Covid-mask

Positivity rate eclipses state average as testing lags

Roseville, CA- A key measurement health and public officials cite to measure the prevalence of community spread of COVID-19 is the positivity rate. During the March through May period, Placer County was tracking a positivity rate of 1.85% which indicated low community spread. A total of 217 positive cases were recorded throughout all of Placer County during that time period.

Naturally as additional testing occurs more positive cases will be identified. However, the rate of positivity has risen near 700% over the past two months, indicating an increasing and higher rate of community spread. Testing in Placer, ranks in the bottom third of the state and has been drifting even lower.

As of August 3, 2020, Placer County is reporting a 7-day positivity rate of 13.8% giving it the dubious distinction among the 10 highest rates in California. Statewide, the positivity rate statewide is 7.5%. Total cases to date in Placer County are 1,938 with 17 deaths and 64 currently hospitalized with Covid.

Likely Underestimates

Aug 3, 2020 – Placer County dashboard “Please note that CalREDIE, the statewide electronic disease reporting system, is experiencing serious unresolved processing delays. As such, new cases presented here are likely an underestimate of true incident cases being reported. This impacts many of our statistics, including case rates and percent increase estimates.”

Where Placer County currently ranks

California Covid-19 Testing Rate (per 100,000 residents)

Lassen410.1
San Francisco348.8
Los Angeles339.9
Marin324.6
Kings321.6
Imperial282.4
Kern267.9
Mono266.1
Napa265.5
Santa Clara257.4
Ventura254.3
Madera250.5
Mendocino237.3
Santa Barbara233.5
San Joaquin224.3
Stanislaus216.5
Solano212.9
Fresno212.3
Tulare206
San Luis Obispo204.7
San Mateo202
San Bernardino197.1
San Benito195.2
Tuolumne194.6
Siskiyou192.7
Alameda190
Contra Costa180.8
Shasta176.5
Monterey175.2
Amador171.7
Sonoma*167.1
Orange158.5
Mariposa158.2
Yolo155.4
Sacramento154.5
Riverside149.6
Merced149.5
Santa Cruz146.9
Calaveras141
San Diego137
Lake133
Placer132.9
Nevada129.1
Plumas124.8
El Dorado120
Sierra119.2
Colusa116.3
Yuba109.2
Sutter107.9
Humboldt102.2
Tehama101.5
Del Norte90.7
Butte88.2
Glenn77.4
Trinity71.7
Inyo50.3
Alpine38.4
Modoc22.6

Highest Positivity Rates in California

Tulare19.6
Merced19.3
Kern19.2
Stanislaus18.1
San Joaquin17.5
San Bernardino17.1
Madera16.4
Riverside14.7
Monterey14.6
↑ Placer13.8
Kings13.5
San Benito13.1
Colusa13
Fresno13
Sutter12.3
Yuba12.1
Glenn11.9
Orange11.7
Imperial11.5
Mono11.2
Santa Barbara10.3
Sacramento9.6
Los Angeles8.2
Ventura8.1

Source: California Department of Public Health and Placer County Covid-19 dashboard

John Hopkins University on Positivity Rates

“The rate of positivity is an important indicator because it can provide insights into whether a community is conducting enough testing to find cases. If a community’s positivity is high, it suggests that that community may largely be testing the sickest patients and possibly missing milder or asymptomatic cases.”