Humoral immune response in people living with HIV after administration of SARS-CoV-2 vaccine CoronaVac or BNT162b2 or CoronaVac/BNT162b2 booster sequence: A cross-sectional study.

BACKGROUND: The evidence of SARS-CoV-2 vaccine effectiveness in people living with HIV (PLWH) is limited. This study evaluated the humoral immune response to CoronaVac™ (virus inactivated) and BNT162b2 (mRNA- based) vaccines in PLWH and HIV-negative controls, with and without a booster sequence. METHODS: We conducted a cross-sectional study on PLWH and HIV-negative controls who received CoronaVac or BNT162b2, with a subgroup receiving a CoronaVac/BNT162b2 booster. Blood samples were collected 4-6 months after primary vaccination and tested for anti-SARS-CoV-2 protein S (aSAb) and neutralizing antibodies (NtAb) using validated assays. Immune response was evaluated by age, sex, previous COVID-19 history, and CD4 + cell count. FINDINGS: One hundred and eighty nine participants were enrolled with 161 (85%) being PLWH. Among participants without previous known COVID-19, median aSAb levels were significantly lower in PLWH who received CoronaVac compared to BNT162b2 (32 U/mL vs. 587 U/mL, p < 0.001), with similar results in HIV-negative controls. NtAb presence was also significantly lower after CoronaVac compared to BNT162b2 (30% vs. 93%, p < 0.001). The booster sequence group showed a significant increase in aSAb titers in both PLWH and HIV-negative controls (from 33 U/ml to 2500 U/ml, p < 0.001), and NtAb positivity increased from 20% to 95 % in PLWH, and 27% to 100% in HIV-negative controls. Prior COVID-19 led to significantly higher post-vaccine antibody titers particularly in the BNT162b2 group. PLWH with CD4 + count < 200 cells/mL showed a weaker immune response to both vaccines. INTERPRETATION: CoronaVac resulted in a weaker immune response in both PLWH and HIV-negative controls compared to BNT162b2, particularly in immunosuppressed PLWH without prior COVID-19. Hybrid immunity and heterologous booster vaccination increased antibody levels. FUNDING: Local funding.

Exercise-based intervention as a nonsurgical treatment for patients with carpal instability: A case series.

BACKGROUND: Although the important roles of proprioception and neuromuscular control in carpal instabilities under laboratory conditions have been recognized, only a few studies have translated this knowledge into a routine clinical practice. PURPOSE: This study aimed to evaluate the results of a personalized rehabilitation in patients with carpal instability on functionality and pain intensity. STUDY DESIGN: This was a case series study. METHODS: This case series included 39 adults (mean age: 38.2 ± 14.0 years; 16/23 females/males) diagnosed with carpal instability (radial or ulnar) with indication for orthopedic treatment. The disabilities of the arm, shoulder, and hand questionnaire was used to assess upper limb functionality. Pain perception was assessed using a visual analog scale. Exercise-based physiotherapy interventions were performed according to the clinical needs of the patients for at least 6 weeks (2-3 sessions per week). For the treatment of radial instability (n = 13), strengthening exercises of the abductor pollicis longus, extensor carpi radialis longus, flexor carpi radialis, and pronator quadratus muscles were prescribed. For the treatment of ulnar instability (n = 24), extensor carpi ulnaris and pronator quadratus were trained. All patients underwent proprioceptive training in open kinetic chain and closed kinetic chain, as well as strengthening of the unaffected hand. Changes before and after treatment were compared using the nonparametric Wilcoxon signed rank test. RESULTS: A significant improvement with a large effect size in disabilities of the arm, shoulder, and hand (P < .001; d = 2.9) and visual analog scale (P < .001; d = 3.2) scores were obtained after treatment. Moreover, the changes were greater than the minimal clinically important difference of 10.8 and 1.4, respectively. Similar results were found when patients with radial instability and ulnar instability were analyzed separately. CONCLUSIONS: Personalized training with specific proprioception and strengthening exercises produces improvements in functionality and pain perception in our cohort of people with carpal instability. These results highlight the importance of multicomponent exercise in the treatment of wrist instability. Future randomized clinical trials should further investigate the effectiveness of this protocol.

Hypervirulent Strains of Neisseria meningitidis and Clinical Manifestations in Children With Invasive Meningococcal Disease.

