Health & Fitness
'High' COVID Spread In 13 Maryland Counties: CDC
The CDC recommends mask use in jurisdictions with "high" or "substantial" transmission of the virus. All 24 Maryland jurisdictions qualify.

MARYLAND — Officials say 13 counties in Maryland now have a high rate of transmission and 11 have substantial rates of transmission of the coronavirus.
Fully vaccinated people as well as those who have not been vaccinated against COVID-19 should wear masks indoors in public if they live in an area with "substantial" or "high" transmission of the virus, the Centers for Disease Control and Prevention (CDC) recommends.
Those who aren't fully vaccinated are urged to wear masks in public no matter what the level of transmission is, according to the CDC.
Find out what's happening in Baltimorefor free with the latest updates from Patch.
Baltimore City as well as Montgomery and Prince George's counties have mandated masks indoors regardless of vaccination status. Of those, Prince George's County is the only one where spread has been deemed "high," while the others have "substantial" transmission of the virus.
Transmission levels are determined either by new cases per 100,000 residents in the last seven days or the percentage of coronavirus tests that come back positive; the higher category determines the transmission level.
Find out what's happening in Baltimorefor free with the latest updates from Patch.
Thresholds
New cases per 100,000 in past seven days
- Low: 0-9.99
- Moderate: 10-49.99
- Substantial: 50-99.99
- High: >100
Positive test rate
- Low: <5
- Moderate: 5-7.99
- Substantial: 8-9.99
- High: >10
The latest CDC statistics cover the Aug. 7 to Aug. 13 period for case rates and Aug. 4 to Aug. 11 for positivity rate in Maryland.
These Maryland counties have "high" spread, according to the CDC:
- Allegany County
- Caroline County
- Cecil County
- Charles County
- Dorchester County
- Frederick County
- Kent County
- Prince George's County
- Somerset County
- St. Mary's County
- Washington County
- Wicomico County
- Worcester County
These Maryland jurisdictions have "substantial" spread, according to the CDC:
- Anne Arundel County
- Baltimore City
- Baltimore County
- Calvert County
- Carroll County
- Garrett County
- Harford County
- Howard County
- Montgomery County
- Queen Anne's County
- Talbot County
Maryland is one of six states with "substantial" transmission. Maine, Michigan, New Hampshire, Pennsylvania and Vermont. All others have been deemed "high" transmission.
The Northern Mariana Islands, Palau and Republic of the Marshall Islands have low transmission rates, according to the CDC.


The delta variant of the coronavirus continues to drive case rates higher in the U.S., especially in places with low vaccination rates.
Anyone in an area with substantial or high levels should wear masks indoors, based on guidelines issued by the Centers for Disease Control and Prevention (CDC).
See Also:
- Baltimore Orders Masks Indoors As Coronavirus Infections Surge
- Mask Mandate Returns Indoors In MOCO: Council Votes Yes
- Masks Required Again In Prince George's; Delta Variant Spreads
The CDC also recommends indoor public mask use for people with compromised immune systems or other high-risk factors, regardless of vaccination status. People who live with someone at higher risk for coronavirus complications should also consider using masks.
See Also:
- Masks Required In Anne Arundel County-Owned Buildings
- AACPS Requires Masks For All Regardless Of Vaccination Status
- State of Emergency In Maryland Set To Expire
- Masks Required In Baltimore County Government Buildings
- Masks Required In Baltimore County Public Schools As Of Tuesday
- Harford County Public Schools Issues Guidance On Masks
- Masks Required In All Howard County Buildings: Officials
- Masks Required For All HCPSS Students, Staff, Visitors This Fall
- Masks Required In MOCO Schools, Buses; Vaccinations For Staff
- Masks Required For Prince George's Co. Public Schools This Fall
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