Continental Scale Hydrostratigraphy: Comparing Geologically Informed Data Products to Analytical Solutions.

This study synthesizes two different methods for estimating hydraulic conductivity (K) at large scales. We derive analytical approaches that estimate K and apply them to the contiguous United States. We then compare these analytical approaches to three-dimensional, national gridded K data products and three transmissivity (T) data products developed from publicly available sources. We evaluate these data products using multiple approaches: comparing their statistics qualitatively and quantitatively and with hydrologic model simulations. Some of these datasets were used as inputs for an integrated hydrologic model of the Upper Colorado River Basin and the comparison of the results with observations was used to further evaluate the K data products. Simulated average daily streamflow was compared to daily flow data from 10 USGS stream gages in the domain, and annually averaged simulated groundwater depths are compared to observations from nearly 2000 monitoring wells. We find streamflow predictions from analytically informed simulations to be similar in relative bias and Spearman's rho to the geologically informed simulations. R-squared values for groundwater depth predictions are close between the best performing analytically and geologically informed simulations at 0.68 and 0.70 respectively, with RMSE values under 10 m. We also show that the analytical approach derived by this study produces estimates of K that are similar in spatial distribution, standard deviation, mean value, and modeling performance to geologically-informed estimates. The results of this work are used to inform a follow-on study that tests additional data-driven approaches in multiple basins within the contiguous United States.

Continental Scale Hydrostratigraphy: Basin-Scale Testing of Alternative Data-Driven Approaches.

Integrated hydrological modeling is an effective method for understanding interactions between parts of the hydrologic cycle, quantifying water resources, and furthering knowledge of hydrologic processes. However, these models are dependent on robust and accurate datasets that physically represent spatial characteristics as model inputs. This study evaluates multiple data-driven approaches for estimating hydraulic conductivity and subsurface properties at the continental-scale, constructed from existing subsurface dataset components. Each subsurface configuration represents upper (unconfined) hydrogeology, lower (confined) hydrogeology, and the presence of a vertical flow barrier. Configurations are tested in two large-scale U.S. watersheds using an integrated model. Model results are compared to observed streamflow and steady state water table depth (WTD). We provide model results for a range of configurations and show that both WTD and surface water partitioning are important indicators of performance. We also show that geology data source, total subsurface depth, anisotropy, and inclusion of a vertical flow barrier are the most important considerations for subsurface configurations. While a range of configurations proved viable, we provide a recommended Selected National Configuration 1 km resolution subsurface dataset for use in distributed large-and continental-scale hydrologic modeling.

MIL-88B(Fe)-NH2: an amine-functionalized metal-organic framework for application in a sensitive electrochemical sensor for Cd2+, Pb2+, and Cu2+ ion detection.

We propose here an electrochemical platform for multi-heavy metal ion detection in water based on MIL-88B(Fe)-NH2, an amine-functioned metal-organic framework (MOF) for modifying the surface of a glassy carbon electrode (GCE). Herein, MIL-88B(Fe)-NH2 with abundant functionalized amine groups can play the role of capture sites for the enrichment of metal ions before electrochemical oxidation sensing. MIL-88B(Fe)-NH2 was synthesized under optimized conditions through a solvothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. MIL-88B(Fe)-NH2 was then drop-casted on GCE to electrochemically determine the Cd2+, Pb2+ and Cu2+ ion concentrations by differential pulse voltammetry (DPV). The electrochemical sensor exhibits excellent electrochemical performance toward Cd2+, Pb2+ and Cu2+ ions in the large linear ranges of 0.025-1.000 µM, 0.3-10.0 µM and 0.6-10.0 µM with limits of detection that are 2.0 × 10-10 M, 1.92 × 10-7 M and 3.81 × 10-7 M, respectively. The fabricated sensor also shows high reliability and good selectivity. This MIL-88B(Fe)-NH2 application strategy is promising for the evaluation of various heavy metal ions in water.

Identifying Transcription Factors That Prefer Binding to Methylated DNA Using Reduced G-Gap Dipeptide Composition.

