OBJECTIVE: A multicentric, cross-sectional study was carried out to determine the prevalence and risk factors for Coronavirus disease 2019 in medical students and residents from four universities and affiliated hospitals in Brazil. METHODS: A survey about contamination risk and symptoms was sent to all participants through email and WhatsApp. Prevalence was measured by the self-report of positive polymerase chain reaction or serological test. Univariate and multivariate analyses were performed, and odds ratio and 95% confidence interval were calculated. RESULTS: Prevalence of infection by Sars-CoV-2 was 14.9% (151/1011). The disease was more prevalent in residents and interns than in undergraduate students. Contact with an infected relative outside the hospital or with colleagues without using personal protective equipment was associated with higher contamination. Contact with patients without wearing goggles and higher weekly frequency of contact were the two factors independently associated with the infection by Coronavirus disease 2019 in the multivariate analysis. CONCLUSIONS: Medical students, interns, and residents have a higher prevalence of Coronavirus disease 2019 than the general population, in which the last two groups are significantly at higher risk. Contacting patients at a higher weekly frequency increases the risk for infection. The use of goggles should be reinforced when contacting patients.

Purpose: Myopia has been considered a public health issue by the World Health Organization since 2015.The growing incidence of myopia worldwide, called the myopia epidemic, and its potential blinding complications in adulthood like cataract, glaucoma, retinal detachment and maculopathy, have been extensively published and discussed in peer review papers. Nonetheless, little information about Latin America is available. This study aims to detect the prevalence of myopia in southern Brazil, the biggest country of South America. Methods: A prospective cross sectional study recruited 330 public school children between 2019 and 2021, aged 5 to 20 years old. All children underwent a comprehensive eye examination and detailed lifestyle questionnaire. The Pearson correlation coefficient, Kruskal Wallys and the Chi-Square Test were used to assess simple correlations and associations between myopia and medical conditions, use of medications, ophthalmic history and family history of ocular conditions, besides demographics and lifestyle focused on screen time/day. Associations between the results of the ophthalmologic evaluation and all factors included in the questionnaire were analyzed using the Generalized Estimating Equation model (GEE). The prevalence of hyperopia and astigmatism were also assessed. Results: Total prevalence of myopia was 17.4% (CI 13.8 – 21.7%). Low myopia (-0.50D to -5.75D) comprised 15.2% (CI 11.9 – 19.3%) and high myopia (-6,00D or worse) was 2.1% (CI 1.1 – 4.1%). Relative risk of myopia for females was 1.6 (CI 1.00 – 2.57%) and each additional hour of screen time increased a child’s chance of having myopia by 6.5%. The prevalence of hyperopia was 7,7% (CI 5.4 -10.9%) and of astigmatism, either myopic or hyperopic, was 25.6% (CI 21.4 – 30.2%). Conclusions: Brazil has always been considered a hyperopic country. These are the highest reported prevalences of myopia under cycloplegia and the first paper to present myopia as a more prevalent refractive error than hyperopia among Brazilian school children to date.