BACKGROUND: Hypervirulent clonal complex (cc) have been associated with higher incidence and case fatality rate of invasive meningococcal disease (IMD). The aim of this study was to describe the clinical manifestations of the hypervirulent cc of meningococcus in children. METHODS: Retrospective study in patients hospitalized by IMD microbiologically confirmed at three children's tertiary health care centers in Santiago, Chile, between 2010 and 2018. Demographic, clinical information and determination of the cc and factor H binding protein (fHbp) alleles were performed. RESULTS: In total 93 cases were evaluated, sequence typing was available for 91 cases, and 87 (95.6%) had a cc assigned; 63.7% were MenW and 31.8% MenB. The median age was 9 months, 67% were male and 18.7% had any comorbidity. A 26.4% presented neurological deficit, 25.3% petechiae and 20% diarrhea. Sixty-seven percent were admitted to the pediatric intensive care unit (PICU) and the case fatality rate was 9.9%. Regarding cc and fHbp alleles, ST11, ST41/44 and allele 22 were the most frequently identified, with 63.7%, 19.8% and 72.5%, respectively. We found statistically significant differences between the cc and presence of petechiae, diagnosis of meningococcemia plus meningitis, admission and days in PICU and advanced support. Allele 22 for fHbp was associated with the absence of petechiae, low suspicion of IMD, less diagnosis of meningitis+meningococcemia, PICU admission, advanced support and adrenal insufficiency. CONCLUSION: Epidemiological and microbiological surveillance of IMD should integrate clinical and laboratory components, including molecular and genetic characterization, to enrich the dynamic understanding of the clinical evolution of IMD.

Intrahospital supervised exercise training improves survival rate among hypertensive patients with COVID-19.

Among the people most affected by coronavirus disease 2019 (COVID-19) are those suffering from hypertension (HTN). However, pharmacological therapies for HTN are ineffective against COVID-19 progression and severity. It has been proposed that exercise training (EX) could be used as post-COVID treatment, which does not rule out the possible effects during hospitalization for COVID-19. Therefore, we aimed to determine the impact of supervised EX on HTN patients with COVID-19 during hospitalization. Among a total of 1,508 hospitalized patients with COVID-19 (confirmed by PCR), 439 subjects were classified as having HTN and were divided into two groups: EX (n = 201) and control (n = 238) groups. EX (3-4 times/wk during all hospitalizations) consisted of aerobic exercises (15-45 min; i.e., walking); breathing exercises (10-15 min) (i.e., diaphragmatic breathing, pursed-lip breathing, active abdominal contraction); and musculoskeletal exercises (8-10 sets of 12-15 repetitions/wk; lifting dumbbells, standing up and sitting, lumbar stabilization). Our data revealed that the EX (clinician: patient, 1:1 ratio) intervention was able to improve survival rates among controlled HTN patients with COVID-19 during their hospitalization when compared with the control group (chi-squared: 4.83; hazard ratio: 1.8; 95% CI: 1.117 to 2.899; P = 0.027). Multivariate logistic regression analysis revealed that EX was a prognostic marker (odds ratio: 0.449; 95% CI: 0.230-0.874; P = 0.018) along with sex and invasive and noninvasive mechanical ventilation. Our data showed that an intrahospital supervised EX program reduced the mortality rate among patients with HTN suffering from COVID-19 during their hospitalization.NEW & NOTEWORTHY In the present study, we found that exercise training improves the survival rate in hypertensive patients with COVID-19 during their hospitalization period. Our results provide strong evidence for the therapeutic efficacy of exercise training as a feasible approach to improving the outcomes of patients with COVID-19 who suffer from hypertension during their hospitalization.

How accurate are radiography and computed tomography in the diagnosis of COVID-19?-A Bayesian approach.

Background: The role of radiology in patients with clinical suspicion of COVID-19 is evolving with scientific evidence, but there are differences in opinion on when and how the technique should be used for clinical diagnosis. Purpose: To estimate the pre-test and post-test probability that a patient has COVID-19 in the event of a positive and/or negative result from chest X-ray and chest computed tomography (CT) radiological studies, comparing with those of real time polymerase chain reaction (RT-PCR) tests. Methods: The literature on the sensitivity and specificity of the chest X-ray, chest CT, and RT-PCR was reviewed. Based on these reported data, the likelihood ratios (LR) were estimated and the pre-test probabilities were related to the post-test probabilities after positive or negative results. Results: The chest X-ray has only a confirmatory value in cases of high suspicion. Chest CT analyses showed that when it is used as a general study, it has almost confirmatory value under high clinical suspicion. A chest CT classified with CO-RADS ≥ 4 has almost a diagnostic certainty of COVID-19 even with moderate or low clinical presumptions, and the CO-RADS 5 classification is almost pathognomonic before any clinical presumption. To rule out COVID-19 completely is only possible in very low clinical assumptions with negative RT-PCR and/or CT. Conclusions: Chest X-ray and especially CT are fast studies that have the capacity to report high probability of COVID-19, being a real contribution to the concept of "probable case" and allowing support to be installed in an early and timely manner.

[Vitamin D deficiency/insufficiency on healthy infants receiving standard supplementation]. / Deficiencia e insuficiencia de vitamina D en lactantes sanos recibiendo suplementación estándar.

