i
Trends in number and distribution of COVID-19 hotspot counties — United States, March 8–July 15, 2020
-
August 14, 2020
-
-
Source: MMWR. Morbidity and Mortality Weekly Report ; v. 69, early release, August 14, 2020
[PDF-836.77 KB]
Details:
-
Personal Author:
-
Corporate Authors:
-
Description:What is already known about this topic?: U.S. geographic areas most affected by the COVID-19 pandemic have changed over time.
What is added by this report?: During March 8–July 15, 2020, 818 (26%) of 3,142 U.S. counties were identified as COVID-19 hotspots (counties meeting specified criteria relating to temporal increases in number of cases and incidence); these counties included 80% of the U.S. population. More hotspots were identified in the South and West during June–July.
What are the implications for public health practice?: Identification of hotspot counties allows for a focused approach for assessing localized COVID-19 outbreaks and implementing targeted public health response activities.
The geographic areas in the United States most affected by the coronaVirus disease 2019 (COVID-19) pandemic have changed over time. On May 7, 2020, CDC, with other federal agencies, began identifying counties with increasing COVID-19 incidence (hotspots) to better understand Transmission dynamics and offer targeted support to health departments in affected communities. Data for January 22–July 15, 2020, were analyzed retrospectively (January 22–May 6) and prospectively (May 7–July 15) to detect hotspot counties. No counties met hotspot criteria during January 22–March 7, 2020. During March 8–July 15, 2020, 818 counties met hotspot criteria for ≥1 day; these counties included 80% of the U.S. population. The daily number of counties meeting hotspot criteria peaked in early April, decreased and stabilized during mid-April–early June, then increased again during late June–early July. The percentage of counties in the South and West Census regions* meeting hotspot criteria increased from 10% and 13%, respectively, during March–April to 28% and 22%, respectively, during June–July. Identification of community Transmission as a contributing factor increased over time, whereas identification of outbreaks in long-term care facilities, food processing facilities, correctional facilities, or other workplaces as contributing factors decreased. Identification of hotspot counties and understanding how they change over time can help prioritize and target implementation of U.S. public health response activities.
Aggregate, cumulative counts of reported COVID-19 cases (1) were collected by USAFacts through automated extraction or manual entry of information from state and local health department websites.† CDC and the Applied Physics Laboratory (APL) of Johns Hopkins University cleaned the data to ensure nonnegative daily case counts and correct reporting errors (such as instances of 2 days’ of data being recorded on a single day) and analyzed data by county and report date. Hotspot counties were identified among counties in U.S. states and the District of Columbia by applying standardized criteria developed through a collaborative process involving multiple federal agencies; hotspots were defined based on relative temporal increases in number of cases.§ Prospective hotspot detection began on May 7, 2020. The same Methods were applied retrospectively to detect hotspot counties using data from January 22, when the first U.S. COVID-19 case was reported (2), until May 6, 2020; no counties met hotspot criteria during January 22–March 7, 2020. Data from prospective and retrospective hotspot detection were analyzed to characterize Trends in COVID-19 hotspot counties and hotspot alerts (each time a county meets hotspot criteria for 1 day) over time. Counties meeting hotspot criteria were analyzed by U.S. Census region (3) and urbanicity¶ (4).
Suggested citation for this article: Oster AM, Kang GJ, Cha AE, et al. Trends in Number and Distribution of COVID-19 Hotspot Counties — United States, March 8–July 15, 2020. MMWR Morb Mortal Wkly Rep. ePub: 14 August 2020.
mm6933e2.htm?s_cid=mm6933e2_w
mm6933e2-H.pdf
-
Subjects:
-
Source:
-
Document Type:
-
Place as Subject:
-
Volume:68
-
Issue:34
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
