Streptococcus pneumoniae serotype 19A in hospitalized children with invasive pneumococcal disease after the introduction of conjugated vaccines in Lima, Peru.

BACKGROUND: The Pneumococcal conjugate vaccine (PCV) has decreased cases of invasive pneumococcal disease (IPD) worldwide. However, the impact of PCVs introduction may be affected by the serotype distribution in a specific context. METHODS: Cross-sectional multicenter passive surveillance study of IPD cases in pediatric patients hospitalized in Lima, Peru between 2016 and 2019 (after PCV13 introduction) to determine the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae. Serotyping was performed by a sequential multiplex PCR and confirmed by whole genome sequencing. RESULTS: Eighty-five S. pneumoniae isolates were recovered (4.07/100,000 among children <60 months of age). Serotype 19A was the most common (49.4%). Children infected with serotype 19A in comparison with children infected with other serotypes were younger, had a lower rate of meningitis and higher rates of pneumonia, complicated pneumonia and antimicrobial resistance; 28.6% of patients with serotype 19A have received at least one dose of PCV13 vs. 62.8% of patients with other serotypes. Using MIC-breakpoints, 81.2% (56/69) of non-meningitis strains and 31.2% (5/16) of meningitis strains were susceptible to penicillin; 18.8% (3/16) of meningitis strains had intermediate resistance to ceftriaxone. Resistance to azithromycin was 78.8% (67/85). Serotype 19A frequency increased over time in the same study population, from 4.2% (4/96) in 2006-2008, to 8.6% (5/58) in 2009-2011, to 49.4% (42/85) in the current study (2016-2019) (p < 0.001). CONCLUSIONS: After PCV13 introduction in Peru, serotype 19A remains the most prevalent; however, the vaccination coverage is still not optimal. Therefore, additonal surveillance studies are needed to determine the remaining IPD burden.

Pneumococcal serotypes and antibiotic resistance in healthy carriage children after introduction of PCV13 in Lima, Peru.

OBJECTIVE: To determinate the frequency of Streptococcus pneumoniae nasopharyngeal carriers, serotypes and antimicrobial resistance in healthy children in Lima, Peru, post-PCV13 introduction and to compare the results with a similar study conducted between 2006 and 2008 before PCV7 introduction (pre-PCV7). METHODS: A cross-sectional multicenter study was conducted between January 2018 and August 2019 in 1000 healthy children under two years of age. We use standard microbiological methods to determinate S. pneumoniae from nasopharyngeal swab, Kirby Bauer and minimum inhibitory concentration methods to determinate antimicrobial susceptibility and whole genomic sequencing to determinate pneumococcal serotypes. RESULTS: The pneumococcal carriage rate was 20.8 % vs. 31.1 % in pre-PCV7 (p < 0.001). The most frequent serotypes were 15C, 19A and 6C (12.4 %, 10.9 % and 10.9 % respectively). The carriage of PCV13 serotypes after PCV13 introduction decreased from 59.1 % (before PCV7 introduction) to 18.7 % (p < 0.001). Penicillin resistance was 75.5 %, TMP/SMX 75.5 % and azithromycin 50.0 %, using disk diffusion. Penicillin resistance rates using MIC breakpoint for meningitis (MIC ≥ 0.12) increased from 60.4 % to 74.5 % (p = 0.001). CONCLUSION: The introduction of PCV13 in the immunization program in Peru has decreased the pneumococcal nasopharyngeal carriage and the frequency of PCV13 serotypes; however, there has been an increase in non-PCV13 serotypes and antimicrobial resistance.

Peak apical recoil rate is a simplified index of left ventricular untwist: validation and application for assessment of diastolic function in children.