Vitamin D (VD) is essential for calcium and phosphorus metabolism. Its deficiency can cause rickets. In Chile, newborns receive 400UI/day supplementation from the first day of age until the first year. OBJECTIVE: To describe the VD plasma levels in healthy infants who received supplementation and secondarily to correlate this with seasonality and nutritional status. SUBJECTS AND METHOD: Cross sectional study. Infants on exclusive or mixed breastfeeding, with monthly pediatric checkups recei ving 400 UI VD supplementation were evaluated, measuring VD plasma levels at 6 months of age, weight, and length, and their nutritional status was classified according to the WHO growth referen ces (weight/age and weight/length). The VD cut-off concentration values were < 20 ng/ml, 21- 29 ng/ ml, and ≥ 30 ng/ml considered as deficiency, insufficiency, and sufficiency, respectively. RESULTS: 40 infants were studied, 40% had insufficient levels and 40% presented deficiency. Season and nutritio nal status were variables significantly related to lower VD values (Winter-Spring p = 0.007; at risk of malnutrition p = 0.038). CONCLUSIONS: The population who received supplementation presented a high frequency of VD deficiency and insufficiency which increases during winter and spring and in subjects at risk of malnutrition.

Physiological asymmetry in uterine artery blood flow during the first trimester of pregnancy: New insights from a quantitative assessment using Pulsed-wave color Doppler and M-mode color power angio imaging.

INTRODUCTION: This study aimed to quantify uterine artery (UtA) blood flow and its hemodynamic components throughout the first trimester of pregnancy using Doppler ultrasound. METHODS: Cross-sectional cohort study involving women undergoing a routine ultrasound scan between 5 and 13 weeks' gestation. UtA blood flow was measured using Pulsed-wave Color Doppler to assess blood flow velocity across the cardiac cycle and M-mode Color Power Angio imaging to assess UtA diameter. A formula was applied to calculate systolic and diastolic blood flow volumes according to Poiseuille's equation. RESULTS: A total of 330 women with a single viable first-trimester pregnancy agreed to participate in this study. A stepwise increase in total UtA blood flow was observed during the first trimester, with significant increases at 7, 8, and 11 weeks. No significant differences in blood flow were observed between right and left UtAs. However, there was a statistically significant difference when comparing the UtA based on higher and lower blood flow, with a mean ± SD of 64.4% ± 10.5% through the former (p < 0.001). The increase in the UtA blood flow was secondary to an increase in the blood flow rate between 5 and 10 weeks. A significant increase in UtA diameter was only identified from 11 weeks onwards. DISCUSSION: UtA blood flow in the first trimester is asymmetrical, at a constant ratio of ≈2:1. An interpretive model of the possible origin of this pattern during early pregnancy is proposed.

First-trimester miscarriage rate decreases with hydralazine therapy in pregnancies with early uterine vascular insufficiency: a cohort study.

BACKGROUND: Miscarriage is the most frequent cause of pregnancy loss, affecting 15-20% of clinically recognized pregnancies. Early uterine vascular insufficiency (EUVI), defined as abnormal uterine artery (UA) Doppler impedance indices in early pregnancy, is present in two-thirds of pregnancies ending in miscarriage after embryonic cardiac activity has been detected. There is currently no available therapy for reducing the risk of miscarriage in these cases. OBJECTIVE: To determine whether vasodilator therapy with hydralazine can reduce abnormally high UA impedance indices and miscarriage rates in pregnancies with EUVI when administered from before 9 weeks' gestation until completing 13 weeks' gestation. METHODS: A total of 253 consecutive singleton pregnancies with a live embryo and scanned before 9 weeks' gestation were included in the study. Ninety-two pregnancies (36.3%) were classified as having EUVI. Hydralazine was administered in daily doses of 50 mg, starting 24-36 h after the initial diagnosis of EUVI and continuing throughout the first trimester. The miscarriage rate in the hydralazine-treated EUVI group was compared with the one observed in our previously reported untreated cohort and the pregnancies with EUVI that declined treatment with hydralazine. RESULTS: The miscarriage rate among the hydralazine-treated EUVI group was significantly lower than the previously reported untreated cohort (7.8% versus 26.2%, p = .003; odds ratio (OR) = 4.3, 95% confidence interval (CI) = 1.6-11.9). In 15 untreated pregnancies with EUVI, the miscarriage rate was similar to that of the previously reported untreated cohort (26.7% versus 26.2%; p = .603) and higher than the hydralazine-treated group (26.7% versus 7.8%, p = .05; OR = 4.4, 95% CI = 1.1-18.2). CONCLUSIONS: Hydralazine therapy in pregnancies with EUVI was associated with a significant decrease in the rate of miscarriage. We suggest a sequence of events leading to a higher risk of miscarriage in pregnancies with EUVI and propose a potential mechanism through which hydralazine may reduce this risk.

[Redefining the gold standard for aortic valve replacement: Minimally invasive with accelerated recovery]. / Redefiniendo el estándar de oro para el reemplazo valvular aórtico: mínimamente invasivo y recuperación acelerada.

