The burden of liver disease in Latin America

Liver disease poses a substantial burden in Latin America. This burden is primarily attributed to a high level of alcohol consumption and the increasing prevalence of risk factors associated with metabolic dysfunction-associated steatotic liver disease (MASLD), such as sedentary lifestyles, easy access to ultra-processed foods, obesity, and type 2 diabetes mellitus. These epidemiological trends are cause for concern, especially considering that there are significant challenges in addressing them due to disparities in access to liver disease screening and care. In this article, we aim to provide an overview of the current situation regarding liver disease in Latin America. We also discuss recent multinational proposals designed to address the growing MASLD burden via its integration into existing non-communicable diseases policies, at both local and global levels. Additionally, we emphasize the urgent need to establish effective public health policies that target both MASLD risk factors and excessive alcohol consumption. Furthermore, we discuss the development of liver transplantation programs, areas for improvement in medical education and research capabilities, and how the fostering of extensive collaboration among all stakeholders is crucial for addressing liver disease in the region.

Review article: Current indications and selection criteria for early liver transplantation in severe alcohol-associated hepatitis

BACKGROUND

Alcohol-associated hepatitis (AH) is a severe inflammatory form of alcohol-associated liver disease (ALD) that carries a high mortality rate. Early liver transplantation for severe AH is increasingly available. However, specific criteria for referral and selection remain a subject of debate.

AIMS

To provide a narrative review of the natural history, diagnostic criteria and indications for referral for early liver transplantation for severe AH.

METHODS

We searched PubMed for articles published through August 2023. Key search terms were 'alcoholic hepatitis,' 'alcohol-associated hepatitis,' 'abstinence,' 'alcohol relapse,' and 'liver transplantation.'

RESULTS

Previously, a six-month period of alcohol abstinence was required before patients with ALD were considered for liver transplantation. However, studies in recent years have demonstrated that, among carefully selected patients, patients who received early transplants have much higher survival rates than patients with similarly severe disease who did not undergo transplants (77% vs. 23%). Despite these successes, early liver transplantation remains controversial, as these patients have typically not undergone treatment for alcohol use disorder, with the ensuing risk of returning to alcohol use.

CONCLUSIONS

While early liver transplantation for AH has survival benefits, many patients would not have received treatment for alcohol use disorder. An integrated approach to evaluating candidacy for early liver transplantation is needed.

Incidence of liver cancer in young adults according to the global burden of disease database 2019

OBJECTIVE

The worldwide burden of cancer is increasing in younger populations. However, the epidemiology of primary liver cancer remains understudied in young adults compared to other cancer forms.

METHODS

This study analyzed data from the Global Burden of Disease (GBD) study between 2010 and 2019 to assess the age-standardized incidence, mortality, and disability-adjusted life years (DALYs) associated with primary liver cancer in the young (15-49 y), stratified by region, nation, sociodemographic index, and sex.

RESULTS

The study found a global estimate of 78,299 primary liver cancer cases, 60,602 deaths, and 2.90 million DALYs in the young population. The Western Pacific region exhibited the highest burden in 2019, showing the most significant increase compared to other regions between 2010-2019. More than half of countries worldwide have undergone an increase in primary liver cancer incidence rates in young adults. Around 12.51% of deaths due to primary liver cancer occur in young individuals. Throughout the study period, there was a significant decline in primary liver cancer mortality due to most etiologies, except for metabolic dysfunction-associated steatotic liver disease (MASLD)-attributable primary liver cancer (annual percentage change [APC] +0.87%, 95% confidence interval 0.70-1.05%) and alcohol-attributable primary liver cancer (APC +0.21%, 95% confidence interval 0.01-0.42%). Limitations of the GBD database include reliance on the quality of primary data and possible underestimation of alcohol consumption.

CONCLUSION

Over the past decade, there has been a marked increase in the burden of primary liver cancer, especially that originating from steatotic liver disease. This trend calls for the development of urgent and comprehensive strategies to mitigate this rising burden globally.

Alcohol-related liver disease: A global perspective

Alcohol-associated liver disease (ALD) represents one of the deadliest yet preventable consequences of excessive alcohol use. It represents 5.1 % of the global burden of disease, mainly involving the productive-age population (15-44 years) and leading to an increased mortality risk from traffic road injuries, suicide, violence, cardiovascular disease, neoplasms, and liver disease, among others, accounting for 5.3 % of global deaths. Daily alcohol consumption, binge drinking (BD), and heavy episodic drinking (HED) are the patterns associated with a higher risk of developing ALD. The escalating global burden of ALD, even exceeding what was predicted, is the result of a complex interaction between the lack of public policies that regulate alcohol consumption, low awareness of the scope of the disease, late referral to specialists, underuse of available medications, insufficient funds allocated to ALD research, and non-predictable events such as the COVID-19 pandemic, where increases of up to 477 % in online alcohol sales were registered in the United States. Early diagnosis, referral, and treatment are pivotal to achieving the therapeutic goal in patients with alcohol use disorder (AUD) and ALD, where complete alcohol abstinence and prevention of alcohol relapse are expected to enhance overall survival. This can be achieved through a combination of cognitive behavioral, motivational enhancement and pharmacological therapy. Furthermore, the appropriate use of available pharmacological therapy and implementation of public policies that comprehensively address this disease will make a real difference.

Global and regional burden of alcohol-associated liver disease and alcohol use disorder in the elderly

Background & Aims

Alcohol-associated liver diseases (ALDs) and alcohol use disorder (AUD) pose a global health risk. AUD is underrecognized in the elderly, and the burden of AUD complications, including ALD, may increase with aging populations and rising alcohol intake. However, there is a lack of epidemiological evidence on AUD and ALD in the elderly.

Methods

Using the Global Burden of Disease Study 2019, we analyzed the prevalence, mortality, disability-adjusted life years (DALYs), age-standardized rates (ASRs), and temporal change from 2000 to 2019 of ALD and AUD in the overall population and the elderly (65-89 years). The findings were categorized by sex, region, nation, and sociodemographic index.

Results

The prevalence rates of ALD in the elderly were higher than those in adolescents and young adults, whereas AUD levels were lower than those in adolescents and young adults. In 2019, there were 9.39 million cases (8.69% of cases in the overall population) of AUD, 3.23 million cases (21.8% of cases in the overall population) of alcohol-associated cirrhosis, and 68,468 cases (51.27% of cases in the overall population) of liver cancer from alcohol among the elderly. ASRs of the prevalence of ALD and AUD in the elderly increased in most regions; on the contrary, ASRs of death and DALYs decreased in most regions. Nevertheless, ASRs of death and DALYs from liver cancer from alcohol increased in many areas.

Conclusions

Our findings highlighted the increased prevalence of ALD in the elderly, with a burden of AUD comparable with that in the overall population. Public health strategies on ALD and AUD targeting the elderly are urgently needed.

