Detection of SARS-CoV-2 infection in a pediatric population from south Italy without symptoms of Coronavirus Disease 2019.

BACKGROUND: SARS-CoV-2 has had dramatic consequences on the world population in morbidity and mortality and socially. Clinical manifestations range from common cold-like to more severe disease such as bronchitis, pneumonia, severe acute respiratory distress syndrome, multi-organ failure and even death. The pediatric population may be infected with SARS-CoV-2, but is less likely to be symptomatic or develop severe symptoms. METHODS: We analyzed a cohort of pediatric subjects from Campania Region, south Italy, without symptoms of SARS-CoV2, to evaluate the distribution of infection in relation to gender and age. Detection on nasopharyngeal swabs was performed with two different RT-PCR methods, a qualitative rapid test (VitaPCRTM SARS-CoV-2 assay) and a quantitative test (SARS-CoV-2 ELITe MGB® assay). RESULTS: Positive subjects were 52.63% male and 47.36% female. Regarding age distribution, we described a consistent increase of detection rate (82.45%) in 0-2 year-old patients. CONCLUSION: The importance of children in transmitting the virus remains uncertain; however our analysis of the distribution of the infection in these subjects may help monitor SARS-CoV2 spread in the general population.

Characterization of respiratory infection viruses in hospitalized children from Naples province in Southern Italy.

Most acute respiratory infections (ARIs) in children are due to viral etiology, and represent an important cause of mortality and morbidity in children <5 years old in developing countries. The pathogens that cause ARIs vary geographically and by season, and viruses serve a major role. In the present study, the distribution of the seven respiratory viruses that are more prevalent in Southern European countries were retrospectively analyzed in a Southern Italy Hospital, that centralizes pediatric diseases from the Naples province. Viruses were categorized by a FilmArray Respiratory Panel, and demonstrated no substantial differences in sex, age and seasonal viruses distribution. However, all the investigated viruses had a higher detection rate in the surrounding municipalities than in the metropolitan area of Naples. In recent years, the association between air pollution and respiratory infections has become an increasing public health concern. The data in this study support this association in the surrounding areas of Naples extensively contaminated by environmental toxic agents. In these areas, characterization of the epidemiology of ARIs is required to implement a prevention and control program.

Changes in the concentration of breath ammonia in response to exercise: a preliminary investigation.

Breath ammonia has proven to be a difficult compound to measure accurately. The goal of this study was to evaluate the effects that the physiological intervention, exercise, had on the levels of breath ammonia. The effects of vigorous exercise (4000 m indoor row) in 13 participants were studied and increases in breath ammonia were observed in all participants. Mean pre-exercise concentrations of ammonia were 670 pmol ml(-1) CO2 (SD, 446) and these concentrations increased to post-exercise maxima of 1499 pmol ml(-1) CO2 (SD, 730), p < 0.0001. The mean increase in ammonia concentrations from pre-exercise to maximum achieved in conditioned (1362 pmol ml(-1) CO2) versus non-conditioned rowers (591 pmol ml(-1) CO2) were found to be statistically different, p = 0.029. Taken together, these results demonstrate our ability to repeatedly measure the influence of exercise on the concentration of breath ammonia.

Factors influencing breath ammonia determination.

Amongst volatile compounds (VCs) present in exhaled breath, ammonia has held great promise and yet it has confounded researchers due to its inherent reactivity. Herein we have evaluated various factors in both breath instrumentation and the breath collection process in an effort to reduce variability. We found that the temperature of breath sampler and breath sensor, mouth rinse pH, and mode of breathing to be important factors. The influence of the rinses is heavily dependent upon the pH of the rinse. The basic rinse (pH 8.0) caused a mean increase of the ammonia concentration by 410 ± 221 ppb. The neutral rinse (pH 7.0), slightly acidic rinse (pH 5.8), and acidic rinse (pH 2.5) caused a mean decrease of the ammonia concentration by 498 ± 355 ppb, 527 ± 198 ppb, and 596 ± 385 ppb, respectively. Mode of breathing (mouth-open versus mouth-closed) demonstrated itself to have a large impact on the rate of recovery of breath ammonia after a water rinse. Within 30 min, breath ammonia returned to 98 ± 16% that of the baseline with mouth open breathing, while mouth closed breathing allowed breath ammonia to return to 53 ± 14% of baseline. These results contribute to a growing body of literature that will improve reproducibly in ammonia and other VCs.

Forced expiratory capnography and chronic obstructive pulmonary disease (COPD).

This report proposes a potentially sensitive and simple physiological method to detect early changes and to follow disease progression in obstructive pulmonary disease (COPD) based upon the usual pulmonary function test. Pulmonary function testing is a simple, although relatively insensitive, method to detect and follow COPD. As a proof-of-concept, we have examined the slope of the plateau for carbon dioxide during forced expiratory capnography in healthy (n = 10) and COPD subjects (n = 10). We compared the change in the rate of exhalation of carbon dioxide over time as a marker of heterogeneous ventilation of the lung. All subjects underwent pulmonary function testing, body-plethysmography, and forced exhalation capnography. The subjects with COPD also underwent high-resolution computed tomography of the chest. Regression lines were fitted to the slopes of the forced exhalation capnogram curves. There was no difference in the mean levels of exhaled carbon dioxide between the COPD and the healthy groups (p > 0.48). We found a significant difference in the mean slope of the forced exhalation capnogram for the COPD subjects compared to the healthy subjects (p = 0.01). Most important, for the COPD subjects, there was a significant positive correlation between the slope of the forced exhaled capnogram and a defined radiodensity measurement of the lung by high-resolution computed tomography (r(2) = 0.49, p = 0.02). The slope of the forced exhalation capnogram may be a simple way to determine physiological changes in the lungs in patients with COPD that are not obtainable with standard pulmonary function tests. Forced exhalation capnography would be of great clinical benefit if it can identify early disease changes and at-risk individuals.

Methodologies for anti-HLA antibody screening in patients awaiting kidney transplant: a comparative study.

OBJECTIVES: The relevance of anti-HLA antibodies in patients awaiting kidney transplants is well recognized. During the past 40 years, kidney transplant candidates have been tested for these antibodies, and the choice of the detection assay has become essential. Recently, the pioneer method, the complement-dependent cytotoxicity, has been integrated but has not been replaced by more-sensitive solid-phase assays, such as the enzyme-linked immunosorbent assay and the bead-based technology (ie, flow cytometry: FlowPRA, and FlowAnalyzer: Luminex). MATERIALS AND METHODS: We compared the sensitivity and antibody specificity of these 4 techniques for detecting panel-reactive antibodies in a population of 101 consecutive patients awaiting a renal transplant (which had already resulted positive in a prescreening analysis). RESULTS: Sera positive for class I and class II antibodies were 62 and 90 as assessed by the complement-dependent cytotoxicity method, 76 and 58 by using enzyme-linked immunosorbent assay, 83 and 65 with Flow-panel-reactive antibodies, and 90 and 79 by Luminex. Luminex gave more positive scores than the others for class I HLA antibodies, whereas complement-dependent cytotoxicity revealed more positives for those of class II. CONCLUSIONS: Although Luminex appears more efficient among these assays, our results indicate that use of multiple methods is still the best approach for characterizing the immunologic status of these patients.