BACKGROUND: Despite being introduced 20 years ago minimally invasive aortic valve replacement is only performed routinely in a minority of patients world-wide. AIM: To report the operative outcome of minimally invasive aortic valve replacement done through a partial upper sternotomy. PATIENTS AND METHODS: Retrospective analysis of data recorded prospectively of 450 consecutive patients with a median age of 66 years (59% males) who had a minimally invasive aortic replacement. RESULTS: 79% of patients had aortic stenosis. Cross clamp/cardiopulmonary bypass times (median) were 56 and 68 minutes respectively. Conversion to full sternotomy was required in 2.6% of patients, reoperation for bleeding in 2.9%. 1.6% suffered a stroke and 19% postoperative atrial fibrillation. 0.9% required a permanent pacemaker. Postoperative mortality was 0.9%. Median postoperative hospital stay was six days. CONCLUSIONS: Minimally invasive aortic valve replacement can be performed with satisfactory results.

Major Histocompatibility Complex Class I-Related Chain A (MICA) Allelic Variants Associate With Susceptibility and Prognosis of Gastric Cancer.

Gastric cancer (GC) is the fifth most prevalent type of cancer worldwide. Gastric tumor cells express MICA protein, a ligand to NKG2D receptor that triggers natural killer (NK) cells effector functions for early tumor elimination. MICA gene is highly polymorphic, thus originating alleles that encode protein variants with a controversial role in cancer. The main goal of this work was to study MICA gene polymorphisms and their relationship with the susceptibility and prognosis of GC. Fifty patients with GC and 50 healthy volunteers were included in this study. MICA alleles were identified using Sanger sequencing methods. The analysis of MICA gene sequence revealed 13 MICA sequences and 5 MICA-short tandem repeats (STR) alleles in the studied cohorts We identified MICA*002 (*A9) as the most frequent allele in both, patients and controls, followed by MICA*008 allele (*A5.1). MICA*009/049 allele was significantly associated with increased risk of GC (OR: 5.11 [95% CI: 1.39-18.74], p = 0.014). The analysis of MICA-STR alleles revealed a higher frequency of MICA*A5 in healthy individuals than GC patients (OR = 0.34 [95% CI: 0.12-0.98], p = 0.046). Survival analysis after gastrectomy showed that patients with MICA*002/002 or MICA*002/004 alleles had significantly higher survival rates than those patients bearing MICA*002/008 (p = 0.014) or MICA*002/009 (MICA*002/049) alleles (p = 0.040). The presence of threonine in the position MICA-181 (MICA*009/049 allele) was more frequent in GC patients than controls (p = 0.023). Molecular analysis of MICA-181 showed that the presence of threonine provides greater mobility to the protein than arginine in the same position (MICA*004), which could explain, at least in part, some immune evasion mechanisms developed by the tumor. In conclusion, our findings suggest that the study of MICA alleles is crucial to search for new therapeutic approaches and may be useful for the evaluation of risk and prognosis of GC and personalized therapy.

Redefiniendo el estándar de oro para el reemplazo valvular aórtico: mínimamente invasivo y recuperación acelerada / Redefining the gold standard for aortic valve replacement: minimally invasive with accelerated recovery

Background: Despite being introduced 20 years ago minimally invasive aortic valve replacement is only performed routinely in a minority of patients world-wide. Aim: To report the operative outcome of minimally invasive aortic valve replacement done through a partial upper sternotomy. Patients and Methods: Retrospective analysis of data recorded prospectively of 450 consecutive patients with a median age of 66 years (59% males) who had a minimally invasive aortic replacement. Results: 79% of patients had aortic stenosis. Cross clamp/cardiopulmonary bypass times (median) were 56 and 68 minutes respectively. Conversion to full sternotomy was required in 2.6% of patients, reoperation for bleeding in 2.9%. 1.6% suffered a stroke and 19% postoperative atrial fibrillation. 0.9% required a permanent pacemaker. Postoperative mortality was 0.9%. Median postoperative hospital stay was six days. Conclusions: Minimally invasive aortic valve replacement can be performed with satisfactory results.

COVID-19 in Chile: The usefulness of simple epidemic models in practice. / COVID-19 en Chile: la utilidad de los modelos epidémicos simples en la práctica.

OBJECTIVES: The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. METHODS: We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time framea basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. RESULTS: The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curves asymmetry in Santiago. CONCLUSIONS: The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

