The rapid increase of coronavirus cases in the Washington region has made the painstaking task of contact tracing more difficult, moving public health officials to prioritize whom to inform about potential exposure in a triage-like effort to keep the highly transmissible omicron variant from spreading even faster and further.

Since Thanksgiving, the seven-day average of new cases in the District, Maryland and Virginia has increased elevenfold, landing at 30,929 on Friday, a spike that has begun to overwhelm local hospitals and urgent-care centers.

But with the number of potential contacts infected by the highly contagious omicron variant far higher than with previous variants, it is not feasible for health officials to reach everyone who may be at risk — particularly after some localities reduced their contact tracing ranks during a lull in the pandemic over the summer, public health experts say.

“I don’t think we can scale up enough to make a huge difference in terms of limiting transmission with contact tracing,” said Crystal Watson, a senior scholar at the Johns Hopkins Center for Health Security who has focused on contact tracing efforts during the pandemic.

“It’s moving so quickly, by the time someone gets a test — and we’re having lots of delays with testing — that person probably has gone on to infect others who may have gone on to infect others,” she said.

With even fully vaccinated residents being infected and, in some cases, getting sick enough to be hospitalized, public health experts say it’s even more vital for area residents to get tested five days after a potential exposure and to follow federal guidelines to prevent additional infections if they learn they’ve come into close contact with someone who has tested positive.

For the unvaccinated, those guidelines mean a quarantine of at least five days and then wearing a mask around others for another five days. Those who have been fully vaccinated are encouraged to wear a mask around others for five days and, if they develop symptoms, to stay home and isolate.

Some localities in the Washington region have started to hire more contact tracers and case investigators; the latter serve as a first point of government contact for someone who has tested positive to share information about others who were potentially exposed so they can be connected with a contact tracer.

Maryland plans to hire another 100 contact tracers in the coming weeks, adding to its statewide ranks of 700 in local health departments, with an additional 400 working at a virtual call center staffed by the NORC research center at the University of Chicago, said Andy Owen, a state health department spokesman.

The D.C. Health Department recently added 18 case investigators to its Contact Trace Force, totaling 168, while Virginia has maintained its ranks of 1,200 case investigators and contact tracers after hiring more of those workers during the summer’s delta variant surge, officials said.

Mostly, area health officials are prioritizing their contact tracing efforts, focusing on hard-hit areas or high-risk settings, such as nursing homes and schools, as a way to limit the damage caused by the virus. They’re urging other residents who have tested positive to inform close contacts about potential exposure on their own as soon as possible, or to use smartphone apps that allow those alerts to go out anonymously.

“If we’re not able to get to people before the quarantine period ends, it really doesn’t add anything to help them,” said David Goodfriend, health director in Virginia’s Loudoun County, which has seen more than 800 new cases per day and has 42 contact tracers working full-time or part-time.

“In addition to that, we’re seeing more and more folks getting tested through home test kits,” he said. “So, we don’t ever see those results and are not able to provide appropriate contact tracing.”

Goodfriend said his department is working on a public awareness campaign to urge all residents who’ve tested positive to notify anyone they may have exposed as soon as possible, a step other localities have also either taken or are planning.

In Maryland, state health officials are planning to roll out a web survey for infected residents to complete so contact tracers can quickly identify people who are most at risk of severe illness or are in locations where rapid transmission is likely.

The onslaught of new infections can feel overwhelming nearly two years into the pandemic, particularly to the contact tracers working to stem the tide, said Elaine Perry, the interim health director in Virginia’s Central Shenandoah Health District, where the omicron variant is just now taking hold.

“It is hard when you look at a long queue of cases and know that you’re not going to get to all of them,” Perry said. “But we’re just trying to remind them: ‘Everyone you get to is still somebody you’re able to help.’”

Watson said health officials were wrong to reduce their ranks of contact tracers during lulls in the pandemic, arguing that that’s when the effort is more effective.

“It becomes more useful and more important as we get lower case numbers because we can further drive down transmission and, hopefully, get us to a more sustainable place,” she said.

For now, with the omicron variant invading virtually every aspect of society, most people should assume that they’ve come within striking range of the virus if they’ve been closer than six feet to someone else, particularly indoors, Goodfriend said.

“Wherever you go, you’re likely coming into contact with the virus now,” he said. “Even if everyone is doing everything right — fully vaccinated, wearing a mask — it doesn’t prevent you from potentially getting infected.”