Impact and implications

The burden of alcohol-associated liver disease (ALD) and alcohol use disorder (AUD) is increasing. Advances in healthcare and education have resulted in a remarkable spike in life expectancy and a consequential population aging. Nevertheless, little is known about the epidemiology of ALD and AUD in the elderly. Our study indicates the increasing burden of ALD and AUD in the elderly population, necessitating early detection, intervention, and tailored care to the unique needs and complexities faced by older individuals grappling with these conditions.

Racial and ethnic disparities in alcohol-associated liver disease in the United States: A systematic review and meta-analysis

BACKGROUND

Alcohol-associated liver disease (ALD), encompassing alcohol-associated hepatitis and alcohol-associated cirrhosis, is rising in the United States. Racial and ethnic disparities are evident within ALD; however, the precise nature of these disparities is poorly defined.

METHODS

We conducted a search of the PubMed/MEDLINE and EMBASE databases to identify studies published from inception through September 2023 that reported ALD incidence, prevalence, and mortality within the United States, stratified by race and ethnicity. We calculated pooled prevalence and incidence by race and ethnicity, including risk ratios and ORs for ALD pooled prevalence and alcohol-associated hepatitis/alcohol-associated cirrhosis pooled proportions, and OR for ALD mortality using the DerSimonian and Laird method for random-effect models.

RESULTS

We identified 25 relevant studies (16 for quantitative meta-analysis), comprising 76,867,544 patients. ALD prevalence was highest in Hispanic (4.5%), followed by White (3.1%) and Black (1.4%) individuals. Pooled risk ratios of ALD prevalence were 1.64 (95% CI: 1.12-2.39) for Hispanic and 0.59 (95% CI: 0.35-0.87) for Black compared to White individuals. Mortality among those with ALD did not significantly differ between White and Hispanic (OR: 1.54, 95% CI: 0.9-2.5; I2=0%), Black (OR: 1.2, 95% CI: 0.8-1.6; I2=0%), or Native American (OR: 2.41, 95% CI: 0.9-2.9) individuals, while there was a significant difference between White and Asian (OR: 0.1; 95% CI: 0.03-0.5) individuals. Most data were cross-sectional and assessed to be of poor or fair quality.

CONCLUSIONS

Differences were observed in ALD epidemiology, including higher prevalence among Hispanic and lower prevalence among Black individuals, although there were smaller differences in ALD mortality. Differences in ALD prevalence and prognosis remain poorly defined based on existing data, highlighting a need for higher-quality epidemiological studies in this area.

Association between public health policies on alcohol and worldwide cancer, liver disease and cardiovascular disease outcomes

BACKGROUND & AIMS

The long-term impact of alcohol-related public health policies (PHPs) on disease burden is unclear. We aimed to assess the association between alcohol-related PHPs and alcohol-related health consequences.

METHODS

We conducted an ecological multi-national study including 169 countries. We collected data on alcohol-related PHPs from the WHO Global Information System of Alcohol and Health 2010. Data on alcohol-related health consequences between 2010-2019 were obtained from the Global Burden of Disease database. We classified PHPs into five items, including criteria for low, moderate, and strong PHP establishment. We estimated an alcohol preparedness index (API) using multiple correspondence analysis (0 lowest and 100 highest establishment). We estimated an incidence rate ratio (IRR) for outcomes according to API using adjusted multilevel generalized linear models with a Poisson family distribution.

RESULTS

The median API in the 169 countries was 54 [IQR 34.9-76.8]. The API was inversely associated with alcohol use disorder (AUD) prevalence (IRR 0.13; 95% CI 0.03-0.60; p = 0.010), alcohol-associated liver disease (ALD) mortality (IRR 0.14; 95% CI 0.03-0.79; p = 0.025), mortality due to neoplasms (IRR 0.09; 95% CI 0.02-0.40; p = 0.002), alcohol-attributable hepatocellular carcinoma (HCC) (IRR 0.13; 95% CI 0.02-0.65; p = 0.014), and cardiovascular diseases (IRR 0.09; 95% CI 0.02-0.41; p = 0.002). The highest associations were observed in the Americas, Africa, and Europe. These associations became stronger over time, and AUD prevalence was significantly lower after 2 years, while ALD mortality and alcohol-attributable HCC incidence decreased after 4 and 8 years from baseline API assessment, respectively (p <0.05).

CONCLUSIONS

The API is a valuable instrument to quantify the robustness of alcohol-related PHP establishment. Lower AUD prevalence and lower mortality related to ALD, neoplasms, alcohol-attributable HCC, and cardiovascular diseases were observed in countries with a higher API. Our results encourage the development and strengthening of alcohol-related policies worldwide.

IMPACT AND IMPLICATIONS

We first developed an alcohol preparedness index, an instrument to assess the existence of alcohol-related public policies for each country. We then evaluated the long-term association of the country's alcohol preparedness index in 2010 with the burden of chronic liver disease, hepatocellular carcinoma, other neoplasms, and cardiovascular disease. The strengthening of alcohol-related public health policies could impact long-term mortality rates from cardiovascular disease, neoplasms, and liver disease. These conditions are the main contributors to the global burden of disease related to alcohol use. Over time, this association has not only persisted but also grown stronger. Our results expand the preliminary evidence regarding the importance of public health policies in controlling alcohol-related health consequences.

Racial and Ethnic Disparities in Liver Transplantation for Alcohol-associated Liver Diseases in the United States

BACKGROUND

Emerging data suggest disparities exist in liver transplantation (LT) for alcohol-associated liver disease (ALD). As the incidence of ALD increases, we aimed to characterize recent trends in ALD LT frequency and outcomes, including racial and ethnic disparities.

METHODS

Using United Network for Organ Sharing/Organ Procurement and Transplantation Network data (2015 through 2021), we evaluated LT frequency, waitlist mortality, and graft survival among US adults with ALD (alcohol-associated hepatitis [AH] and alcohol-associated cirrhosis [AAC]) stratified by race and ethnicity. We used adjusted competing-risk regression analysis to evaluate waitlist outcomes, Kaplan-Meier analysis to illustrate graft survival, and Cox proportional hazards modeling to identify factors associated with graft survival.

RESULTS

There were 1211 AH and 26 526 AAC new LT waitlist additions, with 970 AH and 15 522 AAC LTs performed. Compared with non-Hispanic White patients (NHWs) with AAC, higher hazards of waitlist death were observed for Hispanic (subdistribution hazard ratio [SHR] = 1.23, 95% confidence interval [CI]: 1.16-1.32), Asian (SHR = 1.22, 95% CI:1. 01-1.47), and American Indian/Alaskan Native (SHR = 1.42, 95% CI: 1.15-1.76) candidates. Similarly, significantly higher graft failures were observed in non-Hispanic Black (HR = 1.32, 95% CI: 1.09-1.61) and American Indian/Alaskan Native (HR = 1.65, 95% CI: 1.15-2.38) patients with AAC than NHWs. We did not observe differences in waitlist or post-LT outcomes by race or ethnicity in AH, although analyses were limited by small subgroups.

