Sept 15, 2021: COVID Weekly Update

It might be a good time to review variants before the weekly data update. Below are summaries of how the CDC classifies variants, which are considered variants of interest and variants of concern, and some information on the Delta and Mu variants.

Update on Variants

Understanding Variants:

  • Viruses constantly change through mutations & variants emerge — disappear or persist
  • The more the virus spreads, the more chances to change.
  • Changes can be monitored by comparing physical traits (ability to spread, resistance to vaccines or treatments) & genetic code (mutations).
  • Scientists can often predict whether a variant is more dangerous than others.

CDC Variant Classifications:

  • Variants of Interest (VOI):  Eta, Iota, Kappa
    • Genetic markers predicted to affect transmission, diagnosis, treatments & immune escape (previous infection or vaccine)
    • Evidence that it’s causing an increase in cases
    • Limited prevalence or expansion in the US or other countries
  • Variants of Concern (VOC):  Alpha, Beta, Delta, Gamma
    • Evidence of impact on diagnostics, treatments, or immune escape
    • Evidence of increased ability to spread
    • Evidence of increased disease severity
  • Variants of High Consequence:  none to date
    • Demonstrated failure of diagnostic tests
    • Significant reduction in the effectiveness of vaccines & treatments
    • More severe clinical disease & increased hospitalizations

Delta Variant (VOC):

  • Spread:  Much faster than other variants
  • Severe illness & death:  May cause more severe cases than other variants
  • Vaccine: 
    • Infections happen in only a small proportion of people fully vaccinated
    • Fully vaccinated people can spread the virus to others
    • All vaccines effective against severe illness, hospitalization & death
  • Treatments:  certain monoclonal antibody treatments are less effective against the Delta variant

Mu Variant:

  • Classified as a variant of interest by the World Health Organization on August 30th, but not yet the CDC
  • Has potential properties of immune escape – needs to be confirmed
  • Globally, the prevalence of this variant has declined
  • CDC is monitoring, not considered an immediate threat due to low prevalence


Weekly Updates

It’s probably worth the time to look over the attached slides – a lot of important trends right now.

Brookings County (highest level of spread)

  • 4,708 total cases:  126 new cases this week (high spread) vs. 70 in the previous week:
    • 51 (40%) were under 20 years of age (vs. 28% last week)
    • 44 (35%) were 20-39 years (vs. 52% last week)
    • 20 (16%) were 40-59 years (vs. 15% last week)
    • 11 (9%) were 60 years or older (vs. 5% last week)
  • Since August 25th, the largest increase in percentage of cases has been in the 0-9 year (16% increase) and 10-19 year (10% increase) age groups.  The largest increase in number of cases has been in the 20-29 year age group (n=92).
  • 233 active cases (187 last week)
  • Test positivity (PCR) this past week was 11% compared to 9% last week.  Ideally, you want this below 5%, and the lower, the better.  A high percentage indicates there are likely many more cases out there – get tested if you have been exposed or have symptoms.
  • There were no new hospital admissions among Brookings County residents in the past week vs. 2 in the previous week.  Brookings Hospital currently has no COVID hospitalized patients.  In Sioux Falls, Avera has 26 COVID-occupied beds (12 ICU) and Sanford has 44 (11 ICU).
  • There were no new deaths reported among Brookings County residents this past week. 
  • The percentage of people vaccinated did not increase much this past week, with 44% of Brookings County fully vaccinated vs. 43% of South Dakotans (similar percentages as last week).

South Dakota (highest level of spread)

  • 138,860 cases: 3,322 new cases this week vs. 2,701 in the previous week:
    • 987 (30%) were under 20 years of age (vs. 26% last week)
    • 978 (29%) were 20-39 years (vs. 33% last week)
    • 796 (24%) were 40-59 years (vs. 22% last week)
    • 561 (17%) were 60 years or older (vs. 19% last week)
  • 7,364 active cases (6,570 last week)
  • Test positivity (PCR) this past week was 14% compared to 15% last week.  Ideally, you want this below 5%, and the lower, the better. 
  • 124 residents admitted to in-state hospitals this week vs. 141 last week:  
    • 4 (3%) were aged less than 20 years (vs. 3% last week)
    • 14 (11%) were 20-39 years (vs. 19% last week)
    • 31 (25%) were 40-59 years (vs. 27% last week)
    • 75 (61%) were 60 years of age and older (vs. 51% last week)
  • 204 people currently hospitalized vs. 210 hospitalized last week (58 currently in the ICU vs. 68 last week)
  • 2,093 deaths:  16 deaths reported this week vs. 8 in the previous week: 
    • 1 were 20-39 years
    • 3 were 40-59 years
    • 12 were 60 years of age and older


  • 42.28 million cases:  1.08 million new cases this week vs. 1.09 million in the previous week
  • 682,341 total deaths (vs. 675,000 from 1918 influenza):  13,319 deaths this week vs. 11,112 in the previous week 


  • 226.6 million cases: 3.90 million cases this week vs. 4.21 million in the previous week
  • 4.66 million deaths: 63,198 deaths this week vs. 65,872 in the previous week 

Be kind to yourself & others – get vaccinated, wear a mask when indoors, socially distance, avoid crowds, and practice good personal hygiene.

Published by Bonnysblog78398238

I'm interested in numbers.

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