Reading Aloud without a Mask, Olfactory Bulbs, Omega Variant

Here's the latest alarming COVID news to distract you from fires and hurricanes.
{I'm very sorry if you are experiencing either of these disasters personally. Donations ideas: El Dorado Community Foundation and The Mutual Aid Response Network.}

Caldor Fire: Karl Mondon/Bay Area News Group. Hurricane Ida: Edmund D. Fountain/New York Times.

 

Masklessness

Outbreak Associated with SARS-CoV-2 B.1.617.2 (Delta) Variant in an Elementary School — Marin County, California, May–June 2021

An unvaccinated elementary school teacher was experiencing nasal congestion and fatigue but continued working. The teacher read aloud to the students while maskless and two days later received a positive test for the Delta variant. Half of the class was infected, with the greatest risk among those sitting in front. Transmission to siblings and parents ensued, for a total of 27 cases.

"Among the five infected adults, one parent and the teacher were unvaccinated; the others were fully vaccinated. The vaccinated adults and one unvaccinated adult were symptomatic with fever, chills, cough, headache, and loss of smell."

 

The CDC created a figure showing the seating chart, transmission pattern, and whether the individual was symptomatic. The desks were six feet apart, an air filter in front, and the door and windows were open. All five children in the front row were infected.

 

from the CDC: Classroom layout and seating chart for 24 students in index patient’s class, by SARS-CoV-2 testing date, result or status, and symptoms—Marin County, California, May–June 2021

Conclusion and recommendation:

"Ineligibility because of age and lack of vaccination contribute to persistent elevated risk for outbreaks in schools, especially as new SARS-CoV-2 variants emerge. However, implementation of multiple prevention strategies within schools can mitigate this risk."

Olfactory Bulbs 

Speaking of smell, over 20 papers show MRI signal abnormalities in the olfactory bulbs of COVID-19 patients with anosmia (loss of smell). This isn't new, but anosmia has been reported in breakthrough cases as well. The images below show some resolution in a patient from time 1 to time 2.

Magnetic Resonance Imaging Alteration of the Brain in a Patient With Coronavirus Disease 2019 (COVID-19) and Anosmia

"...we can speculate that SARS-CoV-2 might invade the brain through the olfactory pathway and cause an olfactory dysfunction of sensorineural origin."

 

modified from Fig 2 (Politi et al., 2020). A coronal 2-dimensional FLAIR image shows a slight reduction of the hyperintensity and the thickness of the olfactory bulbs [right side], suggesting a postinfection olfactory loss.

modified from Fig 2 (Politi et al., 2020). FLAIR image showing complete resolution of the previously seen signal alteration within the cortex of the right gyrus rectus [bottom image].

Omega Variant 

OK, I made that up. However (alpha, beta, delta, epsilon, iota, gamma, OTHER):

Differing variant distributions between vaccinated breakthrough and unvaccinated caseshttps://t.co/lW1vfRWPls pic.twitter.com/ehY9QONJpU

— Charles Chiu (@cychiu98) August 26, 2021

Predominance of antibody-resistant SARS-CoV-2 variants in vaccine breakthrough cases from the San Francisco Bay Area, California (preprint):

"These findings suggest that vaccine breakthrough cases are preferentially caused by circulating antibody-resistant SARS-CoV-2 variants, and that symptomatic breakthrough infections may potentially transmit COVID-19 as efficiently as unvaccinated infections, regardless of the infecting lineage."