CONCLUSIONS

Significant racial and ethnic disparities exist for ALD LT frequency and outcomes in the United States. Compared with NHWs, racial and ethnic minorities with AAC experience increased risk of waitlist mortality and graft failure. Efforts are needed to identify determinants for LT disparities in ALD that can inform intervention strategies.

The intersection between alcohol-related liver disease and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD) are the leading causes of chronic liver disease worldwide. NAFLD and ALD share pathophysiological, histological and genetic features and both alcohol and metabolic dysfunction coexist as aetiological factors in many patients with hepatic steatosis. A diagnosis of NAFLD requires the exclusion of significant alcohol consumption and other causes of liver disease. However, data suggest that significant alcohol consumption is often under-reported in patients classified as having NAFLD and that alcohol and metabolic factors interact to exacerbate the progression of liver disease. In this Review, we analyse existing data on the interaction between alcohol consumption and metabolic syndrome as well as the overlapping features and differences in the pathogenesis of ALD and NAFLD. We also discuss the clinical implications of the coexistence of alcohol consumption, of any degree, in patients with evidence of metabolic derangement as well as the use of alcohol biomarkers to detect alcohol intake. Finally, we summarize the evolving nomenclature of fatty liver disease and describe a recent proposal to classify patients at the intersection of NAFLD and ALD. We propose that, regardless of the presumed aetiology, patients with fatty liver disease should be evaluated for both metabolic syndrome and alcohol consumption to enable better prognostication and a personalized medicine approach.

Active alcohol consumption is associated with acute-on-chronic liver failure in Hispanic patients

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a severe clinical entity associated with elevated short-term mortality. We aimed to characterize patients with decompensated cirrhosis according to presence of ACLF, their association with active alcohol intake, and long-term survival in Latin America.

METHODS

Retrospective cohort study of decompensated cirrhotic in three Chilean university centers (2017-2019). ACLF was diagnosed according EASL-CLIF criteria. We assessed survival using competing-risk and time-to-event analyses. We evaluated the time to death using accelerated failure time (AFT) models.

RESULTS

We included 320 patients, median age of 65.3±11.7 years old, and 48.4% were women. 92 (28.7%) patients met ACLF criteria (ACLF-1: 29.3%, ACLF-2: 27.1%, and ACLF-3: 43.4%). The most common precipitants were infections (39.1%), and the leading organ failure was kidney (59.8%). Active alcohol consumption was frequent (27.7%), even in patients with a prior diagnosis of non-alcoholic fatty liver disease (NAFLD) (16.2%). Ninety-two (28.7%) patients had ACLF (ACLF-1: 8.4%, ACLF-2: 7.8%, and ACLF-3: 12.5%). ACLF patients had a higher MELD-Na score at admission (27 [22-31] versus 16 [12-21], p<0.0001), a higher frequency of alcohol-associated liver disease (36.7% versus 24.9%, p=0.039), and a more frequent active alcohol intake (37.2% versus 23.8%, p=0.019). In a multivariate model, ACLF was associated with higher mortality (subdistribution hazard ratio 1.735, 95%CI: 1.153-2.609; p<0.008). In the AFT models, the presence of ACLF during hospitalization correlated with a shorter time to death: ACLF-1 shortens the time to death by 4.7 times (time ratio [TR] 0.214, 95%CI: 0.075-0.615; p<0.004), ACLF-2 by 4.4 times (TR 0.224, 95%CI: 0.070-0.713; p<0.011), and ACLF-3 by 37 times (TR 0.027, 95%CI: 0.006-0.129; p<0.001).

CONCLUSIONS

Patients with decompensated cirrhosis and ACLF exhibited a high frequency ofactive alcohol consumption. Patients with ACLF showed higher mortality and shorter time todeath than those without ACLF.

MELD 3.0 adequately predicts mortality and renal replacement therapy requirements in patients with alcohol-associated hepatitis

Background & Aims

Model for End-Stage Liver Disease (MELD) score better predicts mortality in alcohol-associated hepatitis (AH) but could underestimate severity in women and malnourished patients. Using a global cohort, we assessed the ability of the MELD 3.0 score to predict short-term mortality in AH.

Methods

This was a retrospective cohort study of patients admitted to hospital with AH from 2009 to 2019. The main outcome was all-cause 30-day mortality. We compared the AUC using DeLong's method and also performed a time-dependent AUC with competing risks analysis.

Results

A total of 2,124 patients were included from 28 centres from 10 countries on three continents (median age 47.2 ± 11.2 years, 29.9% women, 71.3% with underlying cirrhosis). The median MELD 3.0 score at admission was 25 (20-33), with an estimated survival of 73.7% at 30 days. The MELD 3.0 score had a better performance in predicting 30-day mortality (AUC:0.761, 95%CI:0.732-0.791) compared with MELD sodium (MELD-Na; AUC: 0.744, 95% CI: 0.713-0.775; p = 0.042) and Maddrey's discriminant function (mDF) (AUC: 0.724, 95% CI: 0.691-0.757; p = 0.013). However, MELD 3.0 did not perform better than traditional MELD (AUC: 0.753, 95% CI: 0.723-0.783; p = 0.300) and Age-Bilirubin-International Normalised Ratio-Creatinine (ABIC) (AUC:0.757, 95% CI: 0.727-0.788; p = 0.765). These results were consistent in competing-risk analysis, where MELD 3.0 (AUC: 0.757, 95% CI: 0.724-0.790) predicted better 30-day mortality compared with MELD-Na (AUC: 0.739, 95% CI: 0.708-0.770; p = 0.028) and mDF (AUC:0.717, 95% CI: 0.687-0.748; p = 0.042). The MELD 3.0 score was significantly better in predicting renal replacement therapy requirements during admission compared with the other scores (AUC: 0.844, 95% CI: 0.805-0.883).

Conclusions

MELD 3.0 demonstrated better performance compared with MELD-Na and mDF in predicting 30-day and 90-day mortality, and was the best predictor of renal replacement therapy requirements during admission for AH. However, further prospective studies are needed to validate its extensive use in AH.

Impact and implications

Severe AH has high short-term mortality. The establishment of treatments and liver transplantation depends on mortality prediction. We evaluated the performance of the new MELD 3.0 score to predict short-term mortality in AH in a large global cohort. MELD 3.0 performed better in predicting 30- and 90-day mortality compared with MELD-Na and mDF, but was similar to MELD and ABIC scores. MELD 3.0 was the best predictor of renal replacement therapy requirements. Thus, further prospective studies are needed to support the wide use of MELD 3.0 in AH.

Inpatient Hepatology Consultation

Cirrhosis is the end-stage of chronic liver disease and constitutes a leading cause of potential years of working life lost, especially in the Americas and Europe. Its natural history is characterized by an asymptomatic phase called compensated cirrhosis, followed by a rapidly progressive phase characterized by liver-related complications termed decompensated cirrhosis. Complications could be related to portal hypertension and/or liver dysfunction, including ascites, portal hypertensive gastrointestinal bleeding, encephalopathy, and jaundice. This review will discuss some of the most important precipitants of hepatic decompensation, including acute variceal bleeding, spontaneous bacterial peritonitis, and hepatic encephalopathy.

