The first case of person-to-person spread of the 2019 novel coronavirus (2019-nCoV) emerging in the United States has occurred, as the husband of a previously identified case in Illinois has been hospitalized, the CDC reported on Jan. 30. The man is the first U.S. case with no history of travel to China.

Public health officials announced the woman became ill after returning from Wuhan, China, the epicenter of what is threatening to become a global outbreak. She has been hospitalized, and her husband became ill and also was hospitalized. They both are in stable condition.

The CDC cautioned against over-reaction, like wearing surgical masks in public, as the number of cases in the U.S. is only at six. Limited person-to-person spread also has been seen in nine other countries, as people traveling from Wuhan infect their close contacts.

All six U.S. patients have survived and all are thought to remain hospitalized. In addition to Illinois, the first five infections in American patients were in travelers who returned from Wuhan to Washington state, California, and Arizona. All their contacts are being traced to detect any other transmission.

Although it was soon followed by other cases, the first case of 2019-nCoV in the United States was unusual in that a self-aware patient who became ill after traveling from Wuhan, China, essentially self-diagnosed and reported for care.

The man returned from Wuhan on a connecting flight into Seattle-Tacoma International Airport in Washington, the CDC reported at a Jan. 21 press conference. He showed no symptoms of illness since leaving China, but was closely following his vital signs for the fever and cough that mark the onset of the coronavirus infection. He had not visited any animal markets in China, the patient said.

“This was a very astute gentleman who was looking at internet activity, had actually researched this, and shared this information with his provider on Jan. 19,” said Scott Lindquist, MD, state epidemiologist for communicable diseases in Washington.

At a Jan. 21 press conference, Nancy Messonnier, director of CDC’s National Center for Immunization and Respiratory Diseases, immediately drew a distinction between the new coronavirus and the Ebola virus that infected two U.S. nurses in Dallas in 2014.

“It’s actually important to clarify that the precautions for this patient are standard isolation precautions,” she said. “This is something many hospitals know how to do, and we’re grateful that in this region in Washington state they were quite prepared for this contingency. This is not a situation like the Dallas one. This is something where most hospitals in the region should have a hospital that can utilize these kinds of precautions.”

The CDC is calling for standard, contact, droplet, and airborne precautions that include an N95 respirator. Most hospitals can implement those, but it bears recalling that the CDC started its Ebola response by saying any hospital could handle a case of that virus. Ebola patients eventually were transferred to biocontainment facilities with considerably more protection for healthcare workers.

“We are very comfortable that this patient is isolated, poses very little risk to the staff or the general public in this current situation,” Lindquist said. “Because of an abundance of caution, we have used pretty strict isolation requirements and hospitalization because it is the first person in the United States.”

The patient was recovering in a hospital and no secondary cases have been identified. Four additional U.S. patients — all travelers from Wuhan — were identified shortly after the first case, with patients hospitalized in Illinois, California, and Arizona. Again, no transmission has been found in any contacts of these patients. The CDC is investigating 80 people in the U.S. as possible cases, and predicts that more will be identified linked to travel from China.

“Right now, we have only a handful of patients with this virus in the U.S.,” Messonnier said. “We’re conducting contact tracing for every one of these patients. Contacts are watched for multiple days after the last day they were in contact with the patient. If the contact develops a fever or respiratory symptoms, they will be tested to see if they are also infected. We think this strategy will enable us to contain the outbreak.”

As this story was filed, the CDC advised all U.S. citizens to avoid nonessential travel to China.

“While it’s possible that some person-to-person spread with this virus may be detected in the United States, the goal of the ongoing U.S. public health response is to contain this outbreak and prevent sustained spread in this country,” the CDC stated.