Maryland COVID-19 Cumulative County Case Counts

MD COVID-19 - Cases by County provides the cumulative number of positive COVID-19 cases among Maryland residents, reported by local health departments via the ESSENCE system. The dataset includes daily case counts for Maryland's 23 counties and Baltimore City, plus an 'Unknown' jurisdiction column. It was published by opendata.maryland.gov but is deprecated as of October 10, 2025, with updates having shifted from daily to weekly in April 2023.

Use Cases

• Analyze temporal case trends by comparing the DATE field with county-specific columns like Montgomery or Baltimore_City.
• Assess geographic spread by ranking counties such as Prince_Georges, Anne_Arundel, and Howard based on their cumulative case values.
• Identify reporting anomalies or unassigned cases by monitoring the 'Unknown' jurisdiction column over time.
• Model county-level case correlations by joining time-series data from columns like Frederick, Washington, and Wicomico.

Strengths

• Contains data for 24 distinct geographic entities (23 counties plus Baltimore City).
• Includes a dedicated DATE column for temporal analysis of case progression.

Limitations

• Dataset is deprecated and no longer updated, limiting analysis to historical trends only.
• Sample size and total row count are unknown, preventing assessment of data volume.
• The presence of an 'Unknown' column indicates some cases lack geographic specificity.

Provenance

Source

opendata.maryland.gov, likely the Maryland Department of Health.

Collection Method

Positive COVID-19 test results reported daily by local health departments via the ESSENCE system.

Time Range

null

Freshness

Deprecated as of 2025-10-10; final update was 2025-10 14.

Geography

State of Maryland, United States, at the county and Baltimore City level.