Clinical Profile of Refractive Errors Associated with Screen Time in Children Aged 5-15 Years in a Tertiary Care Hospital of Southern India during COVID Pandemic: A Prospective Study

Introduction: Refractive errors cannot be prevented, but it is important to detect them early to improve the quality of life and prevention of blindness. Refractive errors screening in children during COVID pandemic was difficult task as they were high-risk group. Increased near activity due to online classes and smart devices usage may increase the uncorrected refractive errors. The study emphasizes on the refractive errors screening during COVID pandemic. Aim(s): To study the clinical profile of refractive errors of the children aged 5-15 years in a tertiary care hospital in COVID pandemic in association with screen time, outdoor activity, type of gadget, amblyopia and educational status of mother. Material(s) and Method(s):This was a hospital based prospective analytical study conducted in children 5-15 yrs attending the Ophthalmology Outpatient Department of ESIC Medical College and Hospital from May 2021 to October 2021.Children were screened for refractive errors and compared with the refractive errors data of different children of same age referred from Paediatric Outpatient Department and who attended to Ophthalmology Outpatient Department for regular eye checkup in pre-pandemic time. Unaided visual acuity of all children were measured with the help of Snellen's chart. Children with refractive errors underwent Cycloplegic Retinoscopy followed by post-mydriatic test. Screen time and outdoor activity duration were recorded. Interpretation and analysis of obtained results was carried out using Statistical Package for Social Sciences version 22.0 for descriptive statistics. Non-parametric tests like Pearson Chi-square test were used to express the qualitative data.Data with p-value less than 0.05 was considered statistically significant. Result(s): A total of 790 children were screened out of which 358 (45.3%) presented with refractive error when compared with the pre pandemic prevalence 276 (34.9%) out of 790 children screened, presented with the refractive error. A total of 118 (33%) of the children presented with increased blink rate associated with increased screen time and dry eye. Rate of progression of more than 1D was observed in 44 (12.29%) of which Myopia 28 (7.8%) Astigmatism 10 (2.7%) and hypermetropia 6 (1.6%) in 6 months. A total of 286 (79.8%) children presented with myopia and 24 (6.7%) presented with hypermetropia, 48 (13.4%) presented with astigmatism. A total of 258 (72.06%) presented with screen time for 4-7 hrs, and 32 (8.9%) children presented with amblyopia. Conclusion(s): Refractive errors increased due to smart classes in schools or use of laptops, television viewing, computers or mobiles. Hence, this reinforces the need to screen all the school going children and children with the history of gadgets use. Copyright © 2022 Journal of Clinical and Diagnostic Research. All rights reserved.

Quantifying the impact of immune history and variant on SARS-CoV-2 viral kinetics and infection rebound: A retrospective cohort study.

Background: The combined impact of immunity and SARS-CoV-2 variants on viral kinetics during infections has been unclear. Methods: We characterized 1,280 infections from the National Basketball Association occupational health cohort identified between June 2020 and January 2022 using serial RT-qPCR testing. Logistic regression and semi-mechanistic viral RNA kinetics models were used to quantify the effect of age, variant, symptom status, infection history, vaccination status and antibody titer to the founder SARS-CoV-2 strain on the duration of potential infectiousness and overall viral kinetics. The frequency of viral rebounds was quantified under multiple cycle threshold (Ct) value-based definitions. Results: Among individuals detected partway through their infection, 51.0% (95% credible interval [CrI]: 48.3-53.6%) remained potentially infectious (Ct <30) 5 days post detection, with small differences across variants and vaccination status. Only seven viral rebounds (0.7%; N=999) were observed, with rebound defined as 3+days with Ct <30 following an initial clearance of 3+days with Ct ≥30. High antibody titers against the founder SARS-CoV-2 strain predicted lower peak viral loads and shorter durations of infection. Among Omicron BA.1 infections, boosted individuals had lower pre-booster antibody titers and longer clearance times than non-boosted individuals. Conclusions: SARS-CoV-2 viral kinetics are partly determined by immunity and variant but dominated by individual-level variation. Since booster vaccination protects against infection, longer clearance times for BA.1-infected, boosted individuals may reflect a less effective immune response, more common in older individuals, that increases infection risk and reduces viral RNA clearance rate. The shifting landscape of viral kinetics underscores the need for continued monitoring to optimize isolation policies and to contextualize the health impacts of therapeutics and vaccines. Funding: Supported in part by CDC contract #200-2016-91779, a sponsored research agreement to Yale University from the National Basketball Association contract #21-003529, and the National Basketball Players Association.

