With 203 cases, Lewiston has had the most COVID-19 cases of any ZIP code in the state, while the most densely populated part of Portland has the state’s highest per capita rate of infections, according to data from the Maine Center for Disease Control and Prevention.

The case counts – which are a cumulative tally for the pandemic, not active cases or current infection trends – show the disease has generally hit hardest in Maine’s urban centers and their suburbs. But there are surprising clusters in parts of the state where it might not have been as expected.

The northern Penobscot County town of Medway has the second highest infection rate for any of the 55 zip codes for which the Maine CDC released full case counts: 12 confirmed cases, or 1 for every 121 people in town. The affluent Portland suburbs of Cape Elizabeth and Falmouth were third and fourth, with 1 case per 123 and 124 residents respectively.

Westbrook, Portland’s Deering-Riverton and West End-Rosemont-Stroudwater areas (04102 and 04103), Kittery Point, Lewiston, Cape Neddick and Scarborough rounded out the top 10 ZIP codes per capita.

Portland’s 04101 ZIP code, which includes downtown, the East End and Bayside, had had the highest prevalence, with 170 cases among 18,739 residents, or 1 for every 110 people.

The data, which the Maine CDC released Wednesday night, is current through Tuesday. It was not immediately clear how often the state plans to update the data.

To protect patient privacy, the Maine CDC released an exact case count for only 55 of Maine’s 400 ZIP codes, those where there were at least six cases and where at least 50 people live in the ZIP code. Also excluded were all ZIP codes in two counties with low disease prevalence – Piscataquis and Washington – again in an attempt to ensure patent privacy, according the agency’s website.

Until now, the agency had  reported cases only by county. All other New England states have been reporting COVID-19 case counts by municipality since April 27. The Press Herald last month filed a public records request asking the Maine CDC for infection data by town.

Most Maine municipalities have just one ZIP code, including cities like Lewiston and Biddeford, but Portland has three. When combined, they show the city as a whole as having by far the most total cases to date, 456, but a per capita rate of only 1 per 152 residents, which would make it the fifth most impacted municipality in the state, after Medway, Cape Elizabeth, Falmouth and Westbrook. The latter three towns have been the sites of tragic nursing home outbreaks.

According to news reports, two of Medway’s 12 confirmed cases were Medway Post Office employees who have since recovered. Maine CDC spokesman Robert Long said via email Thursday that there had been no outbreaks – three or more confirmed cases – associated with congregate living or work sites in Medway, but that he could not provide further information on cases there for reasons of patient privacy.

Asked at Thursday’s news briefing about what the ZIP code data tell him about the pandemic, Maine CDC Director Dr. Nirav Shah said it matches his expectations of what it would show. “Highly dense populated areas have more cases of COVID-19,” he said. “That’s based on the biology of how the disease is transmitted and is what we would have predicted.” He also noted that places with “a high number of congregate settings” had the highest concentrations of cases.

Shah urged people living in towns that haven’t yet reported a case to continue to act as though the disease were present, because people travel from place to place, potentially spreading the disease with them.

Consistent with previously released county-level case counts, the vast majority of cases and the places with the highest prevalence have been in ZIP codes within York, Cumberland and Androscoggin counties, though the agency’s data shows there have been confirmed cases in most of the ZIP codes in the 14 counties for which it provided data.

Among the 55 ZIP codes where exact case counts were disclosed were several municipalities outside southern Maine. Belfast – site of a now-contained outbreak at the Tall Pines nursing home that infected 32 residents, killing 14 of them – has had 35 cases overall, or 1 in 265 residents. Phillips, in north Franklin County, has had six cases, or 1 in 292 residents, while neighboring Farmington has had 15, or 1 in 615.

Most cities outside southern Maine had low per capita rates. Bangor has had 42 cases (or 1 in 1,071), Augusta 67 (1 in 379) and Waterville 17 (1 in 1,537). By contrast, Lewiston has had 1 case per 182 residents; Auburn, with 81 cases, 1 in 290; Scarborough 85 cases or 1 in 239; and South Portland 105 cases or 1 in 250.

Topsham and Bath (in Sagadahoc County), Skowhegan (in Somerset), Oakland and Brewer (in Penobscot), Gardiner (in Kennebec) and Camden (in Knox) also had at least six cases, so made the disclosure list.

Also notable were areas that have had no confirmed cases at all to date, according to the CDC data, including Harpswell, Phippsburg and Georgetown; Bar Harbor; the towns of the Hancock County peninsula that includes Castine and Blue Hill; and several towns in the Parsonsfield area along the New Hampshire border in southernmost Maine. Among island communities, North Haven, Islesboro, Swans Island and Frenchboro have been spared, but Vinalhaven, Isle au Haut, Chebeague and Peaks each have between one and five cases.