Four more people have died of the novel coronavirus in Washington, hospital and health officials announced at a news conference this morning, bringing the total number of deaths from COVID-19 in the state and the country to six.

Five King County residents and one Snohomish County resident have died at EvergreenHealth in Kirkland. So far the majority of the deaths are in patients who had underlying health conditions.

There are currently 18 confirmed cases in Washington, with tests running multiple times a day at the public health lab in Shoreline. Health officials announced that the University of Washington also will begin testing today or Tuesday. Health officials are preparing for an increase of cases statewide as testing capabilities expand.

“We expect the number of cases to increase in the next days and weeks, and we’re taking this situation very seriously,” Dr. Jeff Duchin, King County health officer, said. “The risk for all of us to become infected is increasing.”

That said, officials reiterated that COVID-19, which is a respiratory virus that presents with flu-like symptoms including cough, fever or difficulty breathing, is more dangerous for people with underlying health conditions and those over the age of 60.

The majority of people with COVID-19 will have mild illness, Kathy Lofy, state health officer, said, while a small portion will have severe illness and require hospitalization.

The only confirmed cases of COVID-19 in Washington so far are in Snohomish and King counties.

“We have not detected cases outside of King and Snohomish Counties, but given the movement, it is possible the virus is appearing in other counties too,” Lofy said.

Stevens, Grant and Spokane Counties are monitoring a person from each county who have been tested for COVID-19. Test results are still pending, and results will be available in the coming days.

Dow Constantine, King County executive, declared a state of emergency on Monday to allow the county to purchase a motel where patients can recover in isolation, and other modular units to house patients who are homeless.

Health officials asked the public to refrain from buying masks so that health care workers can have access to the supplies they need to care for those with COVID-19. People experiencing symptoms are asked to call their health care providers if they are concerned about symptoms and not go to emergency departments first. Officials encouraged the public to practice good hand health hygiene and stay home from work or school if they are sick.

“Wash your hands frequently. More hand washing, less face touching. Avoid contact with ill persons and if you are ill don’t go to work or school,” Duchin said on Monday.

While King County officials did not recommend the widespread cancellation of events or schools, they did say people who are over the age of 60 or who have chronic, underlying health conditions should consider avoiding crowded settings. Health officials also encouraged people to avoid touching their eyes, nose and mouth without washing their hands.

Current testing protocols, outlined by the Centers for Disease Control and Prevention, only allow health care providers to test patients with symptoms who also have traveled to China, Iran, Italy, Japan and South Korea recently or who have been in close contact with a person who has a confirmed case of COVID-19. Additionally, health care providers can test a person with severe respiratory illness that is hospitalized. This measure is how doctors at EvergreenHealth found COVID-19 had spread at Life Care Center, an assisted living facility in Kirkland.

Due to narrow CDC testing guidelines and the fact that some people will only have mild symptoms related to the virus, Duchin said,

“There are likely many mild cases in the community that we’re not aware of.

“The cases our health care colleagues are finding are the tip of the iceberg: patients that are hospitalized with severe illness.”

In future days and weeks, Duchin said the public health response will likely shift to not counting the number of positive COVID-19 cases but instead working on a community-based approach, as is done with influenza.

“We are going to see a lot of sick people, and we will have a tremendous challenge on our health care system,” Duchin said.

As testing becomes more widespread, Duchin said it could be used much like testing for the flu.

“This disease will need to be managed like a seasonal influenza. Many people will have it, (but) not many will be seriously ill.”

This story is developing and will be updated.