Coronastream: CT-imaging COVID-19, outcomes in type II diabetes and hand sanitizer
Posted on May 11, 2020 by Dr Tim Inglis
In this special blog series, medical microbiologists led by Dr Tim Inglis summarise some of the research that will be essential to inform COVID-19 countermeasures. Find out more about the project in Professor Inglis' Editorial 'Logic in the time of coronavirus', published in the Journal of Medical Microbiology.
There are enough data at this stage in the COVID-19 epidemic to start populating a cohesive cause and effect narrative: congruence (convergence of molecular biology, clinical features and epidemiology), consistency (reproducible features of this nexus, and its temporal–spatial clustering), cumulative dissonance (upscaling through multiple levels of biological organisation) and curtailment (diagnosis, containment, control and preventive interventions).
Congruence: CT imaging features of COVID-19 pneumonia
Abnormal CT features were mainly on periphery, middle, lower and posterior regions of the lungs, following a time-dependent pattern:
- Early: rapid progression, 1-7 days, ground glass opacities, consolidation, reticular pattern
- Advanced: peak abnormality, 8-14 days, asynchronous absorption and progression
- Late: improvement, > 14 days, abnormalities start to improve
Consistency: How co-morbidities contribute to COVID-19 outcomes (diabetes)
In this observational study of 7,337 cases of COVID-19 from Hubei Province, 952 already had type II diabetes. Diabetic cases had higher mortality and organ system failure. Conversely, well-controlled blood glucose was associated with lower mortality. The implications are that optimal blood glucose control could improve clinical outcomes.
Cumulative dissonance: The role of ACE2 in COVID-19 pathogenesis
This article reviews the key role of SARS-CoV-2 cleaved angiotensin converting enzyme 2 (ACE2) in the pathogenesis of COVID-19, and subsequent development of severe disease. The figures illustrate molecular processes and explain how ACE2 cleaved by TMPRSS2 allows SARS-CoV-2 to enter human cells.
Curtailment: The efficacy of hand sanitizer on SARS-CoV-2
In this analysis of viricidal activity of World Health Organization hand sanitizer in full strength and diluted forms, SARS-CoV-2 was susceptible to the original and modified WHO formulation with a reduction factor (RF) of > 3.8 to > 5.9 and was still effective at a dilution of more than 40%. The method used relied on viral cytopathic effect in Vero cells to determine a 50% tissue culture infectious dose.