Transcription factors (TFs) play an important role in gene expression and regulation of 3D genome conformation. TFs have ability to bind to specific DNA fragments called enhancers and promoters. Some TFs bind to promoter DNA fragments which are near the transcription initiation site and form complexes that allow polymerase enzymes to bind to initiate transcription. Previous studies showed that methylated DNAs had ability to inhibit and prevent TFs from binding to DNA fragments. However, recent studies have found that there were TFs that could bind to methylated DNA fragments. The identification of these TFs is an important steppingstone to a better understanding of cellular gene expression mechanisms. However, as experimental methods are often time-consuming and labor-intensive, developing computational methods is essential. In this study, we propose two machine learning methods for two problems: (1) identifying TFs and (2) identifying TFs that prefer binding to methylated DNA targets (TFPMs). For the TF identification problem, the proposed method uses the position-specific scoring matrix for data representation and a deep convolutional neural network for modeling. This method achieved 90.56% sensitivity, 83.96% specificity, and an area under the receiver operating characteristic curve (AUC) of 0.9596 on an independent test set. For the TFPM identification problem, we propose to use the reduced g-gap dipeptide composition for data representation and the support vector machine algorithm for modeling. This method achieved 82.61% sensitivity, 64.86% specificity, and an AUC of 0.8486 on another independent test set. These results are higher than those of other studies on the same problems.

Characteristics, in-hospital management, and complications of acute myocardial infarction in northern and Central Vietnam.

INTRODUCTION: Contemporary data on the epidemiology of acute myocardial infarction (AMI) in Vietnam are extremely limited. METHODS: We established population-based registries of residents from 2 provinces in a northern urban (Hai Phong), and a central rural (Thanh Hoa), province of Vietnam hospitalized with a validated first AMI in 2018. We described patient characteristics, in-hospital management and clinical complications, and estimated incidence rates of AMI in these two registries. RESULTS: A total of 785 patients (mean age = 71.2 years, 64.7% men) were admitted to the two hospitals with a validated first AMI. Approximately 64% of the AMI cases were ST-segment-elevation AMI. Patients from Thanh Hoa compared with Hai Phong were more likely to delay seeking acute hospital care. The incidence rates (per 100,000 population) of initial AMI in Thanh Hoa and Hai Phong were 16 and 30, respectively. Most patients were treated with aspirin (Thanh Hoa: 96%; Hai Phong: 90%) and statins (both provinces: 91%) during their hospitalization. A greater proportion of patients in Hai Phong (69%) underwent percutaneous revascularization than those in Thanh Hoa (58%). The most common in-hospital complications were heart failure (both provinces:12%), cardiogenic shock (Thanh Hoa: 10%; Hai phong: 7%); and cardiac arrest (both provinces: 9%). The in-hospital case-fatality rates for patients from Thanh Hoa and Hai Phong were 6.8% and 3.8%, respectively. CONCLUSIONS: The incidence and hospital case-fatality rates of AMI were low in two Vietnamese provinces. Extent of pre-hospital delay and in-hospital use of evidence-based therapies were suboptimal, being more prominent in the rural province.

Hydrothermally synthesized nanostructured LiMnxFe1-xPO4 (x = 0-0.3) cathode materials with enhanced properties for lithium-ion batteries.

Nanostructured cathode materials based on Mn-doped olivine LiMnxFe1-xPO4 (x = 0, 0.1, 0.2, and 0.3) were successfully synthesized via a hydrothermal route. The field-emission scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyzed results indicated that the synthesized LiMnxFe1-xPO4 (x = 0, 0.1, 0.2, and 0.3) samples possessed a sphere-like nanostructure and a relatively homogeneous size distribution in the range of 100-200 nm. Electrochemical experiments and analysis showed that the Mn doping increased the redox potential and boosted the capacity. While the undoped olivine (LiFePO4) had a capacity of 169 mAh g-1 with a slight reduction (10%) in the initial capacity after 50 cycles (150 mAh g-1), the Mn-doped olivine samples (LiMnxFe1-xPO4) demonstrated reliable cycling tests with negligible capacity loss, reaching 151, 147, and 157 mAh g-1 for x = 0.1, 0.2, and 0.3, respectively. The results from electrochemical impedance spectroscopy (EIS) accompanied by the galvanostatic intermittent titration technique (GITT) have resulted that the Mn substitution for Fe promoted the charge transfer process and hence the rapid Li transport. These findings indicate that the LiMnxFe1-xPO4 nanostructures are promising cathode materials for lithium ion battery applications.

