Dropping infection numbers may boost case for going green

For counties seeking to move to green soon in southwestern Pennsylvania, the data seems to be on their side.

Since April, the Post-Gazette has been tracking the state’s daily data releases — COVID19 new cases, negative tests and death figures for every county. Now that the southwest region has been in the yellow zone for two weeks and parts of the state move to green for the first time Friday, it is possible to look at the data over time to see whether reopening or partial reopening has had an impact on new cases anywhere in the state — and to see where parts of the state stand relative to the health department’s guidelines for reopening.

To do this, the Post-Gazette has calculated a rolling 14-day count of new cases per 100,000 population for each county and region. Sustained changes in the numbers of new cases are visible, but the long-term tally also serves to smooth out dayto-day fluctuations in the data. (For instance, weekends tend to see lower reporting, followed by a surge midweek as the

backlog is cleared.)

This 14-day count is the same metric the health department initially used to determine which counties should be moved from red to yellow. Counties coming in under 50 new cases per 100,000 in the preceding 14 days were deemed potentially ready. It was never the only metric considered — state Health Secretary Dr. Rachel Levine repeatedly emphasized hospital capacity, population density, testing and contact tracing capacity and modeling from Carnegie Mellon University were also taken into account.

In recent weeks, Gov. Tom Wolf and Dr. Levine have indicated the metric has declined in importance because the statewide expansion of testing capacity may unfairly push some counties above the 50-case target. Nonetheless, every county in the southwest remains comfortably below the target, a potentially promising sign for the region’s ability to control the virus and to move into green status.

In short, the statewide data shows every region of the state has seen a decline in the number of new cases — with the exception of the northwest, which has seen climbing new cases since moving to yellow.

Southwest region

With the notable exception of Beaver County, the southwest region has kept the number of new cases quite low throughout April and May. Every county in the region has seen a decline in the 14-day count of new cases, even after most moved to yellow on May 15 (with the exception of Butler County, which has increased marginally). Westmoreland County has gone from the second-highest tally in the region on May 1 (41) to the third-lowest on May 28 (6), and Greene County (population 36,506) has not seen a new case since May 2.

Allegheny County, the largest in the region by population, has seen a modest decline in its new case count, going from roughly 31 to 25, and it has largely plateaued at that level — an accomplishment, given that it contains the second-largest city in the state and the highest population density outside the southeast. Dr. Levine has praised Allegheny County’s performance as “fantastic” and says she speaks frequently with county Health Director Dr. Debra Bogen.

Beaver County is an outlier in the region. Its high case count largely reflects the serious outbreak at the Brighton Rehabilitation and Wellness Center, a 400plus bed nursing home that saw rapid, uncontrolled spread of COVID-19 among residents. Over 400 of the county’s 579 cases are directly connected to the facility — either staff or residents there. It has still seen a decline in new cases in recent weeks, however.

Northwest region

The rural northwest region is the only one to see an increase in the 14-day count of new cases per 100,000 population. On May 1, the region had a tally of just eight new cases per 100,000, the lowest region by far. It began to see an increase a week after moving to yellow, and between May 15 and May 28, its 14day count steadily rose from 11 new cases per 100,000 to 17.

The regional increase is not universal, however; it is largely driven by increases in new daily cases in the most populous counties in the region, Erie (272,061 inhabitants) and Mercer (110,683). While the other counties in the region have declined to or plateaued at single-digit new case figures — Forest and Jefferson have not seen new cases in weeks — Mercer has gone from 8 on May 1 to 22 on May 28. Erie has gone from 14 new cases per 100,000 on May 1 to 42 on May 28, and while Mercer’s count appears to have peaked last week, Erie’s is still on the rise.

Some Mercer County officials have asked the governor to move Mercer to green along with the rest of the northwest region, arguing that many of the new cases there can be traced to a single “contained” outbreak in Farrell.

Statewide picture

Over the past month, new cases in Pennsylvania have been on a nearly constant decline. The 14day tally, which stood at 136.73 new cases per 100,000 population on May 1, has dropped by roughly two cases per day since then. The raw number of new cases, which peaked in April near 2,000 per day, has dropped considerably and has not exceeded 1,000 since May 10.

The drop in new reported cases comes despite a rise in the amount of daily tests reported. Since May 1, the number of total positive and negative tests reported has nearly doubled from 227,448 to 427,846, and the average number of new positives and negatives reported per day increased from 5,691 in the last two weeks in April to 6,564 from May 1 to May 15 and 8,308 from May 16 to May 28.

The number of tests conducted per day is likely even higher — a spokesperson for the Department of Health said if someone is tested multiple times, they are only counted once in the state’s counts of positive and negative tests. On May 21, for example, the count of positive and negative tests reported increased by about 11,000, but Dr. Levine said over 13,000 people in total received test results that day.

The curve of new COVID-19 deaths tends to follow the new case curve by several weeks, so it hasn’t seen the same level of decline. The daily average was roughly 118 newly reported deaths in the last two weeks of April. That increased to 137 per day on average from May 1 through May 15, when many of the initial reconciliations took place, but has since fallen to 79 per day on average from May 16 to May 28.