High prevalence of SARS-CoV-2 detection and prolonged viral shedding in stools: A systematic review and cohort study

Objectives

Methods

Results

Conclusions

Phantosmia May Predict Long-Term Measurable Olfactory Dysfunction After COVID-19

Objectives

Persistent olfactory dysfunction (OD) after 6 months caused by SARS‐CoV‐2 infection has been reported with a variable prevalence worldwide. This study aimed to determine the prevalence of long‐term OD and identify predisposing factors.

Methods

A prospective cohort study was conducted on 100 adults with COVID‐19. Olfactory function was assessed with the University of Pennsylvania Smell Identification Test and a symptom survey at the onset of disease and 30 days later. Patients with persistent quantitative OD at the second assessment were reevaluated after 1 year. Demographic variables, symptoms, and the degree of smell loss were analyzed.

Results

Participants included 100 patients. The mean age was 42.2 ± 15.6 years, 55 (55%) were female, and 56 (56%) were outpatients. Baseline smell loss was identified in 75/100 (75%) patients, decreasing to 39/95 (40%) after 1 month, and persisting in 29 patients after 1 year. Phantosmia at baseline was the only risk factor identified for persistent OD after 1 year (relative risk 2.51; 95% confidence interval 1.53–4.12; p < 0.001). Regardless of the outcome in smell function, a significant decline in olfaction was associated with the presence of phantosmia at 1 month (β = −12.39; 95% CI −19.82 to −4.95; p < 0.01).

Conclusions

SARS‐CoV‐2 (2019–2020 variants) produced a highly frequent OD that persisted in 29% of the patients after 1 year. The presence of phantosmia at baseline and 1 month was associated with a worse evolution, but phantosmia may interfere with the performance in an identification smell test. A longer follow‐up is required in these patients.

Level of Evidence

2 Laryngoscope, 2022

Alcohol Consumption: Medical Implications, the Liver and Beyond

Alcohol consumption represents a major factor of morbidity and mortality, with a wide range of adverse medical implications that practically affect every organ system. It is the fifth major cause of deaths in men and women and causes up to 139 million disability-adjusted life years. Solid evidence places the risk as undoubtedly correlated to the length of time and amount of alcohol consumption. While alcohol-related liver disease represents one of the most studied and well-known consequences of alcohol use, the term itself embodies a wide spectrum of progressive disease stages that are responsible for almost half of the liver-related mortality worldwide. We discuss the staged alcohol-related fatty liver, alcohol-related steatohepatitis and, finally, fibrosis and cirrhosis, which ultimately may end up in a hepatocellular carcinoma. Other comorbidities such as acute and chronic pancreatitis; central nervous system; cardiovascular, respiratory and endocrine system; renal disease; urological pathologies; type 2 diabetes mellitus and even infectious diseases are reviewed in their relation to alcohol consumption. This article reviews the impact of alcohol use on different systems and organs, summarizing available evidence regarding its medical implications. It examines current basic and clinical data regarding mechanisms to highlight factors and processes that may be targetable to improve patient outcomes. Although alcohol use is a part of many cultural and social practices, as healthcare providers we must identify populations at high risk of alcohol abuse, educate patients about the potential alcohol-related harm and provide appropriate treatment.

Frailty and reduced gait speed are independently related to mortality of cirrhotic patients in long-term follow-up

INTRODUCTION AND OBJECTIVES

Frailty is characterized by a poor restoration of homeostasis after a stressor event. Although it is not usually diagnosed, it has been associated with decreased survival in cirrhotic patients. We aimed to evaluate the impact of frailty and decreased gait speed over survival in cirrhotic patients at long-term follow-up.

MATERIALS AND METHODS

We included stable cirrhotic patients Child-Pugh B-C or MELD ≥12, ≥50 years old. We performed a clinical evaluation, anthropometry, and laboratory tests. Frailty was diagnosed using Fried Frailty Index. We evaluated survival at a 4-year follow-up.

RESULTS

We included 126 patients; mean age 64±8.3 years, median MELD-Na 15[12-17], median follow-up was 881 [349-1277] days. The main etiology was MAFLD (31.4%). Frailty was diagnosed in 65.1% of patients. There were no significant differences in baseline characteristics per frailty condition. Mortality was higher in frail patients than non-frail patients (68.2% versus 20.6% at 48 months, respectively; p-value <0.001). The mean gait speed in frail and non-frail patients was 0.86±0.3m/s and 1.16±0.2m/s, respectively (p-value <0.001). Interestingly, 26.9% of patients presented a reduced gait speed (≤0.8m/s). Patients with decreased gait speed also had higher mortality than patients with normal gait speed (79.9% versus 40.8%, respectively; p-value <0.001). A multivariate-adjusted model showed that decreased gait speed (HR=3.27, 95%CI:1.74-6.14; p<0.001) and frailty (HR=4.24, 95%CI:1.89-9.51; p<0.001) were associated with mortality.

CONCLUSIONS

Frailty is independently associated with decreased survival at long-term follow-up. Reduced gait speed is strongly associated with mortality and could be a surrogate marker of frailty in clinical practice.

NAFLD: Challenges and opportunities to address the public health problem in Latin America

Non-alcoholic fatty liver disease (NAFLD) is reaching epidemic proportions worldwide. Collectively, Latin American countries have some of the highest obesity rates in the world and the fastest-growing prevalence of type 2 diabetes mellitus (T2DM). Since obesity and T2DM are intrinsically linked with NAFLD, epidemiological projections are worrisome. In addition to this adverse epidemiological setting, the region of Latin America faces unique challenges and obstacles to addressing the growing burden of NAFLD. In this article, on the occasion of the International NASH Day on June 10, 2021, we describe the main challenges and opportunities to improve care of people living with NAFLD in Latin America. Among the major challenges to be tackled are: lack of disease awareness, limited educational opportunities for healthcare personnel and general public, health system fragmentation, and lack of effective strategies for the prevention and effective treatment of NAFLD and common comorbidities, namely obesity and T2DM. Wide dissemination of current concepts on NAFLD, and extensive collaboration between scientific societies, governments, non-governmental organizations, pharmaceutical industry, and other stakeholders is urgently needed to advance the NAFLD public health policies agenda that allows us to address this disease with a whole of society approach.

