Background Coronavirus disease 2019 (COVID-19) has been associated to microvascular alterations. We screened the fundus of patients with COVID-19 to detect alterations of the retina and its vasculature and to assess possible correlations with clinical parameters. Methods Cross-sectional study. The presence of retinal alterations in patients with COVID-19 and subjects unexposed to the virus was assessed using fundus photographs and their prevalence was compared. Mean arteries diameter (MAD) and mean veins diameter (MVD) were compared between patients and unexposed subjects with multiple linear regression including age, sex, ethnicity, body mass index, smoking/alcohol consumption, hypertension, hyperlipidaemia, diabetes as covariates. The influence of clinical/lab parameters on retinal findings was tested in COVID-19 patients. Findings 54 patients and 133 unexposed subjects were enrolled. Retinal findings in COVID-19 included: haemorrhages (9·25%), cotton wools spots (7·4%), dilated veins (27·7%), tortuous vessels (12·9%). Both MAD and MVD were higher in COVID-19 patients compared to unexposed subjects (98·3 ± 15·3 µm vs 91·9 ± 11·7 µm, p = 0.006 and 138·5 ± 21·5 µm vs 123·2 ± 13·0 µm, p <0.0001, respectively). In multiple regression accounting for covariates MVD was positively associated with COVID-19 both in severe (coefficient 30·3, CI95% 18·1–42·4) and non-severe (coefficient 10·3, CI95% 1·6–19·0) cases compared to unexposed subjects. In COVID-19 patients MVD was negatively correlated with the time from symptoms onset (coefficient −1·0, CI 95% −1·89 to −0·20) and positively correlated with disease severity (coefficient 22·0, CI 95% 5·2–38·9). Interpretation COVID-19 can affect the retina. Retinal veins diameter seems directly correlated with the disease severity. Its assessment could have possible applications in the management of COVID-19. Funding None.

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Time-activity patterns and the airborne pollutant concentrations encountered by children each day are an important determinant of individual exposure to airborne particles. This is demonstrated in this work by using hand-held devices to measure the real-time individual exposure of more than 100 children aged 8-11 years to particle number concentrations and average particle diameter, as well as alveolar and tracheobronchial deposited surface area concentration. A GPS-logger and activity diaries were also used to give explanation to the measurement results. Children were divided in three sample groups: two groups comprised of urban schools (school time from 8:30 am to 1:30 pm) with lunch and dinner at home, and the third group of a rural school with only dinner at home. The mean individual exposure to particle number concentration was found to differ between the three groups, ranging from 6.2 × 10(4)part.cm(-3) for children attending one urban school to 1.6 × 10(4)part.cm(-3) for the rural school. The corresponding daily alveolar deposited surface area dose varied from about 1.7 × 10(3)mm(2) for urban schools to 6.0 × 10(2)mm(2) for the rural school. For all of the children monitored, the lowest particle number concentrations are found during sleeping time and the highest were found during eating time. With regard to alveolar deposited surface area dose, a child's home was the major contributor (about 70%), with school contributing about 17% for urban schools and 27% for the rural school. An important contribution arises from the cooking/eating time spent at home, which accounted for approximately 20% of overall exposure, corresponding to more than 200 mm(2). These activities represent the highest dose received per time unit, with very high values also encountered by children with a fireplace at home, as well as those that spend considerable time stuck in traffic jams.

Background Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P < 0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

The aim of this work was to quantify the exposure of children to particle resuspension in school gyms. In fact, although moderate standard aerobic activity is suggested for good health, adverse health effects could affect people exercising in micro-environments with ambient pollution. Overall, 12 micro-environments were chosen and analyzed in a 3-month experimental campaign. The different fractions of particulate matter (PM) were measured by means of photometers, calibrated for the specific aerosols studied through gravimetric samplers, whereas particle number distributions in the 0.5-20 μm range were continuously measured using an Aerodynamic Particle Sizer (APS) spectrometer. High PM concentration levels were measured in school gyms compared to outdoor values. The dominant source is the particle resuspension produced by the activity of exercising pupils and, among the various PM fractions, the effect on coarse particles (PM 10-2.5 ) was found to be the most important, with the related emissions factors measured in the range of 1.5-8.9 mg/min. During school activities, under natural ventilation conditions, the average coarse particle concentrations at the 12 school gyms investigated were found to be 4.8 ± 2.0 times higher than the background (outdoor) values. The key parameters are the number and intensity of the physical activities, which can be characterized by the total energy used by the students. Therefore, this study provides useful data on the exposure of students to airborne particles during periods of physical activity in gyms with natural ventilation.