responders continued to experience CVS after switch. On multivariate analysis inclusive of age, male gender, ALT level at switch, and history of lamivudine (LAM) exposure, we identified positive, hepatitis B e antigen status before ADV and higher HBV-DNA level at time of switch as significant independent negative predictors of CVS. In eight patients with ADV resistance, seven achieved CVS after 24 months of ETV, and all achieved BR. CONCLUSION: In ADV-experienced patients, high rates of CVS and BR can be achieved/sustained after switching to ETV, including those with ADV resistance or with prior exposure to LAM.

Mutations in HBV DNA polymerase associated with nucleos(t)ide resistance are rare in treatment-naive patients.

BACKGROUND & AIMS: Prior studies have detected hepatitis B virus (HBV) DNA polymerase mutations in treatment-naive patients. However, most of these studies used either direct polymerase chain reaction sequencing, which detects these mutations with low levels of sensitivity, or patient cohorts that were not well-characterized. We investigated the prevalence of HBV mutations in DNA polymerase by using a line probe assay. METHODS: In a prospective, cross-sectional study, we enrolled 198 treatment-naive patients with chronic hepatitis B (52.5% male; mean age, 41 years) from February 2009 to May 2011 from 3 gastroenterology and liver clinics in Northern California. Exclusion criteria included infection with hepatitis C or D viruses or human immunodeficiency virus. All patients completed a questionnaire (to determine demographics, history of liver disease, prior treatments, family medical history, drug and alcohol use, and environmental risk factors for hepatitis) that was administered by a research coordinator; mutations in HBV DNA polymerase were detected by using the INNO-LiPA HBV DR v.3 assay. RESULTS: Most patients were Vietnamese (48.5%) or Chinese (36.4%) and were infected with HBV genotypes B (67.5%) or C (24.2%). Mutations in HBV DNA polymerase were found in 2 patients (1%), rtI233V (n = 1) and rtM250M/L (n = 1). CONCLUSIONS: In a multicenter prospective study of treatment-naive patients with chronic hepatitis B, we detected mutations in HBV DNA polymerase in only 1%. Because of the low prevalence of these mutations and the uncertain clinical significance of such quasispecies, routine HBV DNA polymerase mutation analysis cannot be recommended before initiation of antiviral therapy for treatment-naive patients with chronic hepatitis B. The analysis requires further molecular and clinical studies.

Similar response to entecavir 0.5 and 1.0 mg in treatment-naïve chronic hepatitis B patients: a case-control study.

BACKGROUND AND AIMS: The dose recommendation for entecavir (ETV) is 0.5 mg daily for treatment-naïve chronic hepatitis B (CHB) patients and 1.0 mg daily for lamivudine-refractory patients; however, few data are available for the efficacy of a 1.0-mg daily dose in treatment-naïve CHB patients. Our goal is to examine the treatment outcome of treatment-naïve patients placed on ETV 0.5 mg or ETV 1.0 mg daily through week 48. METHODS: Cases were 40 consecutive hepatitis B e antigen (HBeAg)-positive CHB patients treated with ETV 1.0 mg daily between January 2005 and September 2010, and controls were 40 consecutive CHB patients treated with ETV 0.5 mg daily between January 2005 and September 2010 at three US gastroenterology/liver clinics. Controls were matched for age (±5 years), sex, HBeAg, and baseline hepatitis B virus (HBV) DNA (±0.5 log10 IU/ml). Complete viral suppression was defined as undetectable HBV DNA by polymerase chain reaction (<100 IU/ml). RESULTS: Both groups had similar distributions of age (38 ± 11 years), male patients (55 %), and mean HBV DNA (7.7 ± 1.1 log10 IU/ml). The complete viral suppression rate was similar in both cases and controls through week 24 (15 vs. 15 %, p = 1.00) and week 48 (22 vs. 36 %, p = 0.17). Non-adherence was reported in three patients in the ETV 1.0 mg daily cohort at week 48. CONCLUSIONS: There were no significant differences in the proportion of patients with complete viral suppression in patients treated with ETV 0.5 mg daily or the higher daily dose of 1.0 mg.

Less-established risk factors are common in Asian Americans with hepatitis C virus: a case-controlled study.

BACKGROUND AND AIMS: The Centers for Disease Control and Prevention recommend screening for hepatitis C virus (HCV) in patients with injection drug use, blood transfusion before 1992, stigmata of liver disease, or born between 1945 and 1965. The purpose of this study was to examine risk factors for HCV acquisition in Asian Americans. METHODS: This was a case-controlled study, with 471 consecutive patients testing positive for anti-HCV between January 2001 and December 2008. Controls included 471 patients with negative HCV matched at a one-to-one ratio for sex, age (±5 years), and ethnicity. RESULTS: For Asian patients, the most common risk factors were blood transfusion and acupuncture or exposure to dirty needles (27 and 20 %, respectively). On multiple logistic regression, potential predictors for a positive anti-HCV test in Asians were acupuncture or exposure to dirty needles (OR = 12.9, P < 0.0001), body tattoo (OR = 12.0, P = 0.001), and history of blood transfusion (OR = 5.7, P < 0.0001). DISCUSSION: Acupuncture and exposure to dirty needles are independent risk factors of HCV infection. Asians coming from endemic areas should be screened for HCV even when commonly-known risk factors for Western patients are not present.

