High blood viscosity tied to greater risk of death in hospital COVID patients
High estimated blood viscosity (eBV) is significantly associated with greater risk of death from complications among hospitalized COVID-19 patients, suggests a retrospective study published yesterday in the Journal of the American College of Cardiology.
A team led by researchers from the Icahn School of Medicine at Mount Sinai in New York City analyzed the eBV and outcomes of 5,621 hospitalized COVID-19 patients with lab results available within 24 hours of diagnosis from Feb 27, 2020, to Nov 27, 2021. Viscosity is a measure of a fluid's resistance to flow, so higher BV means the heart works harder to pump blood.
Both high-flow (eg, in the arteries) and low-flow eBV (eg, in smaller blood vessels) were linked to respective 60% and 32% higher rates of in-hospital death. Each 1-centipoise (BV unit) increase in high- and low-flow eBV was associated with a 36% and 7% rise in death rate, respectively.
Relative to patients in the lowest quartile of high-flow eBV, those in the highest quartile had 53% higher death rates (adjusted hazard ratio [aHR], 1.53; 95% confidence interval [CI], 1.27 to 1.84). The link was observed across multiple subgroups, particularly among those without underlying illnesses (aHR, 1.69; 95% CI, 1.28 to 2.22).
The researchers noted that high BV induces injury to the membrane lining the inside of the heart and blood vessels and raises the risk of blood clots. Identifying at-risk patients soon after diagnosis could enable early administration of blood thinners, fluids, or intensification of glucocorticoid therapy.
"This study demonstrates the importance of checking for blood viscosity in COVID-19 patients early in hospital admission, which is easily obtained through routine lab work," senior Robert Rosenson, MD, said in a Mount Sinai news release.
In a related commentary, Italian researchers Aldo Bonaventura, MD, PhD; and Nicola Potere, MD, said that research into the prognostic role of eBV in outpatients and long COVID patients is also urgently needed. "BV may also represent a novel therapeutic target in COVID-19, which certainly deserves additional attention, and it could generate relevant therapeutic implications for, but not limited to, COVID-19," they wrote.
Jul 18 J Am Coll Cardiol abstract and commentary
Jul 18 Mount Sinai news release
Sporadic avian flu outbreaks continue in US and Europe
The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) recently reported two more highly pathogenic avian flu outbreaks in poultry, and Germany and Poland reported more H5N1 avian flu outbreaks in poultry.
In the United States, the latest avian flu outbreaks occurred at a backyard facility that keeps 60 poultry in Oregon's Deschutes County. Also, the virus was detected at a commercial turkey farm in Utah's Sanpete County, affecting 15,500 birds. The new events bring US poultry losses to more than 41.1 birds across 37 states.
In Europe, Germany on Jul 16 reported a new H5N1 event at a commercial fattening farm housing geese and chickens in Schleswig-Holstein state in the northwest. The virus killed 2,000 of 13,500 birds. Also, Poland today reported a new H5N1 outbreak in poultry, which struck a commercial farm in Wielkopolskie province in the west-central part of the country. Of 39,856 susceptible birds, the virus killed 2,468.
USDA APHIS poultry outbreak updates
Jul 16 OIE report on H5N1 in Germany
Jul 19 OIE report on H5N1 in Poland
Flu levels stabilize in most global regions
In its latest global flu update, which covers the last half of June, the World Health Organization (WHO) said the level of virus activity has stabilized after dropping from a March peak.
Activity appears to have plateaued in the temperate Southern Hemisphere countries following increasing levels there. Tropical regions South America and Africa also reported decreasing or low activity.
Flu activity increased, however, in Southeast and East Asia, particularly in southern China. Overall, influenza A made up 98.4% of global samples, and, of subtyped influenza A, 96.4% were the H3N2 strain.
"In the countries of North America, influenza activity decreased compared to the previous period, and influenza positivity was close to levels typically observed at this time of year," the WHO said. "In Canada, influenza-like illness (ILI) activity and paediatric influenza-associated hospitalizations remained above expected levels for this time of year. Influenza activity of predominantly A viruses decreased to below the seasonal threshold. In the USA, ILI remained below the national baseline."
Jul 11 WHO update