IDPH updated its data today showing there are 42 known cases in Illinois of the COVID-19 variant B.1.1.7, which is the one first discovered in the U.K. There is still only one confirmed case of the variant B.1.351, which originated in South Africa.

A recent study found that the U.K. variant is more contagious and more likely to lead to hospitalizations and deaths. Despite the progress in containing COVID-19 in the State, everyone is encouraged to double mask and maintain social distances.

Risk of Community Spread

Both the CDC and IDPH recommend that communities assess the risk that COVID-19 will spread using two measures: 1) the total number of new COVID-19 cases per 100,000 people in the community (e.g., county) in the past seven days; and 2) the percentage of tests for COVID-19 that were returned positive in the last 7 days. [1, 2 and 3]

For total cases in the last 7 days per 100,000 people, IDPH uses a target of 50 cases. CDC says between 10 and 49 cases represents a “moderate” risk of transmission.

For test positivity in the last 7 days, IDPH uses a target of 5%. CDC says between 5% and 7.9% represents a “moderate” risk of transmission.

Two of the charts in the above chart box track these two measures for Evanston, Suburban Cook County, Chicago and the State. [4] The third chart shows the trend of new cases in the State.

Evanston

There were 11 new confirmed COVID-19 cases of Evanston residents today, up from 7 yesterday.

The average number of new cases per day in the last seven days is 9.7, down from the seven-day average of 13 on Feb. 11. For purposes of comparison, on Oct. 12, the seven-day average was 5.6.

There has been a total of 3,807 COVID-19 cases of Evanston residents during the pandemic, 202 of which are active.  

In the last seven days, there was a total of 68 new COVID-19 cases of Evanstonians. That equates to about 90 new cases per 100,000 people in the seven-day period.

The case positivity rate over the last seven days is 0.8%.

No Evanstonian died due to COVID-19 in the last 72 hours. The number of deaths due to COVID-19 remains at 110.   

Today, the City reported a total of 339 tests, with an average of 1,219 tests per day in the last seven days. The high number of tests is likely due to testing of Northwestern University students, which is likely pulling down Evanston’s test positivity rate.

Impact of Northwestern University. Northwestern University has posted data on its website reporting that between Feb. 11 and Feb. 17 there were 46 new confirmed COVID-19 cases of faculty, staff, and students. The number includes those who live outside of Evanston. The City claims it does not know how many of these cases are people who live in Evanston. [5]

Illinois

 In the State, there were 1,966 new COVID-19 cases reported today.  

Statewide, the average number of new cases per day in the last seven days is 1,836. The seven-day average one week ago, on Feb. 11, was 2,610, so today’s number is a decrease of 30%.  

Today’s seven-day average is down from an all-time high of 12,380 on Nov. 17. An accompanying chart shows the trend.

In the seven days ending Feb. 18, the number of new cases per 100,000 people in the State was 101, down from 144 one week ago.

The seven-day case positivity rate for the State today is 2.7% and the test positivity rate is 3.3%.

On a Statewide basis, the number of hospitalizations due to COVID-19 was 1,655 as of midnight on Feb. 17. This is down from an all-time high of 6,171 on Nov. 23.

The number of patients using ICU beds is 386, down from 1,195 on Dec. 1. The number of patients on ventilators is 184, down from 724 on Dec.  1.

On a Statewide basis, there were 72 deaths due to COVID-19 in the last 24 hours, which brings the total to 20,129.

For the last seven days, the numbers of deaths in the State are 32, 53, 35, 41, 32, 24, and 72 today. The seven-day average is 41.

Vaccines

A total of 2,552,000 doses of vaccine have been delivered to providers in Illinois, including Chicago and long-term care facilities.  IDPH is currently reporting that a total of 1,977,033 doses of vaccines have been administered.