The use of untwisting rate as a novel index of LV diastolic function in clinical practice has been limited due to its tedious and time-consuming analysis. Therefore, we simplify the untwist measurement by only measuring the LV apex's recoil rate and validating and applying peak apical recoil rate (PARR) as an index of diastolic dysfunction (DD) in pediatric subjects during increased and decreased lusitropic states. We recruited 153 healthy subjects (mean age 13.8 ± 2.9 years), of whom 48 performed straight leg raising exercise and an additional 46 patients (mean 8.4 ± 5.6 years) with documented pulmonary capillary wedge pressures (PCWP) (validation cohort). In addition, we studied 16 dilated cardiomyopathy patients (mean age 9.5 ± 6.3 years) (application cohort). PARR and isovolumic relaxation time (IVRT) were compared to PCWP. Both PARR and PARR normalized by heart rate (nPARR) were excellent in detecting patients with PCWP ≥ 12 mmHg and greatly superior to IVRT in this respect (AUC: 0.98, 95% CI [0.96, 1.0] vs. AUC: 0.7 95%CI [0.54,0.86]). In DCM patients, PARR and nPARR were greatly decreased compared to controls (- 38.6 ± 18.6º/s vs - 63.1 ± 16.3º /s, p < 0.001) and (- 0.43 ± 0.20 º/ s/min vs - 0.83 ± 0.28º/s/min, p < 0.0001) but increased with straight leg raising exercise (- 59.4 ± 19.4º/s vs - 97.8 ± 39.0 º/s, p < 0.01) and - 0.85 ± 0.36 vs - 1.4 ± 0.62 º/s/min (p < 0.0001) respectively. PARR and nPARR successfully detected increased and decreased lusitropic states and superior to IVRT in correlation with PCWP. This highly reproducible parameter offers incremental value over traditional indices of DD and may potentially serve as a useful index of elevated PCWP in children.

Analysis of posts and comments about ivermectin on Facebook during the COVID-19 pandemic in Peru / Análisis de publicaciones y comentarios sobre la ivermectina en Facebook durante la pandemia del COVID-19 en Perú

This research was carried out with the objective of analyzing the posts and perceptions of users, through their comments, about the drug ivermectin on Facebook during the COVID-19 pandemic in Peru. The pots and their comments were selected by manual search using the terms: "ivermectina" and "#ivermectina" in July 2020. The analysis of posts and their comments was made by conventional content analysis with an inductive process and supported by scientific bibliography. There were 17 posts made between May 18 and July 7, 2020, and were classified into 5 topics: rumors (58.8%), based on scientific evidence (11.8%), precaution (11.8%), production of the drug (11.8%) and confrontation (5.9%). Surprisingly, 70.0% of the rumors were offered by media pages. Regarding the comments, these were classified identifying the perceptions of users towards ivermectin into four topics: ivermectin as an "effective cure" (64.8%), request for information on ivermectin (25.3%), against the consumption of ivermectin (6.3%) and other treatments (3.6%). In conclusion, it was identified that more than half of the information about ivermectin that circulates through Facebook posts was classified as "rumors", and most of them were originates from media pages; regarding the analysis of the comments, the perception of users who consider ivermectin as the "effective cure" against COVID-19 stands out over other perceptions.

Esta investigación se realizó con el objetivo de analizar las publicaciones y percepciones de los usuarios, a través de sus comentarios, sobre el fármaco ivermectina en Facebook durante la pandemia del COVID-19 en Perú. Las publicaciones y sus comentarios fueron seleccionados mediante búsqueda manual utilizando los términos: "ivermectina" y "#ivermectina" en julio del 2020. La interpretación de las publicaciones y sus comentarios se efectuó por análisis de contenido cualitativo convencional con proceso inductivo y apoyado por literatura científica. Se encontraron 17 publicaciones realizadas entre el 18 de mayo y 7 de julio del 2020, clasificándose en 5 temáticas: rumores (58,8%), basada en evidencia científica (11,8%), precaución (11,8%), producción del fármaco (11,8%) y confrontación (5,9%). Paradójicamente, el 70,0% de los rumores fueron ofrecidos por páginas de medios de comunicación. En cuanto a los comentarios, estos se clasificaron identificando las percepciones de los usuarios hacia la ivermectina en cuatro temas: ivermectina como "cura efectiva" (64,8%), solicitud de información sobre ivermectina (25,3%), en contra del consumo de ivermectina (6,3%) y otros tratamientos (3,6%). En conclusión, se identificó que más de la mitad de la información sobre ivermectina que circula mediante publicaciones en Facebook se clasifican como "rumores", y en su mayoría son originadas por páginas de medios de comunicación; en cuanto al análisis de los comentarios se destaca la percepción de los usuarios que consideran a la ivermectina como la "cura efectiva" contra la COVID-19.

Decreased right ventricular longitudinal strain in children with hypoplastic left heart syndrome during staged repair and follow-up: does it have implications in clinically stable patients?