OBJETIVOS: El objetivo general ha sido describir y evaluar el valor predictivo de tres modelos durante el desarrollo de la epidemia COVID-19 en Chile, aportando conocimiento para la toma de decisiones en salud. MÉTODOS: Desarrollamos tres modelos a lo largo de la epidemia: un modelo discreto para predecir a corto tiempo la máxima carga sobre el sistema de salud, un modelo básico SEIR (susceptibles-expuestos-infectados-removidos) con ecuaciones discretas; un modelo SEIR estocástico con método de Montecarlo; y un modelo de tipo Gompertz para la Región Metropolitana (Santiago). RESULTADOS: El modelo de máxima carga potencial ha sido útil durante todo el seguimiento de la epidemia proporcionando una cota superior para el número de casos, la ocupación de unidades de cuidados intensivos y el número de fallecidos. Los modelos SEIR determinístico y estocástico tuvieron gran utilidad en la predicción del ascenso de los casos, el máximo y el inicio del descenso de casos, perdiendo utilidad en la situación actual por el reclutamiento asincrónico de casos en las regiones y la persistencia de una endemia alta. El modelo de Gompertz ha tenido un mejor ajuste en el descenso ya que esta captura mejor la asimetría de la curva epidémica en Santiago. CONCLUSIONES: Los modelos han demostrado gran utilidad en el seguimiento de la epidemia en Chile, con distintos objetivos en distintas etapas de la epidemia. Han complementado los indicadores empíricos como casos reportados, letalidad, fallecimientos y otros, permitiendo predecir situaciones de interés y visualizar la conducta a corto y largo plazo de esta pandemia a nivel local.

Role and effects of zinc supplementation in HIV-infected patients with immunovirological discordance: A randomized, double blind, case control study.

INTRODUCTION: It has been estimated that between 15% and 18% of patients who start antiretroviral therapy (ART) do not achieve a successful immune recovery despite complete virological suppression. In the literature this phenomenom is known as poor immune recovery or immunovirological discordance (IVD). Zinc has an immunomodulatory role associated with T lymphocytes and its supplementation could enhance immune recovery. OBJECTIVE: To determine if zinc supplementation on IVD patients prevents immune failure after 12 months of supplementation. Secondary objectives were to determine serum zinc levels in HIV patients with and without IVD and the frequency of hypozincemia in discordant patients. METHOD: We reviewed the historical record of patients under care at Arriarán Foundation. Following inclusion criteria were defined: 1) age ≥ 18 years, 2) standard ART (three effective drugs) for at least 18 months, 3) virologically suppressed for 12 months, 3) persistence of CD4 count ≤200 cells/mm3 and/or increase ≤ 80 cells/mm3 after one year of viral undetectability. A control group was assigned paired 1:1 by sex, age (± 2 years) that did achieved an increase of CD4> 350 cells/ mm3. In both groups plasma zinc levels were determined. In a later phase, patients with IVD were randomized to receive zinc (15 mg daily) versus placebo. Patients were followed for 12 months with CD4 count, viral load and zinc levels determinations every 4-6 months. RESULTS: A total of 80 patients, 40 patients with IVD criteria and 40 controls were included. 92.5% were men, and age average was 47.5 years. The median baseline CD4 was 189 cells/mm3 (71-258) in the cases vs. 552.5 cells/ mm3 (317-400) in the control group with a median increase at the end of the study of 39 cell/mm3 and 19 cell/mm3 respectively. There was no difference in baseline plasma zinc levels between both groups (81.7 + 18.1 in cases versus 86.2 + 11.0 in controls). In the 40 patients with IVD, the median absolute increase in CD4 after annual zinc supplementation was 31.5 cells/mm3 in the treated group versus 50 cells/mm3 in the placebo group, this difference being statistically not significant (p = 0.382). CONCLUSIONS: Patients with IVD have plasma zinc levels similar to those who achieve adequate immune recovery. Zinc supplementation in IVD patients showed a statistically non-significant difference in in CD4 levels between cases and controls. The results warrant a comparative study with a larger number of patients.

Changes in Age and Geographic Distribution of the Risk of Chagas Disease in Chile from 1989 to 2017.

The interruption of vector-borne transmission of Chagas disease was certified in Chile in 1999. Our goal was to determine the effects of the interruption of vector transmission on the age and spatial distributions of the risk of Chagas disease. We analyzed cases of Chagas disease by age and sex between 1989 and 2017, from notified disease reports of the Ministry of Health. Bayesian risk maps were constructed using the Besag-York-Mollie model. The reported cases of Chagas disease had a mean age of 45.9 ± 17.6 years. Small changes in the age distribution were found among different periods (χ215 = 602.4, p < 0.001). These were explained mainly by numbers lower than those expected in age groups 0-39 years in the 2011-2017 period. Part of the observed reduction in the proportion of individuals in the lower strata could be explained by the aging of the Chilean population. An increase of reported cases was detected after the interruption of vector-borne transmission (F1,327 = 4.24, p < 0.04), with regional differences (F14,1308 = 4.35, p < 0.001). The regions of the north-central area that have the highest burden of Chagas tended to decrease the relative risk, while the regions of the south tended to increase and small risk areas appear in zones where there are no insect vectors. There is still no clear evidence of a reduction in the reported cases in Chile. This could be explained mainly by an improvement in the detection of cases, but it cannot be ruled out that vector transmission still exists. The changes in distribution suggest potential impact from human internal migration and blood transfusion. This study provides strong evidence supporting the idea that entomological surveillance and long-term follow-up of Chagas disease need to be maintained after certification of interruption in endemic countries.

