I n December 2019, an outbreak of acute respiratory illness secondary to a novel coronavirus (SARS-CoV-2) originated in Wuhan, China. As of May 13, 2020, coronavirus disease 2019 (COVID-19) has caused a global pandemic resulting in more than 4 170 000 cases and over 287 000 deaths. 1 This pandemic has placed immense, and in some cases overwhelming, strain on health care systems around the world. Most people with COVID-19 present initially with a mild illness and do not require hospital admission. 2 These patients are generally discharged home to self-isolation as a means of reducing the burden on the health care system and limiting spread of COVID-19 to other, vulnerable patients and staff in hospital. 3 We expected, however, that, owing to self-isolation requirements, there would be no formal method for physician assessments or counselling to occur in outpatients whose tests subsequently return as positive for COVID-19. The aim of our study was to develop and test the feasibility of a virtual care program for physician assessment and follow-up of outpatients with COVID-19 in self-isolation. Methods Design and setting Sunnybrook Health Sciences Centre is a 627-bed academic tertiary care centre located in Toronto, Ontario. Patients who present to our institution with suspected COVID-19 infection and mild symptoms are sent home to self-isolate while test results are pending. Institutional testing criteria for COVID-19 have evolved throughout the pandemic. Early in the pandemic, criteria for testing focused on patients with respiratory symptoms and a compatible history of travel to a high-risk country within the preceding 14 days. With ongoing local

Glucose transporter (GLUT) proteins play a key role in the transport of monosaccharides across cellular membranes, and thus, blood sugar regulation and tissue metabolism. Patterns of GLUT expression, including the insulin-responsive GLUT4, have been well characterized in mammals. However, relatively little is known about patterns of GLUT expression in birds with existing data limited to the granivorous or herbivorous chicken, duck and sparrow. The smallest avian taxa, hummingbirds, exhibit some of the highest fasted and fed blood glucose levels and display an unusual ability to switch rapidly and completely between endogenous fat and exogenous sugar to fuel energetically expensive hovering flight. Despite this, nothing is known about the GLUT transporters that enable observed rapid rates of carbohydrate flux. We examined GLUT (GLUT1, 2, 3, & 4) expression in pectoralis, leg muscle, heart, liver, kidney, intestine and brain from both zebra finches (Taeniopygia guttata) and ruby-throated hummingbirds (Archilochus colubris). mRNA expression of all four transporters was probed using reverse-transcription PCR (RT-PCR). In addition, GLUT1 and 4 protein expression were assayed by western blot and immunostaining. Patterns of RNA and protein expression of GLUT1-3 in both species agree closely with published reports from other birds and mammals. As in other birds, and unlike in mammals, we did not detect GLUT4. A lack of GLUT4 correlates with hyperglycemia and an uncoupling of exercise intensity and relative oxidation of carbohydrates in hummingbirds. The function of GLUTs present in hummingbird muscle tissue (e.g. GLUT1 and 3) remain undescribed. Thus, further work is necessary to determine if high capillary density, and thus surface area across which cellular-mediated transport of sugars into active tissues (e.g. muscle) occurs, rather than taxon-specific differences in GLUT density or kinetics, can account for observed rapid rates of sugar flux into these tissues.