Mass General Brigham researchers have developed a new precision AI tool to identify hidden cases of long COVID from patient medical records. Their new approach was more accurate than tools that look only at diagnostic codes, and found that 22.8% of the population experience symptoms of long COVID, a greater figure than previous estimates that may be less biased and more representative of national trends, according to the study's authors. The researchers plan to release the algorithm publicly where physicans and healthcare systems around the world can test it in their patient populations.

Researchers at the Medical University of Vienna and the Medical University of Innsbruck discovered that SARS-CoV-2 hijacks three important host proteins that dampen the activity of the complement system, a key component of early antiviral immunity. This significantly impairs viral clearance which may affect the course of both acute COVID-19 infections and post-COVID-19 sequelae. The study was recently published in the journal “Emerging Microbes & Infections”.

A review article by researchers at the State University of Campinas and Baylor College of Medicine discusses relationships between these two conditions, identifying biomarkers that can help clinicians make a differential diagnosis.

 

Increased capabilities for genomic surveillance have offered new insights into global viral evolution;

Seasonal flu showed a ‘remarkable’ bounce back to pre-pandemic levels once international air travel resumed;

Regions with fewer COVID-19 restrictions were associated with sustained flu virus transmission.

Although travel restrictions and social measures during the COVID-19 pandemic led to a dramatic global drop in seasonal influenza cases, certain influenza lineages in specific regions kept the virus circulating and evolving, according to a new study. This was true in tropical areas with fewer travel restrictions, for example, including South and West Asia. The spread of seasonal influenza is closely tied to social behavior, particularly air travel, and to the periodic evolution of new virus strains that evade immunity from prior infections or vaccinations. In 2020, nonpharmaceutical interventions (NPIs) introduced to combat COVID-19 – such as lockdown policies, mandated social distancing, masking, and travel bans – dramatically impacted influenza virus transmission and evolution. Due to these interventions, cases of seasonal influenza caused by A subtypes H1N1 and H3N2, as well as influenza B subtypes Victoria and Yamagata, declined sharply across the globe.

 

Here, Zhiyuan Chen and colleagues investigated how these changes affected the spread, distribution, and evolutionary dynamics of seasonal influenza lineages. Using a phylodynamic approach, Chen et al. combined epidemiological, genetic, and international travel data from before, during, and after the COVID-19 pandemic and found that the onset of the pandemic led to a shift in the intensity and structure of international influenza transmission. Although influenza cases significantly dropped globally during the pandemic’s peak, in South Asia and West Asia, regions that had relatively fewer pandemic restrictions, the circulation of influenza A and influenza B/Victoria lineages, respectively, continued. That circulation served as important evolutionary sources, or “phylogenetic trunk locations,” of influenza viruses during the pandemic period. By March 2023, as global air traffic resumed, the circulation of influenza lineages returned to pre-pandemic levels, highlighting the virus’ resilience to long-term disruption and its reliance on global air travel patterns to spread. Notably, however, the findings also show that the influenza B/Yamagata lineage appears to have disappeared since the start of the pandemic, suggesting that the lineage may have since gone extinct. “The study by Chen et al. further reinforces that nonpharmaceutical interventions can be incredibly effective in disrupting viral transmission, pathogen diversity, and antigenic evolution, and are arguably more effective than vaccine efforts alone,” write Pejman Rohani and Justin Bahl in a related Perspective.

About The Study: In this longitudinal cohort study of multiple aspects of child neurodevelopment between ages 6 and 24 months, negligible associations between prenatal exposure to SARS-CoV-2 infection and child outcomes were observed. Follow-up research is warranted to determine whether these predominantly null effects persist into later childhood.