COVID-19 en Chile: la utilidad de los modelos epidémicos simples en la práctica / COVID-19 in Chile: the usefulness of simple epidemic models in practice

Objetivos El objetivo general ha sido describir y evaluar el valor predictivo de tres modelos durante el desarrollo de la epidemia COVID-19 en Chile, aportando conocimiento para la toma de decisiones en salud. Métodos Desarrollamos tres modelos a lo largo de la epidemia: un modelo discreto para predecir a corto tiempo la máxima carga sobre el sistema de salud, un modelo básico SEIR (susceptibles-expuestos-infectados-removidos) con ecuaciones discretas; un modelo SEIR estocástico con método de Montecarlo; y un modelo de tipo Gompertz para la Región Metropolitana (Santiago). Resultados El modelo de máxima carga potencial ha sido útil durante todo el seguimiento de la epidemia proporcionando una cota superior para el número de casos, la ocupación de unidades de cuidados intensivos y el número de fallecidos. Los modelos SEIR determinístico y estocástico tuvieron gran utilidad en la predicción del ascenso de los casos, el máximo y el inicio del descenso de casos, perdiendo utilidad en la situación actual por el reclutamiento asincrónico de casos en las regiones y la persistencia de una endemia alta. El modelo de Gompertz ha tenido un mejor ajuste en el descenso ya que esta captura mejor la asimetría de la curva epidémica en Santiago. Conclusiones Los modelos han demostrado gran utilidad en el seguimiento de la epidemia en Chile, con distintos objetivos en distintas etapas de la epidemia. Han complementado los indicadores empíricos como casos reportados, letalidad, fallecimientos y otros, permitiendo predecir situaciones de interés y visualizar la conducta a corto y largo plazo de esta pandemia a nivel local.

Objectives The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. Methods We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time frame­a basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. Results The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curve's asymmetry in Santiago. Conclusions The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

Estudio de un neo-epítope para detección de anticuerposantitransglutaminasa en enfermedad celíaca / Validation of a new antigen for detection of anti-transglutaminase antibodies in celiac disease

Introducción: La enfermedad celíaca (EC) es una patología autoinmune, que se desarrolla a cualquier edad en personas genéticamentesusceptibles, y cuyo órgano diana principal es el intestino delgado. La diversidad en las formas de presentación actualmente conocidas implica un desafío permanente para el laboratorio, que debe ofrecer nuevas técnicas, cada vez más sensibles y específicas, para detectar de manera eficiente los autoanticuerpos específicos para el diagnóstico y seguimiento de estos pacientes. Nuestro objetivo fue evaluar la sensibilidad y especificidad de un nuevo antígeno para la detección de anticuerpos anti-transglutaminasa compuesto por transglutaminasa tisular unida covalentemente a péptidos deamidados de gliadina (neo-epítope) en pacientes con sospecha de EC, con biopsia duodenal como gold standard. Como objetivo secundario nos propusimos evaluar la sensibilidad y especificidad del antígeno convencional, transglutaminasa humana recombinante, para el mismo grupo de estudio. Metodología: Se realizó un estudio prospectivo, analizando muestras de pacientes con sospecha de EC o en seguimiento de dicha patología, en las que se estudiaron los anticuerpos anti-transglutaminasa con antígeno neo- epítope, y con antígeno transglutaminasa recombinante humana. Se determinó sensibilidad, especificidad, VPP, VPN y coeficiente de concordancia Kappa. Resultados: Se procesaron 56 muestras, incluidas en un período de 5 meses. La sensibilidad (100%) y especificidad (92,3%) obtenidas con la técnica de neo-epítope, en relación a la biopsia (gold standard), fue mayor que con la técnica transglutaminasa humana recombinante (88,3% y 78,9% respectivamente). La técnica con neo-epítope proporcionó un menor número de resultados en la "zona de indeterminación". Conclusiones: Nuestros resultados concuerdan con otros autores, ya que neo-epítope detecta con mayor sensibilidad y especificidad aquellos pacientes con diferente situación de presentación y transgresores de la dieta libre de gluten, quienes pueden presentar serología negativa o débilmente positiva con transglutamiasa humana recombinante. La nueva técnica neo-epítope constituiría una mejor herramienta para la pesquisa diagnóstica y de seguimiento en pacientes con EC.

