Population-scale longitudinal mapping of COVID-19 symptoms, behaviour and testing.

Despite the widespread implementation of public health measures, coronavirus disease 2019 (COVID-19) continues to spread in the United States. To facilitate an agile response to the pandemic, we developed How We Feel, a web and mobile application that collects longitudinal self-reported survey responses on health, behaviour and demographics. Here, we report results from over 500,000 users in the United States from 2 April 2020 to 12 May 2020. We show that self-reported surveys can be used to build predictive models to identify likely COVID-19-positive individuals. We find evidence among our users for asymptomatic or presymptomatic presentation; show a variety of exposure, occupational and demographic risk factors for COVID-19 beyond symptoms; reveal factors for which users have been SARS-CoV-2 PCR tested; and highlight the temporal dynamics of symptoms and self-isolation behaviour. These results highlight the utility of collecting a diverse set of symptomatic, demographic, exposure and behavioural self-reported data to fight the COVID-19 pandemic.

Population-scale Longitudinal Mapping of COVID-19 Symptoms, Behavior, and Testing Identifies Contributors to Continued Disease Spread in the United States.

Despite social distancing and shelter-in-place policies, COVID-19 continues to spread in the United States. A lack of timely information about factors influencing COVID-19 spread and testing has hampered agile responses to the pandemic. We developed How We Feel, an extensible web and mobile application that aggregates self-reported survey responses, to fill gaps in the collection of COVID-19-related data. How We Feel collects longitudinal and geographically localized information on users' health, behavior, and demographics. Here we report results from over 500,000 users in the United States from April 2, 2020 to May 12, 2020. We show that self- reported surveys can be used to build predictive models of COVID-19 test results, which may aid in identification of likely COVID-19 positive individuals. We find evidence among our users for asymptomatic or presymptomatic presentation, as well as for household and community exposure, occupation, and demographics being strong risk factors for COVID-19. We further reveal factors for which users have been SARS-CoV-2 PCR tested, as well as the temporal dynamics of self- reported symptoms and self-isolation behavior in positive and negative users. These results highlight the utility of collecting a diverse set of symptomatic, demographic, and behavioral self- reported data to fight the COVID-19 pandemic.

Toxic anterior segment syndrome: common causes.

PURPOSE: To identify the most common risk factors associated with toxic anterior segment syndrome (TASS). SETTING: Ophthalmic surgical centers in the United States, Argentina, Brazil, Italy, Mexico, Spain, and Romania. METHODS: A TASS questionnaire on instrument cleaning and reprocessing and extraocular and intraocular products used during cataract surgery was placed on the American Society of Cataract and Refractive Surgery web site. A retrospective analysis of questionnaires submitted by surgical centers reporting cases of TASS was performed between June 1, 2007, and May 31, 2009, to identify commonly held practices that could cause TASS. Members of the TASS Task Force made site visits between October 1, 2005, and May 31, 2009, and the findings were evaluated. RESULTS: Data from 77 questionnaires and 54 site visits were analyzed. The reporting centers performed 50 114 cataract surgeries and reported 909 cases of TASS. From January 1, 2006, to date, the 54 centers reported 367 cases in 143 919 procedures; 61% occurred in early 2006. Common practices associated with TASS included inadequate flushing of phaco and irrigation/aspiration handpieces, use of enzymatic cleansers, detergents at the wrong concentration, ultrasonic bath, antibiotic agents in balanced salt solution, preserved epinephrine, inappropriate agents for skin prep, and powdered gloves. Reuse of single-use products and poor instrument maintenance and processing were other risk factors. CONCLUSIONS: The survey identified commonly held practices associated with TASS. Understanding these findings and the safe alternatives will allow surgical center personnel to change their practices as needed to prevent TASS. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.