A Hierarchical Framework for Assessing Transmission Causality of Respiratory Viruses

Systematic reviews of 591 primary studies of the modes of transmission for SARS-CoV-2 show significant methodological shortcomings and heterogeneity in the design, conduct, testing, and reporting of SARS-CoV-2 transmission. While this is partly understandable at the outset of a pandemic, evidence rules of proof for assessing the transmission of this virus are needed for present and future pandemics of viral respiratory pathogens. We review the history of causality assessment related to microbial etiologies with a focus on respiratory viruses and suggest a hierarchy of evidence to integrate clinical, epidemiologic, molecular, and laboratory perspectives on transmission. The hierarchy, if applied to future studies, should narrow the uncertainty over the twin concepts of causality and transmission of human respiratory viruses. We attempt to address the translational gap between the current research evidence and the assessment of causality in the transmission of respiratory viruses with a focus on SARS-CoV-2. Experimentation, consistency, and independent replication of research alongside our proposed framework provide a chain of evidence that can reduce the uncertainty over the transmission of respiratory viruses and increase the level of confidence in specific modes of transmission, informing the measures that should be undertaken to prevent transmission.     

Open ring enhancement in atypical brain demyelination

Open ring enhancement is considered highly specific for atypical demyelination. In this report we present a patient with a history of headache, ataxia and sensory disturbances in the lower extremities. A cranial MRI scan showed a large frontal lesion with mass effect, midline shift and with open ring enhancement. These findings are characteristics of tumefactive multiple sclerosis. Such lesions can be confused with neoplasms and abscesses. Open ring enhancement may help in differentiating atypical demyelination from a neoplasm or an abscess.     

A rare case of pediatric pancreatic pseudocyst

We present a case report of a 2‐year‐old boy who presented to a local hospital to evaluate vague abdominal symptoms of one‐month duration. The patient, therefore, had an open cystogastrostomy and drainage of the free abdominal fluid with minimal complications. He was monitored for several days after his surgery.     

Myxedema Coma and Hypoventilation

Carbon dioxide retention may underlie many treatment failures in myxedema. Exactly why myxedematous patients hypoventilate is unclear. Possible causes of the ineffective breathing are many and include obesity and central nervous system dysfunction. Quick action to improve respiratory function can gain valuable time. In the case reported here, respiratory assistance was lifesaving.