The coronavirus has ravaged all of New York City, closing schools, emptying streets and turning stadiums into makeshift hospitals. And data made public by city health officials on Wednesday suggests it is hitting low-income neighborhoods the hardest.

83 104 Riverdale 362 253 638 255 397 108 470 Coronavirus cases by ZIP code 332 Bronx 208 386 264 376 25 306 377 255 308 367 355 302 267 116 227 217 50 10 100 500 1,000 337 106 304 176 170 55 Harlem 174 126 252 204 290 147 162 110 Manhattan 212 59 104 189 190 27 105 Bayside 211 Astoria 134 187 121 85 378 331 104 49 144 Flushing 119 64 116 123 Long Island City Jackson Heights Midtown Queens 45 492 213 113 947 113 148 121 13 364 Chelsea 288 85 222 166 101 Corona 831 101 140 Greenpoint 161 318 181 Greenwich Village 96 106 181 319 68 156 112 418 122 Williamsburg 164 195 21 250 405 601 26 Middle Village 163 149 17 25 Jamaica 184 329 293 425 155 216 245 Bushwick 204 151 Brooklyn Heights 182 202 Fort Greene 260 16 182 Bedford-Stuyvesant Cypress Hills 117 130 162 Ozone Park 183 225 127 358 173 100 Park Slope 350 Red Hook 223 394 332 261 Brownsville 178 267 East New York 254 211 162 85 Howard Beach 343 Sunset Park 85 344 350 East Flatbush 264 416 St. George Flatbush Canarsie 97 771 106 61 Borough Park Flatlands Bay Ridge 386 175 209 631 534 Brooklyn 86 101 Bensonhurst 364 289 316 436 251 346 452 178 110 Sheepshead Bay Staten Island 348 Brighton Beach 133 New Dorp 143 278 Great Kills 25 146 336 170 Tottenville 67 Coronavirus cases by ZIP code Bronx 10 Manhattan 50 500 Queens 1,000 Brooklyn Staten Island Coronavirus cases by ZIP code Bronx 10 50 500 1,000 Manhattan Queens Brooklyn Staten Island By The New York Times · Note: The map shows total number of cases as of April 1. Source: New York City Department of Health and Mental Hygiene

During the first month of the outbreak in the city — the epicenter of America’s coronavirus crisis — many of the neighborhoods with the most confirmed virus cases were in areas with the lowest median incomes, the data shows. The biggest hot spots included communities in the South Bronx and western Queens.

The data, collected by the New York City Department of Health and Mental Hygiene, offers the first snapshot of an outbreak that infected more than 40,000 and killed more than 1,000 in the city in its first month.

[Read the latest coverage of the coronavirus outbreak in the New York area.]

The coronavirus has spread into virtually every corner of the city, and some wealthier neighborhoods have been overrun with cases, including some parts of Manhattan and Staten Island. But that may be because of the availability of testing in those areas. Nineteen of the 20 neighborhoods with the lowest percentage of positive tests have been in wealthy ZIP codes.

The patterns are even more striking when analyzing the data on people who visited the city’s 53 emergency rooms with the “flulike symptoms” that are a hallmark of the coronavirus.

Over all, nearly three times as many people with “flulike symptoms” like fever, cough or sore throat visited city emergency rooms this March when compared with the same month in previous years.

In the last four years, there were on average 9,250 flu-related visits to emergency rooms in March; this March, the number tripled to about 30,000.

Flu-Related E.R. Visits by ZIP Code Circles are sized by the number of flu-related visits by residents in each ZIP code. Average of March visits in 2016-19 March 2020 Average of March visits in 2016-19 March 2020 March 2020 Average of March visits in 2016-19 By The New York Times · Note: E.R. visits are calculated to show the rate per 1,000 people. Source: New York City Department of Health and Mental Hygiene

The increases in flu-related emergency room visits varied widely by neighborhood, with many of the surges occurring among residents of neighborhoods where the typical household income is less than the city median of about $60,000, the data shows.