Severe Acute Respiratory Syndrome Coronavirus 2 Reinfection: A Case Series From a 12-Month Longitudinal Occupational Cohort.

Findings are described in 7 patients with severe acute respiratory syndrome coronavirus 2 reinfection from the National Basketball Association 2020-2021 occupational testing cohort, including clinical details, antibody test results, genomic sequencing, and longitudinal reverse-transcription polymerase chain reaction results. Reinfections were infrequent and varied in clinical presentation, viral dynamics, and immune response.

Viral dynamics and duration of PCR positivity of the SARS-CoV-2 Omicron variant (preprint)

Background. The Omicron SARS-CoV-2 variant is responsible for a major wave of COVID-19, with record case counts reflecting high transmissibility and escape from prior immunity. Defining the time course of Omicron viral proliferation and clearance is crucial to inform isolation protocols aiming to minimize disease spread. Methods. We obtained longitudinal, quantitative RT-qPCR test results using combined anterior nares and oropharyngeal samples (n = 10,324) collected between July 5th, 2021 and January 10th, 2022 from the National Basketball Association's (NBA) occupational health program. We quantified the fraction of tests with PCR cycle threshold (Ct) values <30, chosen as a proxy for potential infectivity and antigen test positivity, on each day after first detection of suspected and confirmed Omicron infections, stratified by individuals detected under frequent testing protocols and those detected due to symptom onset or concern for contact with an infected individual. We quantified the duration of viral proliferation, clearance rate, and peak viral concentration for individuals with acute Omicron and Delta variant SARS-CoV-2 infections. Results. A total of 97 infections were confirmed or suspected to be from the Omicron variant and 107 from the Delta variant. Of 27 Omicron-infected individuals testing positive [≤]1 day after a previous negative or inconclusive test, 52.0% (13/25) were PCR positive with Ct values <30 at day 5, 25.0% (6/24) at day 6, and 13.0% (3/23) on day 7 post detection. Of 70 Omicron-infected individuals detected [≥]2 days after a previous negative or inconclusive test, 39.1% (25/64) were PCR positive with Ct values <30 at day 5, 33.3% (21/63) at day 6, and 22.2% (14/63) on day 7 post detection. Overall, Omicron infections featured a mean duration of 9.87 days (95% CI 8.83-10.9) relative to 10.9 days (95% CI 9.41-12.4) for Delta infections. The peak viral RNA based on Ct values was lower for Omicron infections than for Delta infections (Ct 23.3, 95% CI 22.4-24.3 for Omicron; Ct 20.5, 95% CI 19.2-21.8 for Delta) and the clearance phase was shorter for Omicron infections (5.35 days, 95% CI 4.78-6.00 for Omicron; 6.23 days, 95% CI 5.43-7.17 for Delta), though the rate of clearance was similar (3.13 Ct/day, 95% CI 2.75-3.54 for Omicron; 3.15 Ct/day, 95% CI 2.69-3.64 for Delta). Conclusions. While Omicron infections feature lower peak viral RNA and a shorter clearance phase than Delta infections on average, it is unclear to what extent these differences are attributable to more immunity in this largely vaccinated population or intrinsic characteristics of the Omicron variant. Further, these results suggest that Omicron's infectiousness may not be explained by higher viral load measured in the nose and mouth by RT-PCR. The substantial fraction of individuals with Ct values <30 at days 5 of infection, particularly in those detected due to symptom onset or concern for contact with an infected individual, underscores the heterogeneity of the infectious period, with implications for isolation policies.