Introduction: Celiac disease (CD) is an autoimmune disease, which develops at any age in genetically susceptible people, and whose main target organ is the small intestine. The diversity in the currently known forms of presentation implies a permanent challenge for the laboratory, which must offer new techniques, increasingly sensitive and specific, to efficiently detect the specific autoantibodies that collaborate in the diagnosis and follow-up of these patients. Our main objective was to evaluate the sensitivity and specificity of a new sensitizing antigen for the detection of anti-transglutaminase antibodies composed of tissue transglutaminase covalently linked to deamidated gliadin peptides (neo-epitope) in patients with suspected CD, with duodenal biopsy as the gold standard. As a secondary objective, we set out to evaluate the sensitivity and specificity of the conventional antigen, recombinant human transglutaminase, for the same study group. Methodology: A prospective study was carried out, including samples from patients with suspected CD or in follow-up of said pathology, in which anti-transglutaminase antibodies were studied with neo-epitope antigen, and with human re-combinant transglutaminase antigen. Sensitivity, specificity, PPV, NPV and Kappa coefficient of concordance were determined. Results: 56 samples were processed, included in a period of 5 months. The sensitivity and specificity obtained with the neo-epitope technique (S: 100% - E: 92.3%), in relation to the biopsy (gold standard), was higher than with the recombinant human transglutaminase technique (S: 88.3% - E: 78.9%). The neo-epitope technique provided fewer results in the "zone of indeterminacy". Conclusions: Our results agree with other authors, since the neo-epitope detects with greater sensitivity and specificity those patients with different presentation situations and transgressors of the gluten-free diet, who can present negative or weakly positive serology with recombinant human transglutaminase. The new neo-epitope technique would constitute a better tool for diagnostic and follow-up research in patients with CD

Epidemic trends, public health response and health system capacity: the Chilean experience in four months of the COVID-19 pandemic.

OBJECTIVES: To report the surveillance of COVID-19 pandemic in Chile and analyse the response to public health interventions implemented from 3 March to 30 June 2020 and to assess the risks of collapse of the health care system. METHODS: We analysed the effective reproductive number, underreporting of cases, burden of critical beds, case fatality ratio and number of diagnostic RT-PCR for SARS-CoV-2. RESULTS: After an accelerated onset, the COVID-19 pandemic seemed to be relatively controlled in Chile (late April 2020), with reproductive numbers close to 1.00. However, at this time, the load of infected patients was high, with an important number of underreported cases; the diagnostic effort was still limited and heterogeneous across regions. After 1 May up to 30 June a marked exponential increase in the number of cases was observed with a peak on June 14. In this last period the occupation of intensive care unit beds increased to saturation level (89% nationally; 95% in the Metropolitan Region). CONCLUSIONS: Our findings suggest that the implemented public health interventions have been initially effective in decreasing the spread of the pandemic. Premature decisions to relax these interventions may have resulted in a rebound in cases with a rapid saturation of the health care system.

OBJETIVOS: Informar sobre la vigilancia de la pandemia por COVID-19 en Chile, analizar la respuesta a las intervenciones de salud pública implementadas desde el 3 de marzo hasta el 30 de junio de 2020 y evaluar los riesgos de colapso del sistema de salud. MÉTODOS: Se analizó el número reproductivo efectivo, el subregistro de casos, la carga sobre las camas de cuidados intensivos disponibles, la tasa de letalidad y el número de pruebas diagnósticas de RT-PCR efectuadas para el SARS-CoV-2. RESULTADOS: Tras un inicio acelerado, la pandemia por COVID-19 parecía estar relativamente controlada en Chile a finales de abril de 2020, con números reproductivos cercanos a 1,00. Sin embargo, en ese momento, la carga de pacientes infectados activos era elevada, con un número importante de casos no notificados; la capacidad diagnóstica era todavía limitada y heterogénea entre las regiones del país. Desde el 1 de mayo hasta el 30 de junio se observó un marcado incremento exponencial en el número de casos, con un pico el 14 de junio. En este último período la ocupación de camas en las unidades de cuidados intensivos aumentó hasta el nivel de saturación (89% a nivel nacional; 95% en la Región Metropolitana). CONCLUSIONES: Nuestros hallazgos sugieren que las intervenciones de salud pública implementadas parecen haber sido efectivas inicialmente para disminuir la propagación de la pandemia. Las decisiones prematuras de relajar estas intervenciones pueden haber ocasionado un rebote en los casos con una rápida saturación del sistema de atención de salud.

Epidemic trends, public health response and health system capacity: the Chilean experience in four months of the COVID-19 pandemic

[ABSTRACT]. Objectives. To report the surveillance of COVID-19 pandemic in Chile and analyse the response to public health interventions implemented from 3 March to 30 June 2020 and to assess the risks of collapse of the health care system. Methods. We analysed the effective reproductive number, underreporting of cases, burden of critical beds, case fatality ratio and number of diagnostic RT-PCR for SARS-CoV-2. Results. After an accelerated onset, the COVID-19 pandemic seemed to be relatively controlled in Chile (late April 2020), with reproductive numbers close to 1.00. However, at this time, the load of infected patients was high, with an important number of underreported cases; the diagnostic effort was still limited and heterogeneous across regions. After 1 May up to 30 June a marked exponential increase in the number of cases was observed with a peak on June 14. In this last period the occupation of intensive care unit beds increased to saturation level (89% nationally; 95% in the Metropolitan Region). Conclusions. Our findings suggest that the implemented public health interventions have been initially effective in decreasing the spread of the pandemic. Premature decisions to relax these interventions may have resulted in a rebound in cases with a rapid saturation of the health care system.