Colorectal adenomas and MAFLD: a cross-sectional study in a hispanic screening cohort

Aims: Prior evidence demonstrates an association between non-alcoholic fatty liver disease (NAFLD) and colorectal adenomas (CRA) risk. However, information using the new definition of the disease [i.e., metabolic dysfunction-associated fatty liver disease (MAFLD)] is scarce. We aimed to assess the relationship between MAFLD and CRA risk. Methods: We conducted a cross-sectional study including patients from three university centers in Chile who underwent a colonoscopy for colorectal cancer screening and abdominal imaging study. We obtained sociodemographic and clinical data, and we performed univariate and multivariable regression analyses. Results: In total, 895 patients were included; 42% were male, the mean age was 59.9 ± 9.3 years, and 37.8% (338) had CRA. Patients harboring polyps were predominantly males (48.2% vs. 38.2%, P = 0.002), older (61.6 ± 8.7 years vs. 58.9 ± 9.5 years, P < 0.001), and exhibited a higher body weight than controls [75 (66-88) kg vs. 72 (63-82.3) kg, P = 0.002]. Fifty-six percent of patients showed hepatic steatosis in imaging studies and 54.4% met MAFLD diagnostic criteria. The adenoma detection rate was higher in the MAFLD group compared to controls (46.4% vs. 27.5%, P < 0.001). In the multivariable analysis, MAFLD was significantly associated with the presence of CRA (odds ratio = 2.32; 95%CI: 1.68-3.19, P < 0.0001). There were no statistically significant differences of histopathological characteristics of the adenomas according to the presence of MAFLD. Conclusion: The present study shows that, in Chilean Hispanic subjects, MAFLD is associated with an increased risk of CRA. This information may be useful to design specific screening colonoscopy recommendations in MAFLD patients.

Identification of optimal therapeutic window for steroid use in severe alcohol-associated hepatitis: A worldwide study

BACKGROUND & AIMS

Corticosteroids are the only effective therapy for severe alcohol-associated hepatitis (AH), defined by a model for end-stage liver disease (MELD) score >20. However, there are patients who may be too sick to benefit from therapy. Herein, we aimed to identify the range of MELD scores within which steroids are effective for AH.

METHODS

We performed a retrospective, international multicenter cohort study across 4 continents, including 3,380 adults with a clinical and/or histological diagnosis of AH. The main outcome was mortality at 30 days. We used a discrete-time survival analysis model, and MELD cut-offs were established using the transform-the-endpoints method.

RESULTS

In our cohort, median age was 49 (40-56) years, 76.5% were male, and 79% had underlying cirrhosis. Median MELD at admission was 24 (19-29). Survival was 88% (87-89) at 30 days, 77% (76-78) at 90 days, and 72% (72-74) at 180 days. A total of 1,225 patients received corticosteroids. In an adjusted-survival-model, corticosteroid use decreased 30-day mortality by 41% (hazard ratio [HR] 0.59; 0.47-0.74; p <0.001). Steroids only improved survival in patients with MELD scores between 21 (HR 0.61; 0.39-0.95; p = 0.027) and 51 (HR 0.72; 0.52-0.99; p = 0.041). The maximum effect of corticosteroid treatment (21-30% survival benefit) was observed with MELD scores between 25 (HR 0.58; 0.42-0.77; p <0.001) and 39 (HR 0.57; 0.41-0.79; p <0.001). No corticosteroid benefit was seen in patients with MELD >51. The type of corticosteroids used (prednisone, prednisolone, or methylprednisolone) was not associated with survival benefit (p = 0.247).

CONCLUSION

Corticosteroids improve 30-day survival only among patients with severe AH, especially with MELD scores between 25 and 39.

LAY SUMMARY

Alcohol-associated hepatitis is a condition where the liver is severely inflamed as a result of excess alcohol use. It is associated with high mortality and it is not clear whether the most commonly used treatments (corticosteroids) are effective, particularly in patients with very severe liver disease. In this worldwide study, the use of corticosteroids was associated with increased 30-day, but not 90- or 180-day, survival. The maximal benefit was observed in patients with an MELD score (a marker of severity of liver disease; higher scores signify worse disease) between 25-39. However, this benefit was lost in patients with the most severe liver disease (MELD score higher than 51).

Impact of Public Health Policies on Alcohol-Associated Liver Disease in Latin America: An Ecological Multinational Study

BACKGROUND AND AIMS

Alcohol-associated liver disease (ALD) is the leading cause of liver-related mortality in Latin America, yet the impact of public health policies (PHP) on liver disease is unknown. We aimed to assess the association between alcohol PHP and deaths due to ALD in Latin American countries.

APPROACH AND RESULTS

We performed an ecological multinational study including 20 countries in Latin America (628,466,088 inhabitants). We obtained country-level sociodemographic information from the World Bank Open Data source. Alcohol-related PHP data for countries were obtained from the World Health Organization Global Information System of Alcohol and Health. We constructed generalized linear models to assess the association between the number of PHP (in 2010) and health outcomes (in 2016). In Latin America, the prevalence of obesity was 27% and 26.1% among male and female populations, respectively. The estimated alcohol per capita consumption among the population at 15 years old or older was 6.8 L of pure alcohol (5.6 recorded and 1.2 unrecorded). The overall prevalence of alcohol use disorders (AUD) was 4.9%. ALD was the main cause of cirrhosis in 64.7% of male and 40.0% of female populations. A total of 19 (95%) countries have at least one alcohol-related PHP on alcohol. The most frequent PHP were limiting drinking age (95%), tax regulations (90%), drunk-driving policies and countermeasures (90%), and government monitoring systems and community support (90%). A higher number of PHP was associated with a lower ALD mortality (PR, 0.76; 95% CI, 0.61-0.93; P = 0.009), lower AUD prevalence (PR, 0.80; 95% CI, 0.65-0.99; P = 0.045), and lower alcohol-attributable road traffic deaths (PR, 0.81; 95% CI, 0.65-1.00; P = 0.051).

CONCLUSIONS

Our study indicates that in Latin America, countries with higher number of PHP have lower mortality due to ALD, lower prevalence of AUD, and lower alcohol-attributable road traffic mortality.

COVID-19 and Indirect Liver Injury: A Narrative Synthesis of the Evidence

The liver is frequently affected by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. The most common manifestations are mildly elevated alanine aminotransferase and aspartate aminotransferase, with a prevalence of 16-53% among patients. Cases with severe coronavirus disease 2019 (COVID-19) seem to have higher rates of acute liver dysfunction, and the presence of abnormal liver tests at admission signifies a higher risk of severe disease during hospitalization. Patients with chronic liver diseases also have a higher risk of severe disease and mortality (mainly seen in patients with metabolic-associated fatty liver disease). Several pathways of damage have been proposed in the liver involvement of COVID-19 patients; although, the end-cause is most likely multifactorial. Abnormal liver tests have been attributed to the expression of angiotensin-converting enzyme 2 receptors in SARS-CoV-2 infection. This enzyme is expressed widely in cholangiocytes and less in hepatocytes. Other factors attributed to liver damage include drug-induced liver injury, uncontrolled release of proinflammatory molecules ("cytokine storm"), pneumonia-associated hypoxia, and direct damage by the infection. Hepatic steatosis, vascular thrombosis, fibrosis, and inflammatory features (including Kupffer cell hyperplasia) are the most common liver histopathological findings in deceased COVID-19 patients, suggesting important indirect mechanisms of liver damage. In this translational medicine-based narrative review, we summarize the current data on the possible indirect mechanisms involved in liver damage due to COVID-19, the histopathological findings, and the impact of these mechanisms in patients with chronic liver disease.