The principal aim of this study was to evaluate changes in systolic function in the single right ventricle (SRV), during progression of the same patient through the three stages of surgical repair for hypoplastic left heart syndrome and during a 5-year follow-up. We hypothesize that, SRV global longitudinal strain (GLS) will be low during 3 stages of repair even in stable patients. We retrospectively evaluated 140 echocardiograms in 20 patients with HLHS (ages 0-11.3 years), before and after 3 stages of surgical palliation. Five-year follow-up data were available in all 20 patients. Controls with structurally normal hearts and in the same age group were used for comparison. We utilized speckle-tracking imaging for assessment of SRV segmental and global longitudinal and circumferential strains, from previously acquired 4-chamber and mid-cavity short-axis views prior to and within 1-3 months of each surgical stage. Longitudinal strain (LS) remained low through all 3 stages of repair and during follow-up. The pre-Fontan stage demonstrated significant interstage improvement compared to the post-Glenn stage despite similar volume status. Global LS was (- 15.6 ± 4.5% after Fontan surgery and remained similar (- 15.32 ± 3.2%) 5 years later. The SRV also showed increased dominance of circumferential strain compared to the normal RV, where the longitudinal deformation was dominant. In SRV, longitudinal strain may be a useful clinical index for evaluating both segmental and global function in an objective manner. Due to lack of significant clinical deterioration over a 10-year period, we speculate that a "lower-than-normal" longitudinal strain may be used as an objective measure of SRV function in clinically stable patients, particularly after the Fontan operation. Compensatory mechanisms where the longitudinal pattern of contraction switches to a more circumferential pattern, may play a role in asymptomatic patients with HLHS.

Left atrial mechanics in children: insights from new applications of strain imaging.

Our principal aim was to describe functional changes in dilated left atrium (LA) of children by using new applications of LA strain. We studied 66 patients (age range 0.2-22 years) consisting of 33 with LA enlargement. We utilized speckle-tracking imaging for assessment LA longitudinal strain (S) and longitudinal displacement (D). S-D loops were generated by plotting S and D data along Y and X axes, respectively. We also measured noninvasive LA stiffness index, [Formula: see text] (%-1). Peak S in controls was 51.16 ± 19.45% versus 23.16 ± 13.66% in dilated LA (p < 0.0001). S-D loops in dilated LA group were significantly smaller compared to controls (2.62 ± 2.88 units vs. 5.24 ± 4.00 units, p < 0.01). Noninvasive LA stiffness index was higher in dilated LA group (0.77 ± 0.63%-1 vs. 0.17 ± 0.07%-1, p < 0.0001). A cut-off LA stiffness value of 0.25%-1 was found to maximize sensitivity and specificity (84.0% and 84.85%, respectively). Children with enlarged LA demonstrate decreased peak S, abnormal S-D loops and increased LA stiffness, providing a newer insight into LA function. Evaluation of LA mechanics may be applied in future as a surrogate for left ventricular filling parameters.

A Preliminary Study of Left Ventricular Rotational Mechanics in Children with Noncompaction Cardiomyopathy: Do They Influence Ventricular Function?

BACKGROUND: Current diagnostic criteria for noncompaction cardiomyopathy (NCC) lack specificity, and the disease lacks prognostic indicators. Reverse apical rotation (RAR) with abnormal rotation of the cardiac apex in the same clockwise direction as the base has been described in adults with NCC. The aim of this study was to test the hypothesis that RAR might differentiate between symptomatic NCC and benign hypertrabeculations and might be associated with ventricular dysfunction. METHODS: Echocardiograms from 28 children with NCC without cardiac malformations were prospectively compared with those from 29 age-matched normal control subjects. A chart review was performed to identify the patients' histories and clinical characteristics. Speckle-tracking was used to measure longitudinal strain, circumferential strain, and rotation. RESULTS: RAR occurred in 39% of patients with NCC. History of left ventricular (LV) dysfunction or arrhythmia was universal in, but not exclusive to, patients with RAR. Patients with RAR had lower LV longitudinal strain but similar ejection fractions compared with patients without RAR (median, -15.6% [interquartile range, -12.9% to -19.3%] vs -19% [interquartile range, -14.5% to -21.9%], P < .01; 53% [interquartile range, 43% to 68%] vs 61% [interquartile range, 58% to 67%], P = .08). Only a pattern of contraction with RAR, early arrest of twisting by mid-systole, and premature untwisting was associated with lower ejection fraction (46%; interquartile range, 43% to 52%; P = .006). CONCLUSIONS: RAR is not a sensitive but is a specific indicator of complications in children with NCC. Therefore, RAR may have prognostic rather than diagnostic value. Premature untwisting of the left ventricle during ejection may be an even more worrisome indicator of LV dysfunction.