Increase in white blood cell count is associated with the development of atrial fibrillation after an acute coronary syndrome.

BACKGROUND: Evidence linking an elevated white blood cell count (WBCC), a marker of inflammation, to the development of atrial fibrillation (AF) after an acute coronary syndrome (ACS) is limited. We examined the association between WBCC at hospital admission, and changes in WBCC during hospitalization, with the development of new-onset AF during hospitalization for an ACS. METHODS: Development of AF was based on typical ECG changes in a systematic review of hospital medical records. Increase in WBCC was calculated as the difference between maximal WBCC during hospitalization and WBCC at hospital admission. Multiple logistic regression analysis was used to adjust for several potentially confounding demographic and clinical variables in examining the association between WBCC, and changes over time therein, with the occurrence of AF. RESULTS: The median age of study patients (n = 1325) was 60 years, 31.8% were women, and 80.1% were non-Hispanic whites. AF developed in 7.3% of patients with an ACS. Patients who developed AF, as compared with those who did not, had a similar WBCC at admission, but a greater increase in WBCC during hospitalization (6.0 × 109 cell/L vs. 2.7 × 109 cell/L, p < 0.001). After adjusting for several potentially confounding factors, an increase in WBCC was associated with the development of AF. This association was observed in patients with different ACS subtypes, types of treatment received, and according to time of acute symptom onset. CONCLUSION: Increase in the WBCC during hospitalization for an ACS should be further studied as a potentially simple predictor for new-onset AF in these patients.

Clinically significant ventricular arrhythmias and progression of depression and anxiety following an acute coronary syndrome.

BACKGROUND: Depression and anxiety are common and associated with worse clinical outcomes in patients who experience an acute coronary syndrome (ACS). We investigated the association between major ventricular arrhythmias (VAs) with the progression of depression and anxiety among hospital survivors of an ACS. METHODS: Patients were interviewed in hospital and by telephone up to 12 months after hospital discharge. The primary outcome was the presence of moderate/severe symptoms of depression and anxiety defined as a Patient Health Questionnaire (PHQ)-9 score ≥ 10 and a Generalized Anxiety Disorder (GAD)-7 score ≥ 10 at baseline and 1 month and PHQ-2 ≥ 3 and GAD-2 ≥ 3 at 3, 6, and 12 months. We used marginal models to examine the association between major VAs and the symptoms of depression or anxiety over time. RESULTS: The average age of the study population (n = 2074) was 61.1 years, 33.5% were women, and 78.3% were white. VAs developed in 105 patients (5.1%). Symptoms of depression and anxiety were present in 22.2% and 23.5% of patients at baseline, respectively, and declined to 14.1% and 12.6%, respectively, at 1-month post-discharge. VAs were not significantly associated with the progression of symptoms of depression (adjusted relative risk [aRR] = 1.29, 95% confidence interval [CI] = 0.94-1.77) and anxiety (aRR = 1.22, 95% CI = 0.86-1.72), or with change in average scores of PHQ-2 and GAD-2 over time, both before and after risk adjustment. CONCLUSION: The prevalence of symptoms of depression and anxiety was high after an ACS but declined thereafter and may not be associated with the occurrence of major in-hospital VAs.

Decade Long Trends (2001-2011) in the Incidence Rates of Initial Acute Myocardial Infarction.

Despite the magnitude and impact of acute coronary disease, there are limited population-based data in the United States describing relatively recent trends in the incidence rates of acute myocardial infarction (AMI). The objectives of this study were to describe decade long (2001-2011) trends in the incidence rates of initial hospitalized episodes of AMI, with further stratification of these rates by age, sex, and type of AMI, in residents of central Massachusetts hospitalized at 11 area medical centers. The study population consisted of 3,737 adults hospitalized with a first AMI at 11 medical centers in central Massachusetts on a biennial basis between 2001 and 2011. The median age of this study population was 70 years, 57% were men, and 90% were white. Patients hospitalized during the most recent study years (2009/11) were younger, more likely to be men, have more co-morbidities, and less in-hospital complications as compared with those in the earliest study years (2001/03). The overall age-adjusted hospital incidence rates (per 100,000 persons) of initial AMI declined (from 319 to 163), for men (from 422 to 219), women (from 232 to 120), for patients with a ST segment elevation (129 to 56), and for those with an non-ST segment elevation (190 to 107) between 2001 and 2011, respectively. In conclusion, the incidence rates of initial AMI declined appreciably in residents of central Massachusetts who were hospitalized with AMI during the years under study.