In Corona, Queens, for example, the median household income is about $48,000, according to the U.S. Census Bureau. That neighborhood is near the Elmhurst Hospital Center, which Mayor Bill de Blasio has cited as the hardest-hit hospital in the city. Doctors in the overwhelmed emergency room there have described the conditions as “apocalyptic.”

By The New York Times · E.R. visits are calculated to show the rate per 1,000 people. Sources: New York City Department of Health and Mental Hygiene; 2014-18 American Community Survey

Dr. Jessica Justman, an epidemiologist at Columbia University in Manhattan, said the numbers were most likely because many immigrants and low-income residents live with large families in small apartments and cannot isolate at home.

“I think unfortunately this is showing how devastating that can be,” Dr. Justman said.

In New York, experts said, a vast majority of people visiting emergency rooms with flu-like symptoms probably have the coronavirus.

“We’ve actually stopped testing for the flu because it’s all coronavirus,” said Bruce Farber, chief of infectious disease at North Shore University Hospital, part of Northwell Health, a network of 23 hospitals throughout the state. “Almost anybody who has an influenza illness right now almost certainly has coronavirus.”

Many of the emergency rooms with the biggest increases in patients who have flulike symptoms are in Queens, the borough that has the highest number of confirmed coronavirus cases. There are about 616 confirmed cases for every 100,000 residents in Queens, and 584 confirmed cases for every 100,000 residents in the Bronx. That’s far more per 100,000 than the 376 in Manhattan and 453 in Brooklyn.

With infections across all five boroughs, New York has far more confirmed cases than any other city in the United States.

Coronavirus cases Coronavirus deaths 3,000 150,000 100,000 2,000 All U.S. cases All U.S. deaths 50,000 1,000 New York City March 1 March 31 March 1 March 31 Coronavirus cases Coronavirus deaths 3,000 150,000 100,000 2,000 All U.S. cases All U.S. deaths 50,000 1,000 New York City March 1 March 31 March 1 March 31 By The New York Times · Sources: New York City Department of Health and Mental Hygiene; New York Times database of coronavirus cases in the U.S.

The emergency room data also tracks admissions — the number of E.R. visitors who end up treated at a hospital. On that metric, the data shows that older visitors are far more likely to be admitted than younger visitors.

There is a simple reason for that difference, according to the hospital officials and experts: The coronavirus seems to take a bigger toll on older people, as well as those with compromised immune systems.

“I don’t think that infection rates are necessarily different between older and younger people,” said Dr. Isaac Weisfuse, the former deputy head for disease control at the city’s Department of Health. “Elderly have worse clinical outcomes than younger patients, and may have more pre-existing conditions.”

E.R. Admissions for Flulike Illness and Pneumonia Per 100,000 people Ages 0-17 18-44 45-64 65-74 75+ 30 15 Jan. Jan. Jan. Jan. Jan. March March March March March Ages 75+ 30 15 Jan. March 65-74 30 15 Jan. March 45-64 30 15 Jan. March 18-44 30 15 Jan. March 0-17 30 15 Jan. March By The New York Times · Note: The chart shows E.R. admissions as of March 31. Source: New York City Department of Health and Mental Hygiene

Over all, more than 8,500 people have been hospitalized with the coronavirus in New York City. That number is expected to soar in the coming weeks.

But officials are hopeful that the social distancing restrictions put in place by the state may have finally started to at least slow the spread of the coronavirus. They have noted that the number of hospitalizations is now doubling every six days, instead of every two or three days.

The city’s data shows a slight decline in emergency room admissions over last weekend, and then continuing increases this week.

Dr. Denis Nash, an epidemiologist at the City University of New York’s School of Public Health, said it was still too soon to tell whether the social distancing restrictions were working.

“It may be too soon to say what’s really going on here,” he said. “I just hope it means something good.”