Low incidence of hepatitis B e antigen seroconversion in patients treated with oral nucleos(t)ides in routine practice.

BACKGROUND AND AIM: Treatment end-point of therapy for patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) includes HBeAg seroconversion, which ranges from 15% to 22% after 1 year of oral nucleos(t)ides according to clinical trials. Our goal was to determine the incidence and predictors of HBeAg seroconversion in such patients in routine clinical practice because they may differ than reported rates. METHODS: We conducted a retrospective cohort study of 333 consecutive treatment-naïve HBeAg-positive patients who were treated for CHB between 1/2000 and 6/2010 at three gastroenterology and liver clinics in the USA. Primary study end-point was HBeAg seroconversion-loss of HBeAg and antibody to HBeAg (anti-HBe) development. RESULTS: The majority of patients were Asian (96%). Median treatment duration prior to HBeAg seroconversion was 50 (range 26-52) weeks. Of the 333 study patients, 25% received lamivudine, 16% adefovir, 51% entecavir, and 8% tenofovir. HBeAg seroconversion at month 12 was 8.2%. On multivariate analysis inclusive of age, gender, and antiviral agents, independent predictors for HBeAg seroconversion at month 12 were hepatitis B virus DNA < 7.5 log10 IU/mL (hazard ratio [HR] = 2.59 [1.04-6.44]), P = 0.041) and alanine transaminase (ALT) > 1.5 × upper normal limit (HR = 2.86 [1.05-7.81], P = 0.040), but not the choice of nucleos(t)ides. CONCLUSIONS: The HBeAg seroconversion rate seen in clinical settings for oral nucleos(t)ides appears much lower than those reported in pivotal trials, especially in patients with lower ALT and higher HBV DNA levels. HBeAg-positive patients should be counseled about the high possibility of the long treatment duration required to achieve recommended treatment end-points.

Low hepatitis B envelope antigen seroconversion rate in chronic hepatitis B patients on long-term entecavir 0.5 mg daily in routine clinical practice.

AIM: Data from registration trials with highly selective patients have shown that hepatitis B envelope antigen (HBeAg)-positive patients with chronic hepatitis B respond well to entecavir (ETV) 0.5 mg daily, with an HBeAg seroconversion rate of 21% at 12 months. However, there are varying data on the treatment outcomes of ETV 0.5 mg daily in routine clinical settings, with seroconversion rates at 12 months ranging from 8 to 48% in studies limited to 44-90 patients from centers in Asia, Europe, and South America. MATERIALS AND METHODS: In the present study, we examined long-term treatment efficacy and tolerability in 136 consecutive treatment-naive HBeAg-positive chronic hepatitis B patients treated between January 2005 and January 2011 with ETV 0.5 mg daily at community clinics and tertiary centers in the USA. The primary study end point was HBeAg seroconversion. RESULTS: Sixty-one percent of HBeAg-positive patients were men, mean age 39 ± 12 years, median hepatitis B virus DNA 7.48 (3.7-9.8) log10 IU/ml, median alanine aminotransferase 67 (14-1077) U/l, and median treatment duration 18 (6-60) months. At months 12, 24, and 36, complete viral suppression rates were 41, 66, and 85% and HBeAg seroconversion rates were 4.8, 20, and 30%, respectively. No patients experienced adverse events or developed genotypic resistance to ETV. CONCLUSION: In clinical settings, ETV is highly tolerable and potent at suppressing hepatitis B viremia; however, the rates of HBeAg seroconversion appear to be much lower than those reported, highlighting the importance of appropriate counseling and planning for long-term therapy.

High proportion of hepatitis C virus in community Asian American patients with non-liver-related complaints.

GOALS AND BACKGROUND: Besides United States population born between 1945 and 1965, screening for hepatitis C virus (HCV) is not recommended for the general US population. However, HCV may be more prevalent in certain subgroups and screening may be warranted. The goal of this study was to examine the proportion of HCV in a large sample of community Asian American patients presenting for non-liver-related complaints. STUDY: We conducted a cross-sectional study of 1246 patients tested for hepatitis C virus antibodies (anti-HCV) referred to 2 gastroenterology clinics for non-liver-related gastrointestinal reasons between January 2001 and February 2011. We determined HCV status and patient history via electronic medical record review. RESULTS: Of the 1246 study patients tested for anti-HCV, the majority were Asian (81.4%) and 29 Asian patients (2.9%) had positive anti-HCV. HCV proportion in the remaining 232 non-Asians (non-Hispanic whites and Hispanics) was 1.7%. Asians with positive anti-HCV were more likely to have had blood transfusions (31.0% vs. 6.6%, P<0.0001) or acupuncture (10.3% vs. 1.5%, P<0.0001). Of the 976 Asian patients with hepatitis B surface antigen testing, 38 (3.9%) also had detectable hepatitis B surface antigen. CONCLUSIONS: Among patients seen at community gastroenterology clinics for non-liver-related reasons, HCV proportion was 1.7% for non-Asians and 2.9% for Asians. Screening for HCV should be offered to high-risk patients presenting to gastroenterology clinics with unrelated gastrointestinal complaints.