Twenty-five year trends (1986-2011) in hospital incidence and case-fatality rates of ventricular tachycardia and ventricular fibrillation complicating acute myocardial infarction.

BACKGROUND: Long-term trends in the incidence rates (IRs) and hospital case-fatality rates (CFRs) of ventricular tachycardia (VT) and ventricular fibrillation (VF) among patients hospitalized with acute myocardial infarction (AMI) have not been recently examined. METHODS: We used data from 11,825 patients hospitalized with AMI at all 11 medical centers in central Massachusetts on a biennial basis between 1986 and 2011. Multivariable adjusted logistic regression modeling was used to examine trends in hospital IRs and CFRs of VT and VF complicating AMI. RESULTS: The median age of the study population was 71 years, 57.9% were men, and 94.7% were white. The hospital IRs declined from 14.3% in 1986/1988 to 10.5% in 2009/2011 for VT and from 8.2% to 1.7% for VF. The in-hospital CFRs declined from 27.7% to 6.9% for VT and from 49.6% to 36.0% for VF between 1986/1988 and 2009/2011, respectively. The IRs of both early (<48 hours) and late VT and VF declined over time, with greater declines in those of late VT and VF. The incidence rates of VT declined similarly for patients with either an ST-segment elevation myocardial infarction (STEMI) or non-STEMI, whereas they only declined in those with VF and a STEMI. CONCLUSIONS: The hospital IRs and CHRs of VT and VF complicating AMI have declined over time, likely because of changes in acute monitoring and treatment practices. Despite these encouraging trends, efforts remain needed to identify patients at risk for these serious ventricular arrhythmias so that preventive and treatment strategies might be implemented as necessary.

Hyperglycemia and risk of ventricular tachycardia among patients hospitalized with acute myocardial infarction.

BACKGROUND: Little is known about the association of hyperglycemia with the development of ventricular tachycardia (VT) in patients hospitalized with acute myocardial infarction (AMI) which we examined in the present study. The objectives of this community-wide observational study were to examine the relation between elevated serum glucose levels at the time of hospital admission for AMI and occurrence of VT, and time of occurrence of VT, during the patient's acute hospitalization. METHODS: We used data from a population-based study of patients hospitalized with AMI at all central Massachusetts medical centers between 2001 and 2011. Hyperglycemia was defined as a serum glucose level ≥ 140 mg/dl at the time of hospital admission. The development of VT was identified from physicians notes and electrocardiographic findings by our trained team of data abstractors. RESULTS: The average age of the study population was 70 years, 58.0% were men, and 92.7% were non-Hispanic whites. The mean and median serum glucose levels at the time of hospital admission were 171.4 mg/dl and 143.0, respectively. Hyperglycemia was present in 51.9% of patients at the time of hospital admission; VT occurred in 652 patients (15.8%), and two-thirds of these episodes occurred during the first 48 h after hospital admission (early VT). After multivariable adjustment, patients with hyperglycemia were at increased risk for developing VT (adjusted OR = 1.48, 95% CI = 1.23-1.78). The presence of hyperglycemia was significantly associated with early (multivariable adjusted OR = 1.39, 95% CI = 1.11-1.73) but not with late VT. Similar associations were observed in patients with and without diabetes and in patients with and without ST-segment elevation AMI. CONCLUSIONS: Efforts should be made to closely monitor and treat patients who develop hyperglycemia, especially early after hospital admission, to reduce their risk of VT.

Barriers to Healthcare Access and to Improvements in Health-Related Quality of Life After an Acute Coronary Syndrome (From TRACE-CORE).

