KEY TAKEAWAYS

    For municipality data, research brief, and technical report, scroll below this box.

    After two years of tracking COVID-19 case rates by county in New Jersey, the Walter Rand Institute COVID-19 tracker is closing. We made this decision for two reasons. First, as many researchers have noted, official daily case counts are becoming a less reliable indicator of COVID-19 impacts as more and more people take rapid at-home tests that are not reported to official sources. Second, there are now many websites that allow users to easily compare case rates between geographic areas. We will continue to review data, and if it seems that our blend of local knowledge and data analysis is useful again, we will resume COVID-19 tracking. In early June 2022, we will release another brief report highlighting county-level differences in COVID-19 impacts between March 2020 and March 2022.

Contact Sarah Allred at srallred@camden.rutgers.edu



Municipal-level Data


In New Jersey, it has been difficult to obtain official data about the number of positive COVID-19 tests in each municipality. However, many county health departments and other public sources report the number of confirmed COVID-19 cases in municipalities each day. On April 22, 2020, WRI began tracking these sources. A research brief describing and analyzing two waves of COVID-19 cases in New Jersey utilizing this data is here. The methods used to collect and analyze the data are described in a technical document here.

This dataset is the number of confirmed COVID-19 cases in municipalities throughout New Jersey on April 27, 2020; June 30, 2020; and December 13, 2020.



Current Trends


  • This map shows the rates of new COVID-19 cases in New Jersey. The colors in the map are based on the number of new COVID-19 cases per day for every 100,000 residents in the county. The data are smoothed over a week to provide a better estimate. Red indicates that counties have more than 25/100K. Orange indicates 10-25/100K. Yellow indicates 1-10/100K, and green indicates <1/100K. The color coding is from Harvard's Global Health Institute.

Regional Definitions (based on disease progression)


  • Northeast: Bergen, Essex, Hudson, Middlesex, Monmouth, Ocean, Passaic and Union counties (counties with >1000 cases on April 1).
  • Northwest: Hunterdon, Mercer, Morris, Somerset, Sussex and Warren counties.
  • South: Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester, Salem Counties.

Where we are now: New Cases Each Day Per 100,000 Population

WHAT IT MEANS

  • To better show new trends, plots of new COVID-19 cases now show data only from 2021. Recently, cases are increasing across the state and in all three regions of the state.


Where we are now: New Deaths Each Day Per 100,000 Population

WHAT IT MEANS

  • To better show current trends, plots of new COVID-19 deaths now show only 2021 data. Deaths are increasing again in the state and in the country. Because the numbers overall are small for deaths in New Jersey, they are particularly susceptible to noise.


County-Level Plots: new cases each day per 100,000 population


County-Level Plots: new deaths each day per 100,000 population


Technical Notes:
  1. Data are downloaded from JHU Github approximately 7 a.m. each day. JHU Github sometimes lags New Jersey Department of Health Dashboard.
  2. Day 10 (March 31, 2020) of the JHU Github appeared to contain incorrect data for deaths. We averaged days 9 and 11 to get day 10. Day 31 also contained incorrect data, so we performed a similar averaging procedure. On day 36, Hudson County reported a lower number of total deaths than on day 35. To avoid “negative deaths”, we adjusted the death estimates for the previous days.
  3. Population estimates are from the 2010 Census.

Methods:

The plots here visualize the progress of COVID-19 across three regions in New Jersey. New cases (first figure) and new deaths (second figure) are shown on the y-axis, and time (in days) is shown on the x-axis. To account for population differences between the three regions, we plot the number of new cases (or deaths) per 100,000 population. For example, if the value on the y-axis is 10, that would mean that 10 out of every 100,000 people tested positive for COVID-19 the previous day. The first day on the graph is March 22, 2020.

We plot a rolling 7-day average of the data. This means that each days number is an average of 7 days. We do this because there are variations in the time it takes to report deaths. For example, a health department might be overwhelmed and unable to enter all the deaths on one day, making the numbers look lower than they should.

In addition to plotting data by county, we also average across three regions of the state. The first is northeastern counties. These are counties that had more than 1000 infections each on 4/1/2020, and include Bergen, Essex, Hudson, Middlesex, Monmouth, Ocean, Passaic and Union counties. The second is northwestern counties. These all had fewer than 1000 infections on 4/1/2020. The third is southern counties, including Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester, and Salem counties. These counties had fewer than 250 cases on 4/1/2020.