Mayor London Breed and public health officials said Monday the city plans to spend $5 million to cut potential exposure to the new coronavirus for some of the city’s most vulnerable residents.

The initiatives are targeting the more than 25,000 people living in city homeless shelters, including Navigation Centers, and in single-room occupancy hotels. Health officials have identified such “congregate living” settings, where people are clustered in close quarters, as particularly high-risk for spreading the virus.

Homeless shelters will also be kept open around the clock, provided that the organizations that run them have enough staff to operate on a 24-7 basis, city officials said.

Individuals 60 years old and older, particularly those with underlying respiratory health conditions, are at the highest risk of getting seriously ill and dying once they’ve contracted the disease. Recently released research suggests that, across the country, 44% of people who fall into homelessness do so after age 50.

San Francisco Health Director Dr. Grant Colfax has said repeatedly that anyone over age 60 with underlying health conditions should “stay home as much as possible.”

The bulk of the funds will be used to hire dozens of janitors who will act as a roving cleaning crew, scrubbing shelters, permanent supportive housing buildings and city-funded SROs on a daily basis. The city has also laid out requirements to protect the health of the cleaning crews, requiring training and equipment needed for workers to protect themselves.

The city will also mandate rigorous cleanliness standards at privately owned SROs through a public health order. City health officials plan to inspect those buildings and enforce the standards beginning this week. The city has earmarked $1 million of the $5 million emergency fund to help private SRO owners comply with the new standards, which will go toward cleaning supplies and other necessities.

The additional cleaning efforts will focus on disinfecting high-touch surfaces and dispensing hand-cleaning supplies, including hand sanitizer. Warnings will also be posted in multiple languages in SROs and shelters.

“We have to do more to keep these places clean and work to keep people healthy as this disease spreads within our community. This emergency fund and this public health order are part of our work to respond aggressively to the challenges presented by COVID-19 each and every day,” Breed said in a statement.

The funding will allow the city to maintain the new standards and services for the next few months, officials said. After that, they could be renewed with additional funding. Breed’s decision to declare a state of emergency for San Francisco over concerns about the spread of coronavirus makes it easier for city officials to tap resources needed to protect public health.

The public health order builds upon the city’s efforts last week to discourage people from organizing and attending events that draw large crowds. All city-organized events have been canceled for the next two weeks, including the St. Patrick’s Day parade and performances at the War Memorial and Performing Arts Center venues, including the Louise M. Davies Symphony Hall.

The city will also be increasing meal services at shelters and SROs to further encourage people to stay indoors. Shelter meal services and meal deliveries to SROs — both city-funded and privately owned — will be expanded throughout the day.

Supervisor Aaron Peskin, whose district includes Chinatown and other densely populated neighborhoods, said the city’s northeast quarter “has the highest concentration of people who are vulnerable to this epidemic. Time is of the essence and we’re starting to make real moves on the ground that will hopefully save lives.”

Dominic Fracassa is a San Francisco Chronicle staff writer. Email: dfracassa@sfchronicle.com Twitter: @dominicfracassa