U.S. ED staff already had their hands full treating patients presenting with influenza; now, there is another pathogen to be concerned about: a novel coronavirus.

This pathogen has sickened hundreds of patients with pneumonia in Wuhan City, China, a significant transportation hub about 700 miles south of Beijing. Several patients there have died from the illness since the pathogen was identified in recent weeks

On Jan. 21, the CDC confirmed the first case of coronavirus in the United States. The agency reported a resident of Washington state was hospitalized with the illness after returning from a trip to Wuhan City. The man, described as being in his 30s, is reported to be in good condition, and health authorities are investigating whether there are any additional exposures related to this first case.

Days before the CDC confirmed the first U.S. case, Nancy Messonnier, MD, director of the agency’s National Center for Immunization and Respiratory Diseases, addressed why this outbreak is of particular concern. “We have faced this challenge before, first with SARS [Severe Acute Respiratory Syndrome Coronavirus] and later with MERS [Middle Eastern Respiratory Syndrome Coronavirus]. Both outbreaks were complex and required a comprehensive public health response,” she said during a Jan. 17 telebriefing. “Because of that experience, we know it is crucial to be proactive and prepared.”

Messonnier said any time there is a new virus or pathogen emerging in a population that has not experienced it before, that population has not built immunity, and there are no specific treatments or vaccines to address the bug.

“Understanding that this pathogen looks, at least from a genetic perspective, like [MERS and SARS] makes us especially worried,” she said. “It doesn’t take much for a virus in general to go from being worrisome to being extremely worrisome because [viruses] tend to morph and mutate a lot. That’s why in this class of viruses, we are especially worried, and we’re taking a very cautious and proactive approach.”

While it is rare for animal coronaviruses to infect people and for the illness to then spread between people, that is what happened in the case of SARS and MERS. There are indications that the newly discovered coronavirus has followed a similar pathway, according to Messonnier. “Most of the patients in the outbreak have reportedly had some link to a large seafood and live animal market, which does suggest an animal to human spread,” she explained.

While the market was closed in early January for disinfection and cleaning, new cases involving the novel coronavirus continue to be identified, Messonnier indicated. She added that reports from China suggest some patients have become seriously ill from the coronavirus, while others have recovered and are feeling better.

The response to this newly discovered pathogen is early, but Messonnier said the CDC does have some information with which to work in preparing for new cases. “Our laboratory is using genetic sequences [of the coronavirus] provided by the Chinese, and already has the ability to identify this pathogen,” she said. This testing was conducted within a day in the case of the individual diagnosed with the illness in Washington state.

The genetic sequence has been made available to scientists around the world, which is how cases in Thailand, Japan, and South Korea were confirmed, Messonnier noted.

Investigators in those countries compared the genetic sequences they found in samples from their patients to the sequence the Chinese collaborators shared. The CDC is working on a more specific diagnostic test that it will be distributing to state health departments and others soon.

The CDC has begun screening most passengers arriving in the United States on direct and connecting flights from Wuhan City. This screening is taking place at John F. Kennedy International Airport in New York City, San Francisco International Airport, and Los Angeles International Airport. These three airports receive the vast majority of travelers from Wuhan City, noted Martin Cetron, MD, director of the CDC’s Division of Global Migration and Quarantine, during the Jan. 17 telebriefing.

Plans also have been established to begin screening patients at Hartsfield-Jackson International Airport in Atlanta and O’Hare International Airport in Chicago.

Any passengers who raise concerns based on their symptoms, temperature, and link to Wuhan City will be moved to a tertiary screening process. During this further investigation, quarantine medical officers will ask questions about exposure to family members and others. Also, individuals who are ill will undergo further evaluation at predesignated facilities that can perform a diagnostic workup. This includes collecting specimens that will be sent to the CDC for reference testing for the novel coronavirus.

“We have been through this type of protocol before in 2014 and 2016 during Ebola entry screening, which lasted many months,” Cetron noted. In a similar fashion, individuals requiring further evaluation will be transported safely without exposing others, and they will be evaluated under CDC guidance for infection control precautions and recommendations, he added.

Considering all this is happening in the middle of respiratory virus season, Cetron stressed that it will be much more likely that travelers identified for further evaluation actually will be suffering from influenza, parainfluenza, or respiratory syncytial virus.

“We have been in contact with some of our partners that are screening in other countries, and it is our understanding that they had screened thousands before they found [cases involving the novel coronavirus],” he explained. “We are expecting this is going to be a triage scenario, and there is the capability in these referral centers for doing rapid diagnostics for the other causes of respiratory illness.”

Cetron added that the symptom-based entry screening process at U.S. airports is just one aspect of a multilayered response that also includes alerting the country’s public health and healthcare delivery systems.

“When used with other public health measures already in place for the rapid detection of ill-arriving travelers, we can slow and reduce the spread of disease into the United States,” he explained.

The CDC has issued a Health Alert Network (HAN) message containing interim guidance for healthcare providers regarding the outbreak and when they should consider the novel coronavirus in patients who present with fever and respiratory symptoms. Recent travel to Wuhan City or exposure to someone who has recently visited the area should raise suspicions that the novel coronavirus could be the cause of a patient’s illness.

Some hospitals are reportedly already implementing electronic prompts to question patients about recent travel to China, or association with any people who have recently visited the country. The HAN alert provides instructions regarding infection control procedures, specimen collection, and how to report such cases to the CDC. (Editor’s Note: Much more information can be found online at: http://bit.ly/2TPrr3d.) “We are preparing across the public health and healthcare [delivery] system to prevent, detect, and respond to this novel coronavirus,” Cetron reported. “The earlier we detect a case, the better we can protect the public and the more we can understand about this virus and its risk for spread.”

Cetron cautioned it is still early in this outbreak, and more guidance and details likely will be forthcoming soon. “While we have experience with SARS and MERS, humility is important,” he said. “As we learn more about this newly emerging virus, CDC will adjust its screening and response procedures appropriately.”

(Editor’s Note: As of Jan. 27, there have been five confirmed coronavirus cases in the United States, with dozens of other pending cases under review. Updates and more information is available from the CDC online at: http://bit.ly/3aLTVB3.)