Coronavirus in the United States: What We Know About Confirmed and Suspected Cases

Multiple cases of a novel coronavirus known to cause pneumonia have been found in the United States, and more than 70 others are awaiting test results.

"We understand many people in the United States are worried about this virus and how it will affect Americans," Dr. Nancy Messonnier, director of the Center for the National Center for Immunization and Respiratory Diseases, told reporters on Monday. "Risk depends on exposure."

Temporarily named 2019-nCoV, the virus originated in Wuhan, China, but has since spread to at least 12 countries, according to the World Health Organization (WHO). The vast majority of the 2,798 confirmed cases are confined to China, but as of Monday five people in America had tested positive for the virus.

The Centers for Disease Control and Prevention has developed a diagnostic test for the virus and is working on a plan to make it accessible to individual states. As of Monday, the CDC is the only agency within the United States with the capability of diagnosing the virus, so all samples must be sent there for processing. At this time, a centralized process ensures the most accurate results, according to Messonnier.

"Our most important priority is making sure that the test is accurate," she said on a press call. "Speed is important, but accuracy is probably a priority."

Generally, she said, the time between the decision that a patient should be tested and the result is around one day, depending on where the person is located and shipping efficiency.

Suspected Cases

As of Monday, there have been 110 suspected cases of 2019-nCoV in the U.S., involving people in 26 states, according to the CDC. Thirty-two samples have tested negative, and 73 are still waiting for results. Messonnier declined to say which states submitted samples, referring reporters to state health departments.

Among the suspected cases is a student from White Mountain School in Bethlehem, New Hampshire. The student returned to the U.S. from China on January 6 and went to Littleton Regional Healthcare on Thursday with mild flu-like symptoms, according to the New Hampshire hospital. Measures were taken to prevent cross-contamination until the CDC confirms test results.

On Monday, New York Governor Andrew Cuomo confirmed that the Department of Health was still awaiting test results for five individuals. Cases are also suspected in Maryland and San Diego County, California.

Symptoms of the new strain of coronavirus include fever, cough and shortness of breath. These symptoms are also characteristic of a number of other respiratory viruses, so the virus' presence in an area can be confirmed only by a positive test result.

coronavirus us confirmed suspected cases
The Department of Health and Human Services will be holding a press conference today on their coordinated public health response to the 2019 coronavirus (2019-nCoV) on Tuesday in Washington, D.C. As of Tuesday morning, there were only five confirmed cases of coronavirus in the U.S. and about 70 were still awaiting test results. Samuel Corum/Getty

Confirmed Cases

On Sunday, the CDC confirmed there have been five cases of coronavirus in the U.S., equivalent to about 13 percent of those who had been tested. Two cases were identified in California, while Arizona, Washington and Illinois each had one confirmed case.

Every one of the five confirmed cases involved someone who recently traveled to Wuhan, and human-to-human transmission has not been identified in the U.S. The CDC predicted that would likely change, however.

To prevent additional cases of the virus appearing in the U.S., the CDC updated its travel guidelines on Monday to advise people to avoid traveling to any part of China. The agency has also implemented health screenings at more than a dozen airports to detect the virus in high-risk travelers.

Expectations for Future Cases

Messonnier told reporters on Monday that the number of suspected cases will "only increase," and the CDC said it's likely cases will include person-to-person spread in the coming days or weeks. The agency's goal, meanwhile, is to respond in a way that prevents sustained spread in America.

Since the virus hadn't spread within communities where cases were confirmed, Messonnier said, the immediate health risk to the general public is believed to be low.