[RESUMEN]. Objetivos. Informar sobre la vigilancia de la pandemia por COVID-19 en Chile, analizar la respuesta a las intervenciones de salud pública implementadas desde el 3 de marzo hasta el 30 de junio de 2020 y evaluar los riesgos de colapso del sistema de salud. Métodos. Se analizó el número reproductivo efectivo, el subregistro de casos, la carga sobre las camas de cuidados intensivos disponibles, la tasa de letalidad y el número de pruebas diagnósticas de RT-PCR efectuadas para el SARS-CoV-2. Resultados. Tras un inicio acelerado, la pandemia por COVID-19 parecía estar relativamente controlada en Chile a finales de abril de 2020, con números reproductivos cercanos a 1,00. Sin embargo, en ese momento, la carga de pacientes infectados activos era elevada, con un número importante de casos no notificados; la capacidad diagnóstica era todavía limitada y heterogénea entre las regiones del país. Desde el 1 de mayo hasta el 30 de junio se observó un marcado incremento exponencial en el número de casos, con un pico el 14 de junio. En este último período la ocupación de camas en las unidades de cuidados intensivos aumentó hasta el nivel de saturación (89% a nivel nacional; 95% en la Región Metropolitana). Conclusiones. Nuestros hallazgos sugieren que las intervenciones de salud pública implementadas parecen haber sido efectivas inicialmente para disminuir la propagación de la pandemia. Las decisiones prematuras de relajar estas intervenciones pueden haber ocasionado un rebote en los casos con una rápida saturación del sistema de atención de salud.

Early laparoscopic cholecystectomy reduces hospital stay in mild gallstone pancreatitis. A randomized controlled trial.

BACKGROUND: Two strategies for same-admission cholecystectomy in mild gallstone pancreatitis (MGP) exist: early surgery (within 48-72 h from admission) and delayed surgery until resolution of symptoms and normalization of pancreatic tests. METHODS: This was a single-center, open-label RCT. Patients with MGP according to revised Atlanta classification-2012 and SIRS criteria were randomly assigned to early laparoscopic cholecystectomy (E-LC) within 72 h from admission or delayed laparoscopic cholecystectomy (D-LC). Laparoscopic-endoscopic rendezvous was performed when common bile duct stones were found at systematic intraoperative cholangiography. The primary outcome was length of stay (LOS), and the secondary outcomes were complications at 90 days, need for ERCP/choledocolithiasis, conversion, and re-admission. One year of follow-up was carried-on. RESULTS: At interim analysis, 52 patients were randomized (26 E-LC, 26 D-LC). E-LC versus D-LC was associated with a significantly shorter LOS (median 58 versus 167 h; P = 0.001). There were no differences in ERCP necessity for choledocolithiasis between the two approaches (E-LC 26.9% versus D-LC 23.1%, P = 1.00). No differences in postoperative complications were found. CONCLUSIONS: E-LC approach in patients with MGP significantly reduced LOS and was not associated with clinically relevant postoperative complications. TRIAL REGISTRATION: clinicaltrials.gov (NCT02590978).

Is neck circumference an appropriate tool to predict cardiovascular risk in clinical practice? A cross-sectional study in Chilean population.

OBJECTIVES: Neck circumference has emerged as a predictor of obesity and metabolic syndrome, but its clinical usefulness for different groups of population is not clearly defined. The aim is to evaluate the predictive capacity of neck circumference in order to detect cardiovascular risks (CVRs) on the Chilean population and to compare it with waist circumference performance. DESIGN: Cross-sectional study. SETTING: General Chilean population. PARTICIPANTS: Data of 4607 adults aged 18 and over from the Chilean National Health Survey 2009-2010 were analysed. PRIMARY AND SECONDARY OUTCOME MEASURES: Anthropometrics measures included neck and waist circumference, height and weight. CVR was identified according to the Framingham tables adapted for the Chilean population. Receiver operating characteristics curves and logistic regression models were made to evaluate the performance of neck circumference to predict a moderate/high CVR, comparing it to waist circumference. RESULTS: Almost 10% of the sample had a moderate or high CVR. The probability of having a moderate/high cardiovascular risk increase with cervical obesity (OR 1.95, 95% CI 1.04 to 3.68) and central obesity (OR 4.5, 95% CI 2.47 to 8.22). The area under the curves were high for cervical obesity (AUC 81.4%, 95% CI 78.8% to 84.0%) and central obesity (AUC 82.2%, 95% CI 79.7% to 84.7%) and not statistically different (p=0.152). CONCLUSIONS: Neck obesity has a high capacity to predict moderate/high CVR in the Chilean population. Its good performance appears as an opportunity to use it in clinical practice when waist circumference measurement is difficult to measure and eventually replace the waist circumference measurement as the technique is easier.