Adding Two Antimicrobial Glasses to an Endodontic Sealer to Prevent Bacterial Root Canal Reinfection: An In Vivo Pilot Study in Dogs

Current endodontic procedures continue to be unsuccessful for completely removing pathogens present inside the root canal system, which can lead to recurrent infections. In this study, we aimed to assess the antimicrobial capacity and tissue response of two inorganic bactericidal additives incorporated into a paste root canal sealer on contaminated root dentin in vivo. An experimental study was performed in 30 teeth of five Beagle dogs. After inducing microbiological contamination, root canal systems were treated by randomly incorporating one of two antimicrobial additives into a commercial epoxy-amine resin sealer (AH Plus), i.e., G3T glass-ceramic (n = 10) and ZnO-enriched glass (n = 10); 10 samples were randomized as a control group. After having sacrificed the animals, microbiological, radiological, and histological analyses were performed, which were complemented with an in vitro bactericidal test and characterization by field emission scanning electron microscopy. The tested groups demonstrated a non-significant microbiological reduction in the postmortem periapical index values between the control group and the bactericidal glass-ceramic group (p = 0.885), and between the control group and the ZnO-enriched glass group (p = 0.169). The histological results showed low values of inflammatory infiltrate, and a healing pattern characterized by fibrosis in 44.4% of the G3T glass-ceramic and 60.0% of ZnO-enriched glass. Bactericidal glassy additives incorporated in this root canal sealer are safe and effective in bacterial reduction.

Management of Biliopancreatic Limb Bleeding after Roux-en-Y Gastric Bypass: A Case Report

The Roux-en-Y gastric bypass is one of the most extensive surgical treatments for obesity. The treatment of upper gastrointestinal bleeding after Roux-en-Y gastric bypass is complex due to the difficulty of accessing the excluded gastric antrum and duodenal bulb. There is no consensus regarding the management of this complication. While various techniques have been described to access the biliopancreatic limb, double-balloon enteroscopy is the most commonly used. If double-balloon enteroscopy is unavailable, a pediatric colonoscope may be used as an alternative; however, its use in such cases has not been described. We report the case of a 50-year-old male patient who underwent gastric bypass 13 years ago and was admitted for a second episode of upper gastrointestinal bleeding. The initial approach using upper endoscopy, colonoscopy, and abdominal computed tomography angiography did not reveal the cause of gastrointestinal hemorrhage; therefore, an endoscopic study of the biliopancreatic limb was performed using a pediatric colonoscope. A Forrest Ib ulcer was found in the duodenal bulb, and endoscopic therapy was administered. The evolution was found to be satisfactory.

[Teaching innovation in an undergraduate theoretical medicine course]

BACKGROUND

The School of Medicine of the Pontificia Universidad Católica de Chile implemented diverse curricular changes addressing teaching challenges, including those related to generational diversity.

AIM

To describe the implementation and results of curricular innovation in the Theoretic Gastroenterology Course (CTG) imparted between 2008 and 2020.

MATERIALS AND METHODS

The new teaching methods consisted in the implementation of interactive sessions, research conferences, video-recorded classes, and a learning management/assessment platform. An assessment of the learning model was implemented. As bibliographic material we incorporated self-instructive material and the CTG manual was re-edited. We registered the course syllabi, evaluation surveys, and final grades.

RESULTS

Students dedicated more time to attend the course, from 12.2 hours before to 18 hours after the implementation of video lessons (p < 0.05). They reported improvements in the areas "Feedback" (from 6.2 to 6.6, on a scale of 1 to 7; p < 0.05) and "Grades" (from 6.3 to 6.4; p < 0.05), after implementing a learning model assessment. The score for "Information sources" increased from 6.5 to 6.6 after the re-edition of the manual (p < 0.05). The final grades were similar or significantly higher than the average grades of all the theoretical courses imparted in the same period.

CONCLUSIONS

The CTG underwent a series of curricular modifications, allowing for a rapid adaptation to extremely dynamic academic conditions.

[Analysis of the organ allocation system for liver transplantation in Chile]

BACKGROUND

In Chile, organ allocation for liver transplantation (LT) in adults is prioritized according to the MELD-Na score. Exceptions such as Hepatocellular Carcinoma (HCC) and other non-HCC exceptions receive a score called Operational MELD score.

AIM

To evaluate the effectiveness of the MELD-Na score and the operational MELD score as a prioritization system for LT in Chile.

MATERIAL AND METHODS

Retrospective analysis of the waiting list (WL) of adult candidates (≥ 15 years) for elective LT in Chile from 2011 to 2017. The probability of leaving the WL, defined by death or contraindication for LT was compared in three groups: 1) Cirrhotic patients prioritized according to their real MELD-Na score (CPM), 2) HCC and 3) other non-HCC exceptions.

RESULTS

We analyzed 730 candidates for LT, with a median age of 57 years, 431 (56%) were men. In the study period, 352 LT were performed (48%). The annual exit rate was significantly higher in the CPM group (45.5%) compared to HCC (33.1%) and non-HCC (29.3%), (p < 0.001). Post LT survival was 86% at 1 year and 85% at 5 years, without significant differences between groups. In the CPM group, post-transplant survival was significantly lower (p < 0.05) in patients with MELD-Na ≥ 30 at transplant (81% per year) compared to patients with patients with MELD-Na < 30 (91% per year).

CONCLUSIONS

MELD-Na score can discriminate very well patients who have a higher risk of death in the short and medium term. However, the assignment of operational scores for situations of exception produces inequities in the allocation of organs for LT and must therefore be carefully adjusted.

[Current situation of pediatric liver transplantation in Chile. Inequities associated with the MELD/PELD prioritization system]

BACKGROUND

The Chilean allocation system for liver transplantation (LT) uses the MELD/PELD score to prioritize candidates on the waiting list.

AIM

To assess if the Chilean allocation system for LT is equitable for pediatric candidates compared to their adult counterparts.

MATERIAL AND METHODS

We used the Public Health Institute's registry between October 2011 and December 2017. We analyzed candidates with chronic hepatic diseases listed for LT. The primary outcome was the cadaveric liver transplantation (CLT) rate. Secondary outcomes were death or disease progression in the waiting list and living donor liver transplant (LDLT) rate.

RESULTS

We analyzed 122 pediatric and 735 adult candidates. Forty one percent of pediatric candidates obtained a CLT compared to 48% of adults (p = NS). Among patients aged under two years of age, the access to CLT on the waiting list there was 28% of CLT, compared to 48% in adults (p = 0.001). Fifty-seven percent of candidates aged under two years were listed for cholestatic diseases, obtaining a CLT in 18% and requiring a LDLT in 49%. The median time in the waiting list for CLT was 5.9 months in pediatric candidates and 5.1 in adults, while the median time to death in the waiting list was 2.8 and 5.6 months, respectively. The mortality rate at one year in candidates under two years old was 38.1% compared to 32.5% in adults.

CONCLUSIONS

Pediatric candidates with chronic liver diseases, especially under two years of age, have greater access difficulties to CLT than adults. Half of the pediatric candidates die on the waiting list before three months. The mortality among candidates under two years of age in the waiting list is excessively high.