Little is known about how barriers to healthcare access affect health-related quality of life (HRQOL) after an acute coronary syndrome (ACS). In a large cohort of ACS survivors from 6 medical centers in Massachusetts and Georgia enrolled from 2011 to 2013, patients were classified as having any financial barriers, no usual source of care (USOC), or transportation barriers to healthcare based on their questionnaire survey responses. The principal study outcomes included clinically meaningful declines in generic physical and mental HRQOL and in disease-specific HRQOL from 1 to 6 months posthospital discharge. Adjusted relative risks (aRRs) for declines in HRQOL were calculated using Poisson regression models, controlling for several sociodemographic and clinical factors of prognostic importance. In 1,053 ACS survivors, 29.0% had a financial barrier, 14.2% had no USOC, and 8.7% had a transportation barrier. Patients with a financial barrier had greater risks of experiencing a decline in generic physical (aRR 1.48, 95% confidence interval [CI] 1.17, 1.86) and mental (aRR 1.36, 95% CI 1.07, 1.75) HRQOL at 6 months. Patients with 2 or more access barriers had greater risks of decline in generic physical (aRR 1.53, 95% CI 1.20, 1.93) and mental (aRR 1.50, 95% CI 1.17, 1.93) HRQOL compared with those without any healthcare barriers. There was a modest association between lacking a USOC and experiencing a decline in disease-specific HRQOL (aRR 1.46, 95% CI 0.96, 2.22). Financial and other barriers to healthcare access may be associated with clinically meaningful declines in HRQOL after hospital discharge for an ACS.

A nanocomposite prepared from FeOOH and N-doped carbon nanosheets as a peroxidase mimic, and its application to enzymatic sensing of glucose in human urine.

A method is described for the synthesis of a nanocomposite containing FeOOH and N-doped carbon nanosheets. The nanocomposite was synthesized by a hydrothermal method using a Fe3O4/chitosan nanocomposite as the precursor. The nanocomposite displays peroxidase-like activity and catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2. This results in the formation of a blue colored product with an absorption maximum at 652 nm in the UV-vis spectra. Based on these findings, colorimetric assays were worked out for both hydrogen peroxide and glucose. The H2O2 assay works in the 5 to 19 µM concentration range, and the limit of detection is 5 nM. The glucose assay works in the 8 µM to 0.8 mM concentration range and has a 0.2 µM detection limit. The method was successfully applied to the determination of glucose in human urine. Graphical abstract Schematic of the hydrothermal synthesis of a FeOOH/N-doped carbon nanocomposite. It was used to replace peroxidase enzyme for the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in a visual colorimetric test for glucose in human urine.

Trends in Length of Hospital Stay and the Impact on Prognosis of Early Discharge After a First Uncomplicated Acute Myocardial Infarction.

Few studies have examined recent trends in the length of stay (LOS) among patients hospitalized with a first uncomplicated acute myocardial infarction (AMI) and the impact of early hospital discharge on various short-term outcomes in these low-risk patients. We used data from 1,501 residents hospitalized with a first uncomplicated AMI from all central Massachusetts medical centers on a biennial basis between 2001 and 2011. The association between hospital LOS and subsequent hospital readmission or death was examined using logistic regression modeling. The average age of the study population was 63.7 years, 63.0% were men, and 91.4% were non-Hispanic whites. The average hospital LOS declined from 4.1 days in 2001 to 2.9 days in 2011. During the years under study, the average 30-day hospital readmission rate was 11.9%, whereas the 30- and 90-day death rates were 1.5% and 2.9%, respectively. The multivariable adjusted odds ratio of a 30-day hospital readmission (odds ratio [OR] = 0.81, 95% confidence interval [CI] = 0.52 to 1.41), or 30-day (OR = 0.93, 95% CI = 0.29 to 2.98) and 90-day (OR = 0.89, 95% CI = 0.36 to 2.20) death rates were not significantly different between patients who were discharged from central Massachusetts medical centers during the first 2 days as compared with those discharged thereafter. In conclusion, the average LOS in patients with a first uncomplicated AMI declined during the years under study, and early discharge from the hospital at day 2 or sooner of these low-risk patients does not appear to be associated with an increased risk of adverse events post discharge compared with those discharged at a later time.

Underuse of Effective Cardiac Medications Among Women, Middle-Aged Adults, and Racial/Ethnic Minorities With Coronary Artery Disease (from the National Health and Nutrition Examination Survey 2005 to 2014).