Right atrial mechanics provide useful insight in pediatric pulmonary hypertension.

Right atrial (RA) mechanics have been studied infrequently in children in the past due to technical constraints. With the advent of strain imaging, RA physiology can now be studied in greater detail. The principal aim of this study was to describe functional changes in right heart mechanics of children with idiopathic pulmonary arterial hypertension (PAH), by using new applications of RA strain. In this retrospective study, we evaluated RA mechanics of 20 patients (age range = 3-23 years) with PAH and 18 control patients. RA longitudinal strain (RALS) and longitudinal displacement (LD) were calculated by speckle-tracking echocardiography. RALS was plotted against LD, producing a characteristic strain-displacement (S-D) loop. Standard indices of right heart function and right heart catheterization data were obtained. Patients were clinically subdivided into "compensated" and "decompensated" PAH. A chart review was performed to identify patients who subsequently developed adverse outcomes, including death, awaiting or received lung and/or heart transplantation. RALS was significantly lower in decompensated PAH compared with both controls and compensated PAH. Area enclosed by S-D loops differed significantly between the compensated and decompensated PAH subgroups (5.33 [3.90-9.44] versus 1.83 [1.17-2.36], P < 0.05). S-D loop area and RALS possessed high sensitivity and specificity compared to other parameters for identifying children with PAH who subsequently developed adverse outcomes. In particular, their sensitivities and specificities were greatly superior compared to those of tricuspid annular plane systolic excursion (TAPSE). RALS may represent a useful metric for assessing right ventricular (RV) dysfunction. S-D loops, composed over an entire cardiac cycle, may present useful, composite information regarding both systolic and diastolic right heart function. RA mechanics may serve as useful tools for identifying patients with more severe PAH, who are at risk for future adverse outcomes associated with RV failure.

Left Ventricular Rotational Mechanics in Children After Heart Transplantation.

BACKGROUND: Left ventricular (LV) dysfunction after orthotopic heart transplantation (OHT) is multifactorial and can be an indicator of graft rejection or coronary artery vasculopathy. Analysis of rotational mechanics may help in the early diagnosis of ventricular dysfunction. Studies describing the left ventricular rotational strain in children after OHT are lacking. It is important to establish the baseline rotational mechanics in pediatric OHT to pursue further studies in this population. METHODS AND RESULTS: Rotational strain measured by speckle tracking was compared in 32 children after OHT, with no evidence of active rejection or coronary artery vasculopathy with 35 age-matched normal controls. Twelve OHT patients and 13 controls underwent moderate exercise with pre- and postexercise echocardiography. Torsion, slope of the systolic limb of the torsion-radial displacement loop, and the untwist rate were significantly higher in OHT patients (torsion: median 2.7°/cm [Q1-Q3, 2.3-3.2] versus 2.3°/cm [Q1-Q3, 1.9-2.7]; P=0.03, torsion-radial displacement loop: 2.7°/mm [Q1-Q3, 2.1-3.6] versus 2.0°/mm [Q1-Q3, 1.6-2.7]; P=0.008, indexed peak untwist rate: -21.6°/s/cm [Q1-Q3, -24.3 to -15.7] versus -17.1°/s/cm [Q1-Q3, -19.6 to -13.3]; P=0.01). Contrary to controls, OHT recipients were unable to increase torsion with exercise (OHT: 2.8°/cm [2.7-3.2] versus 3°/cm [2.4-3.5]; P=0.81, controls: 2.2°/cm [2-2.6] versus 3°/cm [2.4-3.7]; P=0.01, pre and post exercise, respectively). The systolic slope of the torsion-radial displacement loop relationship decreased with exercise in most OHT patients. CONCLUSIONS: Baseline rotational strain in OHT patients is higher than normal with a blunted response to exercise. The slope of torsion-radial displacement loop, and its response to exercise, may serve as a marker of left ventricular dysfunction in OHT patients.