ZIP code-level data on Maryland coronavirus cases shows hot spots, transmission in many Baltimore neighborhoods

Some of Maryland’s highest concentrations of confirmed coronavirus infections are occurring around Baltimore’s Park Heights neighborhood and into Baltimore County’s northwest corridor, and the virus is “clearly spreading” in many other neighborhoods throughout the city, according to the first ZIP code-level data on COVID-19 cases in the state.

Data released Sunday shows more cases in the city’s 21215 ZIP code — 137 — than any other in the state, and concentrations of dozens of cases in the Pikesville and Randallstown areas. But the virus is not limited to those hot spots, with clusters of infections also reported along the Belair Road corridor in Northeast Baltimore and down the city’s east side.


“It’s clearly spreading,” said Joshua Sharfstein, a former city health commissioner. “This is a beeping warning light that there is community transmission right now in Baltimore.”

Elsewhere around the state, the Silver Spring area, the Prince George’s County suburbs of Washington and the Frederick area are also hot spots for spread of the infection known as COVID-19.


The data is helping to inform efforts to protect vulnerable residents, feed families in need and control the spread of the virus that as of Sunday has infected more than 8,200 Marylanders, and killed 235. The state released the ZIP code driven information amid calls that it ensure that resources to combat the pandemic are applied equitably, given that a racial breakdown of cases released last week showed a disproportionate toll on black residents.

State Del. Nick Mosby, whose legislative district includes parts of west and northwest Baltimore and had been calling on Gov. Larry Hogan to release the ZIP code data, said the numbers underscore that all residents need equal access to coronavirus testing, protective equipment and other measures that slow the virus’ spread.

“No matter how rich, how poor, no matter what part of the state, no matter what your line of work is, it’s a virus and it spreads,” Mosby said. “That’s why it’s so important to ensure we’re equitable in effectively flattening the curve.”

Hogan said the data is helping to inform where investment and precautions are most needed. In Northwest Baltimore, that included the launch of a testing center at Pimlico Race Course last week.

In Park Heights, George Mitchell said he has recently noticed more people wearing masks and maintaining 6 feet of distance from others when he serves them at the Langston Hughes Community, Business & Resource Center on Tuesdays and Fridays. About 500 people, twice as many usual, visited the food pantry there on Tuesday, he said.

Mitchell was glad to see people taking better precautions. Though he said he doesn’t personally know of any COVID-19 cases in the community, he said he is nonetheless urging people to take the coronavirus seriously.

“I’m telling people, ‘This thing is real,’” Mitchell said. “We’ve got to isolate and make sure exactly where it’s coming from.”

The neighborhood was quiet on Easter Sunday. The dark green COVID-19 testing tents at Pimlico Racecourse were desolate.


Those walking in the largely empty streets were mostly alone. Small groups appeared to be keeping their distance. People sitting outside their homes, chatting with neighbors from porch to porch, mainly wore masks.

A barbecue stand at the corner of Reisterstown Road and Hayward Avenue had a steady stream of customers. A group of about 15 people launched a motorcycle ride nearby, apparently taking advantage of the overcast, warm weather.

Mosby stressed that Park Heights and many other neighborhoods simply aren’t equipped to defend against the virus. Many residents rely on public transportation, making social distancing difficult if not impossible, and work in low-wage and low-skill jobs once overlooked, but now essential.

“Everyone’s relying on them,” the Democratic lawmaker said Sunday on ABC’s This Week. “What are we doing to protect them?”

Neighborhoods that were already considered “food deserts” for lack of affordable and healthy groceries are now faced with choices between exposing themselves to the virus or going hungry, said Kea Crowder, co-founder of the Movement Team. The community group has been distributing meal kits and care packages in neighborhoods all across the city through a COVID-19 grant from the Baltimore Community Foundation.

“A lot of folks don’t want to venture out,” she said. “Others don’t have means to get anything.”


While the ZIP code data shows where some coronavirus hot spots are, it is not a perfect measure of the virus’ prevalence, noted Sharfstein, the vice dean for public health practice and community engagement at the Johns Hopkins Bloomberg School of Public Health. He said it can sometimes simply reflect greater access to testing.

Also, ZIP codes are not uniform in size or population, making comparisons difficult.

Though the 21215 ZIP code has the state’s highest number of coronavirus cases, the rate of infection there, about 2.3 cases per 1,000 residents, is lower than in other postal codes. Factoring in population data, the virus appears to be even more prevalent in Randallstown, where the confirmed infection rate is approaching 3 per 1,000 residents, and Pikesville, at 2.4 cases per 1,000 residents.

Even more of an outlier: An infection rate of 3.5 people per 1,000 in the Mount Airy ZIP code that includes Pleasant View Nursing Home, where at least 81 residents and 31 staff members have tested positive for the coronavirus.

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High numbers of confirmed infections are appearing most frequently in Prince George’s and Montgomery counties.

Across nine Prince George’s County ZIP codes, there are nearly 1,000 confirmed cases, accounting for about 12% of the statewide total. And the Maryland ZIP codes with the second-, third- and fourth-most confirmed COVID-19 infections are all in the Silver Spring area of Montgomery County, totaling more than 380 cases.


More useful than confirmed case counts by ZIP code, granular data on the demographics of people being hospitalized or who die from COVID-19 could more accurately reveal where the virus is spreading most rapidly, Sharfstein said.

Maryland health officials release breakdowns of confirmed cases and deaths county by county, and by age, gender and race, but only statewide totals of the numbers of people who are hospitalized or who have recovered from infection and been released from isolation.

Sharfstein said the data should not suggest any reason to ease alarm in Baltimore ZIP codes where fewer COVID-19 cases have been confirmed.

“There’s no breathing a sigh of relief in data that shows the virus is spreading across the city,” he said. “It shows that it’s very important that access to testing and care be available across the city.”

Baltimore Sun reporter McKenna Oxenden contributed to this article.