Update: On Monday, Mayor Jim Kenney ordered a sweeping shutdown of businesses and government services in Philadelphia. All non-essential businesses will be ordered to shut down by 5 p.m. Monday, while non-essential city services will shut down this week.

As the coronavirus has taken root in Southeastern Pennsylvania, many officials have encouraged people to avoid each other and warned them not to underestimate the threat.

“Stay calm, stay home, and stay safe," Gov. Tom Wolf said Saturday. "If you can avoid visiting public places, please do so.”

Montgomery County Commissioner Valerie Arkoosh, a physician whose county has had more cases than any other in the state, has implored people to "cancel nonessential public and private gatherings, both indoor and outdoor.”

But Philadelphia Mayor Jim Kenney has taken a different approach.

“I would recommend you wash your hands, you stay out from within three feet of people, and go out and have dinner — and tip your waitstaff because they’re struggling right now,” Kenney said at a news conference Saturday. “We have to figure out a way that we can continue moving forward without panicking to the point that everything shuts down. We may be healthier but the economy will be in the tank, and we can’t have that."

Kenney later clarified that comment, emphasizing the importance of social distancing while in public spaces. But many Philadelphia bars and restaurants were crowded Saturday night, a potentially critical moment in the local spread of the virus.

Throughout the crisis, which had hit 65 confirmed cases in Pennsylvania and eight in Philadelphia as of Sunday, Kenney has stood out for his reluctance to adopt aggressive measures to slow the virus, or “flatten the curve" of growth in new infections. Such policies are designed to keep hospitals from being overwhelmed by waves of sick patients, which strains resources and drives up mortality rates.

Kenney is concerned that more stringent containment measures, such as widespread shutdowns of businesses or government services, will disproportionately harm poor residents in Philadelphia, which has the highest poverty rate of any large U.S. city. Students who rely on school-provided breakfasts or lunches, for instance, could go without meals. Blue-collar workers and hospitality-industry employees who live paycheck-to-paycheck and can’t work from home may face financial ruin in an extended lockdown.

“As we’re trying to manage this health-care crisis, we are also trying to manage through deep poverty, and making sure we have appropriate services for our most vulnerable populations,” city Managing Director Brian Abernathy, a Kenney appointee, said at a news conference Sunday.

Last week, Kenney’s administration initially discouraged gatherings of 5,000 people or more, which a University of Pennsylvania epidemiologist said was too lenient a threshold, and the mayor had planned to allow the St. Patrick’s Day Parade to take place. Following criticism of that decision, the city worked with organizers to call off the parade. The administration has since banned gatherings of 1,000 or more, while discouraging events over 250.

Kenney opposed Wolf’s decision to shut down schools across the state and initially wanted to keep open locations of the Free Library, which is now closed to the public. Philadelphia has since opened up city-owned facilities where out-of-school students can congregate. Although the capitol buildings in Washington and Harrisburg have closed to the public, City Hall remains open.

All the while, Kenney has stressed the importance of supporting the local economy and urged residents not to overreact.

Compare that with Arkoosh, who has supported more aggressive measures to stem the spread of the virus.

“Everyone is aware this is a pandemic. This is no time to be cute,” Arkoosh told The Inquirer last week. “And I can almost guarantee you that if these mitigating measures work, people are going to look back and say, ‘What did they do all that for?’”

Kenney spokesperson Deana Gamble said it’s “very important to note that Philadelphia is very different than Montgomery County.”

“The decisions Mayor Kenney has to make are vastly different from the decisions that Commissioner Arkoosh has to make,” she said. “We are continually trying to balance prudent health protections, while avoiding reactions that are simply not warranted by the situation."

All four of Philadelphia’s suburban counties are now subject to a request by Wolf to shut down all nonessential businesses. The number of officially confirmed cases in the city on Sunday doubled to eight. Another 45 people have pending tests, and 87 are being monitored after potential exposures. (There are likely many other cases: Statistical reviews of countries hit in the first wave of the pandemic have shown that the number of cases governments could identify when the infection began spreading in an area was a fraction of the actual total at that time.)

Although there have so far been fewer reported cases in Philadelphia than its suburbs, the public health risk posed by the coronavirus is potentially more grave in the city, where social distancing is more difficult and a greater percentage of residents lacks health-care coverage.

Kenney has encouraged such basic precautions as hand washing, and, like other officials, he has also encouraged Philadelphians who feel sick to avoid public spaces. Research on the virus as it unfolds, however, has suggested that experts may have initially underestimated the extent to which the virus can spread from people who have not yet begun to show symptoms — and would not know to stay home.

At Sunday’s news conference announcing the four new cases in Philly, which Kenney did not attend, city Public Health Commissioner Thomas Farley noted that asymptomatic carriers of the disease have already played a role in its spread in Philadelphia.

“It does happen, and it appears that it has happened here,” Farley said.

Because of that research, Anthony Fauci, the director of the National Institute of Allergy and Infectious Disease, said he would not rule out supporting a national ban on restaurants and bars.

“I would like to see a dramatic diminution in the personal interaction that we’re seeing in restaurants and in bars,” Fauci said Sunday on CNN. “Whatever it takes to do that, that’s what I’d like to see.”

Staff writers Laura McCrystal, Allison Steele, and Aubrey Whelan contributed to this article.