Given the proven effectiveness of several cardiac medications for patients with coronary artery disease (CAD), we examined the national use of 4 classes of effective medications, overall and by age, sex, and race/ethnicity in 2005 to 2014. We used data from the National Health and Nutrition Examination Survey, including a self-reported diagnosis of CAD and independently verified medication use. Weighting procedures extrapolated our data to the adult US population with CAD. Analyses included 1,789 US adults aged ≥45 years with a history of CAD. The average age of this population was 68 years; 40% were women and 79% were non-Hispanic whites. In 2005 to 2014, 53.2% (standard error [SE] = 1.5) reported use of angiotensin-converting enzyme inhibitor/angiotensin receptor blockers, 58.5% (SE = 1.5) ß blockers, and 67.2% (SE = 1.4) statins. Two of these medications were used by 64.1% (SE = 1.5) of the study population and all 3 by 29.1% (SE = 1.3). In 2011 to 2014, 68.5% (SE = 2.4) of American adults with a history of CAD reported use of aspirin. The use of statins increased from 63.1% in 2005/2006 to 76.8% in 2013/2014. Adults aged 45 to 64 years old, women, and racial/ethnic minorities had lower use of effective cardiac medications compared with older adults, men, and non-Hispanic whites. In conclusion, the use of statins, but not other medications, has increased over the past 10 years among American adults with previously diagnosed CAD. Continued targeted efforts are needed to increase the receipt of effective cardiac medications among all US adults with CAD, especially those aged 45 to 64 years, women, and racial/ethnic minorities.

Correlates of HIV infection among female sex workers in Vietnam: injection drug use remains a key risk factor.

OBJECTIVE: Women who sell sex and use drugs have dual risks for HIV infection. Despite increasing reports of drug use among female sex workers (FSW) in Vietnam, FSW HIV interventions remain focused mainly on sexual risk reduction. We assessed the impact of drug use and inconsistent condom use on HIV infection among FSW in Vietnam, which few studies have quantified. METHODS: We surveyed 5298 women aged ≥18 years who had sold sex in the past month from ten geographically dispersed provinces. We performed multivariate logistic regression on data from provinces with high (≥10%) or low (<10%) HIV prevalence among FSW. RESULTS: Compared to FSW who never used illicit drugs, the odds of HIV infection among FSW who had ever injected drugs and those who reported non-injection drug use were 3.44 (CI 2.32-5.09) and 1.76 (CI 1.14-2.71), respectively, in high-prevalence provinces. FSW who always used condoms with clients had lower odds of HIV infection than those who did not (AOR=0.71; CI 0.52-0.98). In low-prevalence provinces lifetime injection drug use (AOR 22.05, CI 12.00-40.49), but not non-injecting drug use or inconsistent condom use, was significantly associated with HIV infection. CONCLUSIONS: Because injection drug use and inconsistent condom use were key risk factors for HIV infection in high-prevalence provinces, drug injection risk reduction should be as much a focus of HIV prevention as sexual risk reduction. Where HIV prevalence remains low in FSW, a more general emphasis on harm reduction for all drug users will benefit FSW.

The potential impact of expanding antiretroviral therapy and combination prevention in Vietnam: towards elimination of HIV transmission.

BACKGROUND: Few studies have assessed the effects of antiretroviral therapy (ART) to prevent HIV transmission in Asian HIV epidemics. Vietnam has a concentrated HIV epidemic with the highest prevalence among people who inject drugs. We investigated the impact of expanded HIV testing and counseling (HTC) and early ART, combined with other prevention interventions on HIV transmission. METHODS: A deterministic mathematical model was developed using HIV prevalence trends in Can Tho province, Vietnam. Scenarios included offering periodic HTC and immediate ART with and without targeting subpopulations and examining combined strategies with methadone maintenance therapy and condom use. RESULTS: From 2011 to 2050, maintaining current interventions will incur an estimated 18,115 new HIV infections and will cost US $22.1 million (reference scenario). Annual HTC and immediate treatment, if offered to all adults, will reduce new HIV infections by 14,513 (80%) and will cost US $76.9 million. Annual HTC and immediate treatment offered only to people who inject drugs will reduce new infections by 13,578 (75%) and will cost only US $23.6 million. Annual HTC and immediate treatment for key populations, combined with scale-up of methadone maintenance therapy and condom use, will reduce new infections by 14,723 (81%) with similar costs (US $22.7 million). This combination prevention scenario will reduce the incidence to less than 1 per 100,000 in 14 years and will result in a relative cost saving after 19 years. CONCLUSIONS: Targeted periodic HTC and immediate ART combined with other interventions is cost-effective and could lead to potential elimination of HIV in Can Tho.