October 16: Increase continues.
Daily Status, October 16
The trends over the last three weeks, now are showing a modest increase, at 2.2%/per day or 16% per week.
By combining our current regional trends with the typical reporting for the day of the week, I expect 1360 cases tomorrow (Thursday) with a 90% chance of the numbers falling between 921 - 2016 cases. If tomorrow's numbers differer from that, we are having a very rare event. This is useful to consider if I am unable to report tomorrow, as you can compare the state reported numbers with this.
Regionally, all districts showing positive case growth. The testing numbers now show the percent positive to below the 5% metric over the last week (4.88%) that is often used to indicate sufficient testing (e.g., is is safe to reopen schools). Virginia is testing about 2.8% of the population every two weeks, which is about 1/4th the number of tests desired for random sampling, but most of the Commonwealth's testing is driven by medical needs and not surveillance. Surveillance would ideally test at least 5% of the population per week but the testing is somewhat invasive..
On one other front, over the last week, we well above 10 cases per 100,000 to enter states like NY without quarantine -- we are at nearly 13 cases per 100K. As expected NY added us back on the quarantine list.
Outside of a multiple smaller cities/towns, the state is doing better than it has since the Hampton Roads surge except we are seeing more localized outbreaks; the hot spots are isolated and probably associated with facility outbreaks. Also, looking at the chance of being exposed in a group of 50 (e.g, eating at a restaurant), while almost all of the state is blue or clear, the teal to yellow regions (dangerous) are increasing.
But, looking at the weekly numbers, it appears that the rural areas, whose caseloads were already increasing, surged with the the influx of a carefree demographic (college students). I think we area so seeing some impact of the White House outbreak, as many employees live in northern VA. This is mostly showing up in the Upper Middle Class suburbs.
NOVA: 1.024-- GMU
Central VA: 1.024 -- VCU
Hampton Roads/Eastern VA: 1.016-- W&M, CNU & ODU
SW VA: 1.029-- VT & Radford
NW VA: 1.011 -- JMU & UVA
The state as a whole is is increasing with Rt=1.0215
The following table shows the number per 100k for each region. Again, NOVA and Eastern VA are doing the best, and the mountainous regions in NW & SW continue having more cases. The concerning aspect is in all regions, the numbers for last week are significantly higher than the prior 3 weeks. What is most concerning is SW &NW VA, where it is hitting very high numbers, inspite of VT and Radford doing better.
(replace the numbers above the the numbers below)
The following charts are for the 5 regions. in the chart that shows all regions, The individual line charts show the unfiltered data per day, coupled with the trend lines. The trend lines show the different periods of growth. Early in the pandemic, the different parts of Virginia were functioning largely independently, with NOVA mimicking the northern states, and Hampton Roads mimicking the southern states. But, since September 1, the regions have trended with each other. Starting in late Sept., NoVA and SWVA diverged from the rest of the state. The increase in NoVA amounts to a total of about 750 extra cases, which may be too many to attribute to the 9/26 White House event.
Note that the effects at both ends of the chart are probably an artifact of the 7-day polynomial filtering I use. The filter is called a Savitzky-Golay filter, and basically is a moving window polynomial filter. At the edge (first and last days of the time series), the filter will over compensate for the trend.
Growth rate (%/day)
Last 10 days
% that had COVID***
* estimated from the number of cases in the zip codes associated with the university removing the pre-student arrival case rate
Large Scale Community Spread:
- People can test negative and still spread the disease.
- Even if everyone who interacts with you is tested immediately prior to the interaction, you can still get sick (see 1).
- If you have an event with hundreds of people, there is potential for it to be a super-spreader event, even if you test everyone at the event.
- If you do this frequently enough, you will get unlucky.
- A non-spaced, but outside event is still dangerous.
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Other Sites: John's Hopkins
Kids can pass covid to parents: Pediatric SARS-CoV-2: Clinical Presentation, Infectivity, and Immune Responses