High prevalence of hepatic steatosis and vascular thrombosis in COVID-19: A systematic review and meta-analysis of autopsy data

BACKGROUND

Coronavirus disease 2019 (COVID-19) disease can frequently affect the liver. Data on hepatic histopathological findings in COVID-19 is scarce.

AIM

To characterize hepatic pathological findings in patients with COVID-19.

METHODS

We conducted a systematic review with meta-analysis registered on PROSPERO (CRD42020192813), following PRISMA guidelines. Eligible trials were those including patients of any age and COVID-19 diagnosis based on a molecular test. Histopathological reports from deceased COVID-19 patients undergoing autopsy or liver biopsy were reviewed. Articles including less than ten patients were excluded. Proportions were pooled using random-effects models. Q statistic and I² were used to assess heterogeneity and levels of evidence, respectively.

RESULTS

We identified 18 studies from 7 countries; all were case reports and case series from autopsies. All the patients were over 15 years old, and 67.2% were male. We performed a meta-analysis of 5 studies, including 116 patients. Pooled prevalence estimates of liver histopathological findings were hepatic steatosis 55.1% [95% confidence interval (CI): 46.2-63.8], congestion of hepatic sinuses 34.7% (95%CI: 7.9-68.4), vascular thrombosis 29.4% (95%CI: 0.4-87.2), fibrosis 20.5% (95%CI: 0.6-57.9), Kupffer cell hyperplasia 13.5% (95%CI: 0.6-54.3), portal inflammation 13.2% (95%CI: 0.1-48.8), and lobular inflammation 11.6% (95%CI: 0.3-35.7). We also identified the presence of venous outflow obstruction, phlebosclerosis of the portal vein, herniated portal vein, periportal abnormal vessels, hemophagocytosis, and necrosis.

CONCLUSION

We found a high prevalence of hepatic steatosis and vascular thrombosis as major histological liver features. Other frequent findings included portal and lobular inflammation and Kupffer cell hyperplasia or proliferation. Further studies are needed to establish the mechanisms and implications of these findings.

[Protocolized referral to endoscopy and Helicobacter pylori detected in stools aimed to decrease endoscopy waiting lists]

Background Chile has one of the highest mortality rates by gastric cancer (GC) worldwide. Primary prevention of GC and detection of pre-neoplastic and early neoplastic lesions should be a national priority. Aim To assess the impact of the protocolization of endoscopy referral and the use of H. pylori stool antigen test (HPSA) in the management of dyspepsia to decrease the waiting list for endoscopy and increase the detection of gastric pre-neoplastic and early neoplastic lesions. Material and Methods We included all patients referred to the Endoscopy Unit of a regional hospital, from January 2015 to December 2017. We also included patients with known pre-neoplastic lesions and all those with first degree relatives with GC. We implemented protocols for referral of patients with dyspepsia considering the use of HPSA test, prioritizing to endoscopy those with a higher risk of GC. Results A total of 4,641 endoscopies and 2,631 HPSA tests were carried out. After the adoption of these protocols, we observed a 52% decrease in the waiting time for endoscopy. The GC detection rate in this period was 1.8 to 3.1 cases per 100 endoscopies. After the adoption of the protocols, we observed a significant increase in early GC detection rate (from none in 2015 to 13% in 2017, p = 0.03). Conclusions The protocolization of the referral for endoscopy associated with widespread use of HPSA test in the management of patients with dyspepsia, are successful strategies to decrease waiting lists for endoscopy and optimize the detection rate of pre-neoplastic lesions and early GC.

[Experience of continuing online education in gastroenterology for non specialist medical doctors]

BACKGROUND

Continuing education is essential for health professions and online courses can be a good way for professional development.

AIM

To describe the experience with online courses for continuing education in hepatology and gastroenterology and to analyze their educational impact.

MATERIAL AND METHODS

A three years' experience in courses on liver diseases and digestive tract is described. Their curricular design, methodology, and the educational impact was analyzed using the four levels of the Kirkpatrick's model.

RESULTS

On average, there were 321 students per course (2015-2017). 94% were Chilean and 6% from abroad (20 countries). In the educational impact analysis, in level 1 "reaction": 93% said that the course fulfilled their expectations and 92% would recommend it. In level 2 "learning": 42% approved the courses. Level 3 "behavior" was not evaluated and level 4 "organizational change" highlighted that the traditional face-to-face continuing education model of Chilean Gastroenterology Society (SChG) changed to full distance model in these three courses, with 1284 students from South America, Asia and Europe, in a 3-years-period. Additionally, these programs were included in the Medical Society of Santiago (SMS) continuing education agenda.

CONCLUSIONS

The alliance between the SMS and the SChG generated on line courses that meet the educational needs of physicians and medical students, with excellent results and student perception.

In vitro biofilm formation on different ceramic biomaterial surfaces: Coating with two bactericidal glasses

OBJECTIVES

To compare biofilm formation on the surface of different ceramic biomaterials to be used in implant dentistry.

METHODS

In vitro biofilm formation was investigated from mixtures of standard reference strains of Streptococcus oralis, Veillonella parvula, Actinomyces naeslundii, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Sterile ceramic calcium hydroxyapatite discs (HA) as control, sterile Al₂O₃/Ce-TZP nanocomposite sandblasted discs (material A1) and sterile Al₂O₃/Ce-TZP nanocomposite sandblasted discs and coated with two types of antimicrobial glasses (materials A2 and A3) were used. Biofilms were grown on the four surfaces and evaluated after 12, 24, 48 and 72 h of incubation. Biofilms were examined by confocal laser scanning microscopy (CLSM). In addition, counts of live bacterial cells of the target species A. actinomycetemcomitans, F. nucleatum and P. gingivalis were calculated by quantitative polymerase chain reaction (qPCR) combined with propidium monoazide (PMA). For data analysis, bacterial counts were compared with a multivariate general lineal model.

RESULTS

Using CLSM, cell vitality decreased in A2 and A3. With qPCR-PMA, significant differences in vitality were observed forA. actinomycetemcomitans in A3 after 48 and 72 h of incubation. With respect to the development of the biofilms, a significant increase in counts on HA and materials A1 and A2 was observed for A. actinomycetemcomitans and F. nucleatum. Conversely, for P. gingivalis, no differences were found for HA and materials A1 and A2.

SIGNIFICANCE

Differences in biofilm formation were detected among the different tested materials. The ceramic material A3 has an effect on the vitality of A. actinomycetemcomitans growing in an in vitro biofilm model.

