· What was the SARS-CoV-2-specific neutralizing antibody response in Norwegian healthcare workers after the first wave of COVID-19 pandemic? A multicenter prospective survey study of 607 healthcare workers (HCW) by a researcher at the Influenza Centre at the University of Bergen in Norway found 5% of participants (32/607) were seropositive for SARS-CoV-2 (spike-specific IgG, IgM, and IgA antibodies), including 21 who were positive at baseline and 11 who seroconverted during follow-up. 77% of the infected HCWs, in high-risk departments were young nurses aged 23-31. Results also showed that HCW were 11.6 times more likely to contact COVID-19 patients when compared to low-risk HCW or community members, while HCW with partial PPE were at a 2.5 fold higher risk. Authors highlight the importance of protecting high-risk frontline HCW and suggest prioritization of this group during vaccine distribution.
· COVID-19 did not appear to have drastic effects on the pregnant population. Researchers affiliated with Department of Obstetrics and Gynecology at University of Toronto, Canada conducted a literature review of 8 studies including 10,966 patients in 15 countries on COVID-19 in pregnancy and found that maternal characteristics, symptoms, and outcomes were not significantly different from the general population. They hypothesize pregnancy-induced changes to the ACE-2-Angiotensin axis might counteract changes induced by SARS-CoV-2, leading to less vasoconstriction, fibrosis, and inflammatory/thrombotic processes. Authors suggest pregnant women may not be more affected by SARS-CoV-2 infection than the general public, but urge for further research due to paucity of data on aggressiveness of COVID-19 in pregnancy.
Understanding the Pathology
· Could there be an association of salivary content alteration and early ageusia symptoms in COVID-19 infections? Dental specialists in Saudi Arabia reviewed 36 studies on chemical and inflammatory changes that occur in SARS-CoV-2 infected salivary glands and propose a chemosensory mechanism to explain alterations in taste and smell found commonly seen in COVID-19. In patients reporting aguesia, they found changes in salivary hormones, inorganic compounds, pH, enzymes, and salivary flow rate, which are all involved in normal taste perception. Authors suggest with better understanding and characterization of these changes, we may be able to prevent or treat changes in smell or taste seen among COVID-19 patients.
Transmission & Prevention
· Specific occupations and risk of severe COVID-19 are positively correlated. In this large-scale prospective cohort study, authors from various public health institutes in Glasgow, UK, Limerick, Ireland, and Syracuse, NY, analyzed data from the UK Biobank, involving 120,075 participants aged 40-69 registered with the National Health Service (NHS) in England, Wales or Scotland, and grouped them into occupational groups with concomitant serious COVID-19 infection (having to be hospitalized), in order to asses risk of infection across essential occupations. They found 29.3% of participants were classified as essential workers (9% healthcare, 11.2% social and education, and 9.1% other essential workers), and that 3,111 (2.6%) of the total participants tested positive for SARS-CoV-2. They concluded healthcare workers were at a 7-fold increased risk of developing severe COVID-19 and that social and transport workers had a doubled risk, highlighting the need for better protection and support for workers at higher risk for infection.
· There may be a high prevalence of pulmonary sequelae at 3 months after hospital discharge in mechanically ventilated COVID-19 survivors. In this letter to the editor, Dutch researchers share their clinical data from 48 critically-ill COVID-19 patients who underwent follow-up screening three months after discharge that included pulmonary function testing (PFT), high resolution chest CT (HRCT), and 6-minute walk test (6-MWT). Prominent findings included diminished diffusion capacity, total lung capacity, and reticular fibrosis with ground-glass opacities present on HRCT. They report some evidence of new emphysematous abnormalities on HRCT which may be novel for COVID-19 compared to SARS or MERS. These findings suggest the necessity for intensive respiratory follow-up for patients with COVID-19 who underwent mechanical ventilation to screen for pulmonary sequelae.
R&D: Diagnosis & Treatments
· There is some data suggesting usage of smartwatch tracking data to detect COVID-19 cases early. An article reviews a study conducted by researchers at Scripps Research Translational Institute who compared the smartwatch data between 333 participants, 54 of which ended up reporting positive for COVID-19, and found that symptom tracking plus smartwatch biometric data collecting yielded more predictive results of COVID-19 positive test probability than symptom tracking alone. This study was conducted earlier this year and used a smartphone/smartwatch app called DETECT.
· Delayed specific IgM antibody responses observed among COVID-19 patients with severe progression. Virologists and immunologists from China and Canada analyzed the diagnostic accuracy of RT-qPCR testing compared to IgM-based antibody testing for COVID-19. They found IgM-based gold immunochromatographic assay (GICA) detected 82.2% (n=37/45) of RT-qPCR confirmed COVID-19 cases and 32.0% (n=8/25) of clinically suspected patients who falsely tested negative by RT-qPCR (Figure 1).Interestingly, 50% (n=4/8) of patients who were IgM-negative and RT-qPCR-positive developed severe disease (Figure 2). Researchers concluded that IgM-based antibody testing may have a complementary role to RT-PCR in diagnosing active infection by reducing false negatives, and delayed IgM antibody response may be predictive of more severe disease progression.