FOOTNOTES 

1/ On Feb. 12, the CDC issued a “K-12 School Operational Strategy.” As part of that strategy, the report says, “CDC recommends the use of two measures of community burden to determine the level of risk of transmission: 1) the total number of new cases per 100,000 persons in the past 7 days; and 2) the percentage of nucleic acid amplification tests (NAATs), including RT-PCR tests that are positive during the last 7 days. The two measures of community burden should be used to assess the incidence and spread of SARS-CoV-2 in the surrounding community (e.g., county) and not in the schools themselves.” The CDC provides a chart to assess whether the risk of transmission is low, moderate, substantial, or high. The CDC recommends different types of mitigations depending on the risk level. If the two indicators suggest different levels of risk, the mitigations recommended in the higher level of risk should be implemented, says CDC. The table below, reprinted from CDC’s report, provides CDC’s Indicators and Thresholds for Community Transmission of COVID-219.

 2/ Number of Cases per 100,000 Population. On July 1, a network of research, policy and public health experts convened by Harvard’s Global Health Institute and Edmond J. Safra Center published a Key Metrics for COVID Suppression framework that provides guidance to policy makers and the public on how to target and suppress COVID-19 more effectively across the nation. The targets for new COVID-19 cases per 100,000 people are as follows (these are converted from cases per day to cases per week): a) less than 7 cases: “on track for containment;” b) 7 to 63 cases: “community spread,” rigorous test and trace program advised; c) 70 to 168 cases: “accelerated spread,” stay-at-home orders and/or rigorous test and trace programs advised; and d) 169+: ”tipping point,” stay-at-home orders necessary.  The article is available here: https://globalepidemics.org/key-metrics-for-covid-suppression/

IDPH provides these categories and ratings: 1) “minimal” – fewer than 50 cases per 100,000 in a week; 2) “moderate” – between 50 and 100 cases per week; and 3) “substantial” more than 100 cases per 100,000 in a week.  In its Metrics for School Determination of Community Spread, IDPH says the “target” is 50 cases per week per 100,000 people.

3/ The Test Positivity Rate. In addition, on May 26, Johns Hopkins University & Medicine Coronavirus Resource Center said on its website that “the World Health Organization (WHO) advised governments [on May 15] that before reopening, rates of positivity in testing (i.e., out of all tests conducted, how many came back positive for COVID-19) should remain at 5% or lower for at least 14 days.”  Link: https://coronavirus.jhu.edu/testing/testing-positivity

The Harvard Global Health Institute (HGHI) says, “A network of research, policy, and public health organizations convened by Harvard and MIT called the TTSI Collaborative has agreed on a 3% test positive rate or below as a key indicator of progress towards suppression level testing.”

IDPH says the test positivity target is 5% or less. IDPH provides these categories and ratings: 1) “Minimal” – test positivity rate is equal to or less than 5%: 2) “Moderate” – test positivity rate is between 5% and 8%; and 3) “Substantial” – test positivity rate is over 8%. In its Metrics for School Determination of Community Spread, IDPH says the target is 5%.

4/ Calculations. The RoundTable calculates the number of cases per 100,000 using case data provided by IDPH and assuming that the population of Suburban Cook County is 2.469 million, that the population of Chicago is 2.710 million, and that the population of Illinois is 12.671 million.

5/ Northwestern University COVID-19 Cases. Ike C. Ogbo, Director of Evanston’s Health & Human Services Department, told the RoundTable that the COVID-19 cases reported by the City include cases of faculty, staff, and students attending Northwestern University who live in Evanston. The RoundTable asked the City in an FOIA Request to provide the number of NU students who tested positive for COVID-19 and who live in Evanston. The City refused to provide the data. On Oct. 26, the RoundTable appealed the City’s decision to the Public Access Counselor of the Attorney General’s Office. On Nov. 13, the City filed a response claiming it does not have any records showing the number of NU students who tested positive for COVID-19 and who live in Evanston.

The RoundTable has asked Northwestern University on several occasions to provide information breaking out the number of new COVID-19 cases of its faculty, staff and students by residency in Evanston. NU did not respond.