“Residents get no… satisfaction” a problem to face during internal medicine rotations: development and psychometric properties of the IMPRINT-15

Clinical rotations are an essential part of Internal Medicine (IM) residency programmes, where curricular objectives are carried out. To our knowledge, there are no validated instruments to assess IM clinical rotations. Our objective was to develop an instrument for residents to assess the quality of clinical rotations in an IM residency programme, and to test the psychometric properties of the instrument. A mixed methodology was used, including qualitative and quantitative phases. Items were proposed by a group of experts based on previously identified residency needs, followed by a quantitative phase to generate consensus among educators and residents to define which items would be included in the instrument (Delphi panel). After generating the instrument, psychometric tests were performed to assess construct validity (factor analysis) and reliability (Raykov’s reliability coefficient). We obtained a 15-item instrument after two Delphi rounds: Internal Medicine Program Instrument 15-items (IMPRINT-15). Sixty-two residents answered 428 surveys using a Likert scale during 7 months (response rate 98.9%). The median score was 4.3 (IQR 3.9–4.7) (scale from 1 to 5). The factor analysis showed two domains in the clinical rotation assessment: (1) teaching and care activities; (2) evaluation and feedback. The instrument is reliable with Raykov’s reliability coefficient of 0.86. Also, Raykov’s reliability coefficient for the domains were 0.89 and 0.83, respectively. The IMPRINT-15 instrument is a bi-dimensional, valid and reliable questionnaire to evaluate the perceived quality by residents of the IM clinical rotations. Also, it constitutes the first validated instrument in this field worldwide.

New hosts for the mite Ornithonyssus bursa in Argentina

The mite Ornithonyssus bursa (Berlese) (Mesostigmata: Macronyssidae) is considered a poultry pest causing important infestations in chickens and it is considered a potential vector of arbovirus. Despite being considered a common parasite in wild birds, there is scarce published information about its potential hosts and effects on them. Here we present new bird hosts for O. bursa, assess the presence of Alphavirus, Flavivirus and Bunyavirus in mites from three host species, and discuss its potential impact on wild bird populations. We found O. bursa infecting five raptor and six passerine wild bird species. For nine of these species, this is the first record of infection by O. bursa. Although all analysed mites were negative for the examined arboviruses, the small sample size of mites does not allow further conclusions at the present moment. Because of the general nature of this ectoparasite, its presence in migratory long dispersal and endangered bird species, and the seropositivity for arboviruses in some of the species studied here, we consider it critical to assess the role of O. bursa and other ectoparasites as vectors and reservoirs of pathogens and as potential deleterious agents in wild bird populations.

[Development of MEDUC-PG14 survey to assess postgraduate teaching in medical specialties]

BACKGROUND

Feedback is one of the most important tools to improve teaching in medical education.

AIM

To develop an instrument to assess the performance of clinical postgraduate teachers in medical specialties.

MATERIAL AND METHODS

A qualitative methodology consisting in interviews and focus-groups followed by a quantitative methodology to generate consensus, was employed. After generating the instrument, psychometric tests were performed to assess the construct validity (factor analysis) and reliability (Cronbach’s alpha).

RESULTS

Experts in medical education, teachers and residents of a medical school participated in interviews and focus groups. With this information, 26 categories (79 items) were proposed and reduced to 14 items (Likert scale 1-5) by an expert’s Delphi panel, generating the MEDUC-PG14 survey, which was answered by 123 residents from different programs of medical specialties. Construct validity was carried out. Factor analysis showed three domains: Teaching and evaluation, respectful behavior towards patients and health care team, and providing feedback. The global score was 4.46 ± 0.94 (89% of the maximum). One teachers’ strength, as evaluated by their residents was “respectful behavior” with 4.85 ± 0.42 (97% of the maximum). “Providing feedback” obtained 4.09 ± 1.0 points (81.8% of the maximum). MEDUC-PG14 survey had a Cronbach’s alpha coefficient of 0.947.

CONCLUSIONS

MEDUC-PG14 survey is a useful and reliable guide for teacher evaluation in medical specialty programs. Also provides feedback to improve educational skills of postgraduate clinical teachers.

Glass-(nAg, nCu) biocide coatings on ceramic oxide substrates

The present work was focused on obtaining biocide coatings constituted by a glassy soda-lime matrix containing silver or copper nanoparticles on ceramic (alumina and zirconia based) substrates. Both glassy coatings showed a high biocide activity against Gram-, Gram+ bacteria and yeast, reducing cell numbers more than three logarithms. Silver nanoparticles had a significantly higher biocide activity than copper nanoparticles, since the lixiviation levels required to reduce cell numbers more than 3 logarithms was of almost 1-2 µg/cm(2) in the case of silver nanoparticles, and 10-15 µg/cm(2) for the copper nanoparticles.

The enigmatic autoimmune response in endemic pemphigus foliaceus

Endemic pemphigus foliaceus, known as Fogo Selvagem (FS) in Brazil, is a disease characterized by subcorneal blisters and IgG4 anti-dermoglein 1 (Dsg1) autoantibodies. Epidemiological studies of FS strongly an environmental etiology. A 15-year surveillance of the Limao Verde Amerindian reservation in Brazil has uncovered information on the transition of the autoimmune response from the pre-clinical stage to disease state. This incubation time may evolve over several years. The serological markers of the pre-clinical state of FS are IgM anti-Dsg1, IgE and non-IgG4 autoantibodies against Dsg1. The disease stage of FS is characterized by the rise of pathogenic IgG4 anti-Dsg1 autoantibodies. In this review, the authors reviewed the literature on the relevance of the humoral autoimmune response of FS as well as the possible environmental triggers of anti-Dsg1 autoantibody formation. Based on epidemiological observations, the authors hypothesize that the pathogenic IgG4 response in FS may be triggered by hematophagous insect bites.

Cocirculation of Rio Negro Virus (RNV) and Pixuna Virus (PIXV) in Tucumán province, Argentina

Venezuelan equine encephalitis complex includes viruses considered emerging pathogens for humans and animals in the Americas. Two members of this complex have been detected previously in Argentina: Rio Negro Virus (RNV), detected in mosquitoes from Chaco province and rodents from Formosa province, and Pixuna Virus (PIXV), detected in mosquitoes from Chaco province. To carry out surveillance studies in other parts of the country, detection of a 195-bp fragment of alphaviruses by RT-nested PCR was performed in mosquito samples from San Miguel de Tucumán city. Four pools resulted positive and three were sequenced. Two amplicons grouped with RNV and one with PIXV. This is the first report of viral activity of members of the Venezuelan equine encephalitis complex in north-eastern Argentina.

Epitaxial growth of tungsten nanoparticles on alumina and spinel surfaces

Isolated tungsten nanoparticles (α-W and β-W phase) were synthesized and epitaxially grown on alumina and spinel particle surfaces with an average tungsten size of ≤20 nm for a low tungsten content (of ≤1.5 vol%). Using tungsten (VI) ethoxide alcoholic solutions, tungsten trioxide hydrated precursors were attached to a ceramic grains surface as a nanoparticle coating. High-resolution transmission electron microscopy (HRTEM) micrographs showed epitaxial interfaces between alumina, spinel and metallic tungsten. This epitaxial growth is assumed to be due to the effect of water vapour on the sublimation of ortho-tungstic acid during the reduction process in a hydrogen atmosphere. The planes involved in the epitaxy were found to be [Formula: see text] and [Formula: see text].