Covid cases vs. ‘case rates’: How population plays into local numbers

By Cherise Madigan
©2021 Telegraph Publishing LLC

Cases of Covid-19 are continuing to rise in area towns, with Springfield up by 22 to a total of 108 and Manchester up by 27 to 81 in the span of just one week. By comparison, Vermont statewide has experienced has seen its case count rise by 898 in the same week.

The highest town “case rates” in the area are in Londonderry, Weston, Winhall, Manchester and Dover, with each reporting more than 80 cases per 10,000 residents. The Department of Health says that such “case rates” provide the best measure of Covid-19 in a community since they take into account the population size.

As an example, in Chester, the total number of cases stands at 41 as of Jan. 20 (up by 6 from Jan. 13) in a population of 3,154. But, according to “case rates,” Chester falls within the “41 to 80 cases per 10,000” rate.   Here’s a link to the latest map, with the town chart below it.

The state doesn’t report cases from towns with fewer than six cases recorded since March 2020, due to privacy concerns, but the rate of cases per 10,000 people is released each Friday. Exact Covid case numbers counted from the beginning of the pandemic in March 2020 currently are reported for most — 184 — of Vermont’s 255 towns. Mount Holly and Weston were both added to the town count list in recent weeks having recorded six total cases since March 5.

Weston falls into the “More than 80 cases per every 10,000 people” range on the map due to its small population of 566 and, Health Department spokesman Ben Truman said, and not because there is an “indication of any atypical community spread.”

Between the reports of Jan. 13 and Jan. 20, Londonderry recorded no new cases, after seeing 12 new cases the previous week. It now stands in the “More than 80” cases per 10,000 range in a population of 1,677.  Truman said this can be attributed to a ”very small” increase in cases over the two weeks preceding Jan. 20.

While some locals have questioned whether tourism generated by ski areas in the region could be to blame for increasing rates, Truman says that “there are no ski related outbreaks” in towns with high case counts. “We are aware of a few outbreaks in that region,” he said, “however, none are related to the ski industry.”

Covid-19 Cases by Town

Town	Total Cases as of Jan. 20	Total Cases as of Jan. 13	Increase	Population
Cavendish	14	14	0	1,406
Chester	41	35	6	3,154
Danby	19	16	3	1,311
Dorset	13	8	5	1,944
Dover	57	54	3	1,064
Grafton	7	6	1	679
Jamaica	12	10	2	1,030
Londonderry	34	34	0	1,677
Ludlow	35	33	2	1,885
Manchester	81	54	27	4,258
Mount Holly	7	6	1	1,244
Rockingham	73	71	2	5,282
Springfield	108	86	22	9,373
Weathersfield	34	29	5	2,761
Weston	6	N/A	N/A	566
Winhall	33	26	7	735

Five small area towns, all with populations under 500, do not have exact case-counts publicly available due to privacy concerns. Their case rates per 10,000 people, however, show little change since Jan. 13. According to the math, Peru’s exact case would be between .7578 and 1.5 persons, or in effect, one person.

Town	Cases per 10,000 as of Jan. 13	Cases per 10,000 as of Jan. 20	Population
Peru	21-40	21-40	375
Windham	<1	<1	419
Andover	<1	<1	467
Stratton	<1	<1	200
Landgrove	<1	<1	155

To calculate the approximate number of infections per town when they are stated this way, divide the population by 10,000, then multiply the result by the case count range. For example, in Peru 375/10,000 = 0.0375. Then 0.0375 x 21 = 0.7875 and 0.0375 x 40 = 1.5. The whole number(s) between the low and high end of the range are the approximate number of cases.

A new “Covid-19 in Communities” map and town count list will be released on Friday, Jan. 29.