COVID-19: Asymptomatic Disease Prevalence / N95 Mask Reuse / Oxygen Management Strategies / Anti-Racism Demonstrations / Studies Retracted

By Kelly Young

Edited by André Sofair, MD, MPH, and William E. Chavey, MD, MS

Here is some of the latest news on COVID-19:

Prevalence of asymptomatic disease: An estimated 40–45% of people who test positive for SARS-CoV-2 do not have symptoms at the time of testing, according to a narrative review of 16 cohorts in the Annals of Internal Medicine. In four cohorts with longitudinal data, few of the asymptomatic patients (0–10%) went on to develop symptoms. But in one skilled nursing facility, 89% of initially asymptomatic patients became sick. The researchers say, "It is imperative that testing programs include those without symptoms." They add, "The early data that we have assembled on the prevalence of asymptomatic SARS-CoV-2 infection suggest that this is a significant factor in the rapid progression of the COVID-19 pandemic."

N95 mask reuse & failure rates: A small, cross-sectional study in JAMA reports that duckbill N95 masks had a high rate of fit test failure (71%) among healthcare workers who were using their masks for extended periods. Dome-shaped N95 masks had a 28% failure rate. For the dome-shaped masks, failure was more likely with increasing duration of use. The authors of the research letter write: "Based on these preliminary data, health systems should closely evaluate N95 fit during extended use or reuse and limit duckbill mask use if alternatives are available."

Oxygen management strategies: A variety of noninvasive oxygen administration strategies were compared for acute hypoxemic respiratory failure (AHRF) in a JAMA network meta-analysis. Researchers examined 25 randomized controlled trials that compared various oxygen management strategies among some 3800 patients with AHRF (but without COVID-19). Helmet noninvasive ventilation conferred lower risks for mortality and endotracheal intubation, compared with high-flow nasal oxygen, face mask noninvasive ventilation, and standard nasal oxygen. Face mask noninvasive ventilation was also associated with decreased risks, compared with standard nasal oxygen. Editorialists write that the study can "help inform clinicians as they determine locally the best way to choose wisely among several options for care of patients with AHRF, especially in the wave of patients with COVID-19 currently being encountered. ... In the management of heterogeneous syndromes like AHRF, it is better to have multiple options than to focus on limiting clinical practice to a single choice."

Anti-racism demonstrations amid COVID-19: Over 1000 public health officials, infectious disease experts, and community members have signed an open letter on strategies for a public health response to the recent demonstrations against systemic racism amid the COVID-19 pandemic. They oppose use of tear gas and other respiratory irritants. Face coverings during protests should be encouraged, and access to testing after demonstrations should be increased.

Studies retracted: Two studies in the New England Journal of Medicine and the Lancet have been retracted because they relied on a Surgisphere database, which has come under scrutiny. The NEJM study examined the relationship between hypertension drugs and mortality in COVID-19 patients, while the Lancet study looked at whether hydroxychloroquine and chloroquine were effective COVID-19 treatments. Three of the authors of the Lancet article say that Surgisphere declined to transfer the full dataset and other material to a team of independent reviewers.