Questions About Test Positivity

I think I’ve mentioned before that I think of one type of post that I write as “musing”. In such a post I’m wondering about something. I guess this post is musing. This morning this report from the Chicago Sun-Times filled me with questions:

As the fight continues over the safe reopening of Chicago Public Schools in the midst of a raging public health crisis, the Chicago Teachers Union has released for the first time a list of demands it wants met before members return to schools, including lower COVID-19 test positivity rates, testing and vaccination protocols and changes to both hybrid and remote learning.

Some of the demands are likely to face strong and immediate rejection by city officials who have been adamant that it’s up to them to decide how and when the nation’s third-largest school district will return to classrooms for the first time since March.

This demand caught my attention in particular:

The CTU is also demanding clear public health criteria for opening and closing schools and is proposing a 3% test positivity threshold. Schools would reopen citywide for all students and staff if the rate is lower, and would close if it’s higher, the union said, with community-by-community decisions also possible if rates vary. The city’s seven-day rolling average stood at 13.1% Thursday.

That just filled me with questions. Do I not understand what the “test positivity rate” means? Will we see a test positivity rate of 3% for the foreseeable future? Will the COVID-19 vaccinations increase or decrease test positivity rates? Does that depend on the type of vaccination? Could the effect of heeding the CTU’s demands be to abolish the Chicago Public Schools?

4 comments… add one
  • PD Shaw Link

    CTU is demanding standards more stringent than State guidance, which treats weekly test positivity of 5% and below as minimal community spread. If its above 5%, but 8% or lower, then its moderate. Above 8% its substantial. The guidance isn’t entirely clear what schools should do at various levels, but they are supposed to have a plan in each instance.

    Chicago does not appear to have ever had a 3% positivity rate, so CTU does not want to open this year.

    https://www.dph.illinois.gov/countyschool?county=Chicago

  • PD Shaw Link

    I can easily see vaccination changing the population getting tested, as people vaccinated are essentially removed from the population and the survivors may reflect a different group. Note that the State does not consider certain types of tests to begin with, for example, the U of I mass testing program.

  • Chicago does not appear to have ever had a 3% positivity rate, so CTU does not want to open this year.

    It sounds to me as though they don’t want to open ever.

  • Grey Shambler Link

    The members of the CTU have little to no interest in the education or future of Chicago’s children.
    Their relationship compares to the cons and the screws @ Joliet.
    I would not be surprised if CTU has other demands than safety.
    Namely pension increases and possibly hazardous duty pay.

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